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Tilley HB, Murphy D, Wierucka K, Wong TC, Surreault-Châble A, Mumby HS. Physical activity and temperature changes of Asian elephants (Elephas maximus) participating in eco-tourism activities and elephant polo. PLoS One 2024; 19:e0300373. [PMID: 38696403 PMCID: PMC11065253 DOI: 10.1371/journal.pone.0300373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Accepted: 02/26/2024] [Indexed: 05/04/2024] Open
Abstract
Captive and domestic animals are often required to engage in physical activity initiated or organised by humans, which may impact their body temperature, with consequences for their health and welfare. This is a particular concern for animals such as elephants that face thermoregulatory challenges because of their body size and physiology. Using infrared thermography, we measured changes in skin temperature associated with two types of physical activity in ten female Asian elephants (Elephas maximus) at an eco-tourism lodge in Nepal. Six elephants took part in an activity relatively unfamiliar to the elephants-a polo tournament-and four participated in more familiar ecotourism activities. We recorded skin temperatures for four body regions affected by the activities, as well as an average skin temperature. Temperature change was used as the response variable in the analysis and calculated as the difference in elephant temperature before and after activity. We found no significant differences in temperature change between the elephants in the polo-playing group and those from the non-polo playing group. However, for both groups, when comparing the average skin body temperature and several different body regions, we found significant differences in skin temperature change before and after activity. The ear pinna was the most impacted region and was significantly different to all other body regions. This result highlights the importance of this region in thermoregulation for elephants during physical activity. However, as we found no differences between the average body temperatures of the polo and non-polo playing groups, we suggest that thermoregulatory mechanisms can counteract the effects of both physical activities the elephants engaged in.
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Affiliation(s)
- Hannah B. Tilley
- Applied Behavioural Ecology and Conservation Lab, Area of Ecology and Biodiversity, School of Biological Sciences, The University of Hong Kong, Hong Kong, Hong Kong SAR
| | - Derek Murphy
- Applied Behavioural Ecology and Conservation Lab, Area of Ecology and Biodiversity, School of Biological Sciences, The University of Hong Kong, Hong Kong, Hong Kong SAR
- German Primate Centre—Leibniz Institute for Primate Research, Cognitive Ethology Laboratory, Göttingen, Germany
- Department for Primate Cognition, Johann-Friedrich-Blumenbach Institute, Georg-August-Universität Göttingen, Göttingen, Germany
| | - Kaja Wierucka
- Applied Behavioural Ecology and Conservation Lab, Area of Ecology and Biodiversity, School of Biological Sciences, The University of Hong Kong, Hong Kong, Hong Kong SAR
- German Primate Center–Leibniz Institute for Primate Research, Behavioural Ecology and Sociobiology Unit, Göttingen, Germany
| | - Tsz Ching Wong
- Applied Behavioural Ecology and Conservation Lab, Area of Ecology and Biodiversity, School of Biological Sciences, The University of Hong Kong, Hong Kong, Hong Kong SAR
| | - Annaëlle Surreault-Châble
- Laboratoire Ethologie Cognition Développement, Université Paris Nanterre, Paris, France
- Le PAL, Saint-Pourçain-sur-Besbre, Allier, France
| | - Hannah S. Mumby
- Applied Behavioural Ecology and Conservation Lab, Area of Ecology and Biodiversity, School of Biological Sciences, The University of Hong Kong, Hong Kong, Hong Kong SAR
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Klinhom S, Sriwichaiin S, Kerdphoo S, Khonmee J, Chattipakorn N, Chattipakorn SC, Thitaram C. Characteristics of gut microbiota in captive Asian elephants (Elephas maximus) from infant to elderly. Sci Rep 2023; 13:23027. [PMID: 38155244 PMCID: PMC10754835 DOI: 10.1038/s41598-023-50429-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 12/19/2023] [Indexed: 12/30/2023] Open
Abstract
Gut microbiota play an important role in the health and disease of Asian elephants, however, its characteristics at each stage of life have not been thoroughly investigated in maintaining and regulating health of elephants. This study, therefore, aimed to characterize the profiles of the gut microbiota of captive Asian elephants from infants to the elderly. Gut microbiota were identified by 16S rRNA sequencing from the feces of captive Asian elephants with varying age groups, including infant calves, suckling calves, weaned calves, subadult and adult elephants, and geriatric elephants. The diversity of the gut microbiota was lowest in infants, stable during adulthood, and slightly decreased in the geriatric period. The gut microbiota of the infant elephants was dominated by milk-fermenting taxa including genus Bifidobacterium of family Bifidobacteriaceae together with genus Akkermansia. The fiber-fermenting taxa such as Lachnospiraceae_NK3A20_group were found to be increased in suckling elephants in differential abundance analysis by Analysis of Compositions of Microbiomes with Bias Correction (ANCOM-BC). The gut microbiota profiles after weaning until the adult period has been uniform as indicated by no significant differences in beta diversity between groups. However, the composition of the gut microbiota was found to change again in geriatric elephants. Understanding of the composition of the gut microbiota of captive Asian elephants at various life stages could be beneficial for promoting good health throughout their lifespan, as well as ensuring the welfare of captive elephants.
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Affiliation(s)
- Sarisa Klinhom
- Center of Elephant and Wildlife Health, Animal Hospital, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, 50100, Thailand
| | - Sirawit Sriwichaiin
- Cardiac Electrophysiology Unit, Department of Physiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, 50200, Thailand
- Center of Excellence in Cardiac Electrophysiology Research, Chiang Mai University, Chiang Mai, 50200, Thailand
- Neurophysiology Unit, Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai, 50200, Thailand
| | - Sasiwan Kerdphoo
- Center of Excellence in Cardiac Electrophysiology Research, Chiang Mai University, Chiang Mai, 50200, Thailand
- Neurophysiology Unit, Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai, 50200, Thailand
| | - Jaruwan Khonmee
- Center of Elephant and Wildlife Health, Animal Hospital, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, 50100, Thailand
- Department of Veterinary Bioscience and Veterinary Public Health, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, 50100, Thailand
| | - Nipon Chattipakorn
- Cardiac Electrophysiology Unit, Department of Physiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, 50200, Thailand
- Center of Excellence in Cardiac Electrophysiology Research, Chiang Mai University, Chiang Mai, 50200, Thailand
- Neurophysiology Unit, Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai, 50200, Thailand
| | - Siriporn C Chattipakorn
- Center of Excellence in Cardiac Electrophysiology Research, Chiang Mai University, Chiang Mai, 50200, Thailand.
- Neurophysiology Unit, Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai, 50200, Thailand.
- Department of Oral Biology and Diagnostic Sciences, Faculty of Dentistry, Chiang Mai University, Chiang Mai, 50200, Thailand.
| | - Chatchote Thitaram
- Center of Elephant and Wildlife Health, Animal Hospital, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, 50100, Thailand.
- Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, 50100, Thailand.
- Elephant, Wildlife and Companion Animals Research Group, Chiang Mai University, Chiang Mai, 50100, Thailand.
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LaDue CA, Snyder RJ. Asian elephants distinguish sexual status and identity of unfamiliar elephants using urinary odours. Biol Lett 2023; 19:20230491. [PMID: 38115746 PMCID: PMC10731322 DOI: 10.1098/rsbl.2023.0491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Accepted: 11/30/2023] [Indexed: 12/21/2023] Open
Abstract
Despite the ubiquity of odours in mammals, few studies have documented the natural olfactory abilities of many 'non-model' species such as the Asian elephant. As Asian elephants are endangered, we may apply odours to more effectively manage threatened populations. We implemented a habituation-discrimination paradigm for the first time in Asian elephants to test the ability of elephants to discriminate between unfamiliar male elephant urine, hypothesizing that elephants would successfully distinguish non-musth from musth urine and also distinguish identity between two closely related individuals. We conducted two bioassay series, exposing three female and three male zoo-housed elephants to the same urine sample (non-musth urine in the first series, and urine from an unfamiliar individual in the second) over 5 days. On the sixth day, we simultaneously presented each elephant with a novel sample (either musth urine or urine from a second unfamiliar individual) alongside the habituated urine sample, comparing rates of chemosensory response to each sample to indicate discrimination. All elephants successfully discriminated non-musth from musth urine, and also urine from two unfamiliar half-brothers. Our results further demonstrate the remarkable olfactory abilities of elephants with promising implications for conservation and management.
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Affiliation(s)
- Chase A. LaDue
- Oklahoma City Zoo and Botanical Garden, Oklahoma City, Oklahoma, USA
| | - Rebecca J. Snyder
- Oklahoma City Zoo and Botanical Garden, Oklahoma City, Oklahoma, USA
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Pretorius Y, Eggeling T, Ganswindt A. Identifying potential measures of stress and disturbance during a captive to wild African elephant reintegration. PLoS One 2023; 18:e0291293. [PMID: 37788241 PMCID: PMC10547182 DOI: 10.1371/journal.pone.0291293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2021] [Accepted: 08/25/2023] [Indexed: 10/05/2023] Open
Abstract
There is increasing evidence of compromised welfare for elephants managed in captivity. Should such facilities eventually close, more elephants will need to be rehabilitated and reintegrated into the wild. The goal of such reintegration would be to restore any physical or psychological aspects of the elephant that may have been compromised in captivity, followed by introduction into a free-roaming system where they can interact with other elephants. However, to achieve this goal, the reintegration methods implemented need to be assessed to ensure that welfare remains the priority. The objective of this study was to test whether parameters generally associated with stress and disturbance in African elephants, respond to changes in potentially stressful environmental conditions, assessed at multiple temporal scales ranging from minutes to months. The main changes in environmental conditions that were investigated included the different phases of reintegration of a group of elephants from captivity into the wild. Stress and disturbance related parameters used for comparisons included physiological responses, namely the extent of temporal gland secretions (eTGS) and faecal glucocorticoid metabolite (fGCM) levels as well as behavioural responses, namely the display of stereotype and stress-related behaviours. Results showed that eTGS significantly increased during the initial release of the elephants compared to when in captivity. Stereotypic behaviours were only recorded during the captive phase and immediately ceased after release. Faecal GCM levels spiked in the first year after release before decreasing back to pre-reintegration levels during the third year. These findings indicate that fGCM levels, the eTGS and disturbance related behaviours all proved effective in explaining the changes in stress and disturbance experienced by elephants during the initial years after being reintegrated from captivity into the wild.
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Affiliation(s)
| | | | - Andre Ganswindt
- Mammal Research Institute, University of Pretoria, Hatfield, South Africa
- Endocrine Research Laboratory, Department of Anatomy and Physiology, University of Pretoria, Pretoria, South Africa
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5
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Fletcher RJ, O'Brien A, Hall TF, Jones M, Potash AD, Kruger L, Simelane P, Roques K, Monadjem A, McCleery RA. Frightened of giants: fear responses to elephants approach that of predators. Biol Lett 2023; 19:20230202. [PMID: 37817576 PMCID: PMC10565413 DOI: 10.1098/rsbl.2023.0202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2023] [Accepted: 09/15/2023] [Indexed: 10/12/2023] Open
Abstract
Animals are faced with a variety of dangers or threats, which are increasing in frequency with ongoing environmental change. While our understanding of fearfulness of such dangers is growing in the context of predation and parasitism risk, the extent to which non-trophic, interspecific dangers elicit fear in animals remains less appreciated. We provide an experimental test for fear responses of savannah ungulates to a dominant and aggressive megaherbivore, the African bush elephant (Loxodonta africana), and contrast responses to an apex predator known to elicit fear in this system. Using an automated behavioural response system, we contrast vigilance and run responses of ungulates to elephant, leopard (Panthera pardus), and control (red-chested cuckoo Cuculus solitarius) vocalizations. Overall, we find that ungulates responded to elephant calls, both in terms of an increase in run and vigilance responses relative to controls. The magnitude of most behavioural responses (four of six considered) to elephant vocalizations were not significantly different than responses to leopards. These results suggest that megaherbivores can elicit strong non-trophic fear responses by ungulates and call to broaden frameworks on fear to consider dominant species, such as megaherbivores, as key modifiers of fear-induced interactions.
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Affiliation(s)
- Robert J. Fletcher
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, FL 32611, USA
| | - Amanda O'Brien
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, FL 32611, USA
| | - Timothy F. Hall
- School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Maggie Jones
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, FL 32611, USA
| | - Alex D. Potash
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, FL 32611, USA
| | | | - Phumlile Simelane
- All Out Africa, Savannah Research Centre, Mbuluzi Game Reserve, Lubombo, Eswatini
| | - Kim Roques
- All Out Africa, Savannah Research Centre, Mbuluzi Game Reserve, Lubombo, Eswatini
| | - Ara Monadjem
- Department of Biological Sciences, University of Eswatini, Kwaluseni, Eswatini
- Mammal Research Institute, Department of Zoology & Entomology, University of Pretoria, Pretoria, South Africa
| | - Robert A. McCleery
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, FL 32611, USA
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6
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Kurz MJ, Hutchinson JR. Visual feedback influences the consistency of the locomotor pattern in Asian elephants ( Elephas maximus). Biol Lett 2023; 19:20230260. [PMID: 37753637 PMCID: PMC10523196 DOI: 10.1098/rsbl.2023.0260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 09/08/2023] [Indexed: 09/28/2023] Open
Abstract
Elephants are atypical of most quadrupeds in that they maintain the same lateral sequence footfall pattern across all locomotor speeds. It has been speculated that the preservation of the footfall patterns is necessary to maintain a statically stable support polygon. This should be a particularly important constraint in large, relatively slow animals. This suggests that elephants must rely on available sensory feedback mechanisms to actively control their massive pillar-like limbs for proper foot placement and sequencing. How the nervous system of elephants integrates the available sensory information for a stable gait is unknown. Here we explored the role that visual feedback plays in the control of the locomotor pattern in Asian elephants. Four Asian elephants (Elephas maximus) walked with and without a blindfold as we measured their stride time intervals. Coefficient of variation was used to assess changes in the overall variability of the stride time intervals, while approximate entropy was used to measure the stride-to-stride consistency of the time intervals. We show that visual feedback plays a role in the stride-to-stride consistency of the locomotor pattern in Asian elephants. These results suggest that elephants use visual feedback to correct and maintain proper sequencing of the limbs during locomotion.
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Affiliation(s)
- Max J. Kurz
- Institute for Human Neuroscience, Boys Town National Research Hospital, 14090 Mother Teresa Lane, Boys Town, NE 68010, USA
| | - John R. Hutchinson
- Structure and Motion Laboratory, Department of Comparative Biomedical Sciences, The Royal Veterinary College, University of London, Hatfield, Hertfordshire AL9 7TA, UK
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7
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Schulz AK, Reidenberg JS, Ning Wu J, Ying Tang C, Seleb B, Mancebo J, Elgart N, Hu DL. Elephant trunks use an adaptable prehensile grip. Bioinspir Biomim 2023; 18:026008. [PMID: 36652720 DOI: 10.1088/1748-3190/acb477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Accepted: 01/18/2023] [Indexed: 06/17/2023]
Abstract
Elephants have long been observed to grip objects with their trunk, but little is known about how they adjust their strategy for different weights. In this study, we challenge a female African elephant at Zoo Atlanta to lift 20-60 kg barbell weights with only its trunk. We measure the trunk's shape and wrinkle geometry from a frozen elephant trunk at the Smithsonian. We observe several strategies employed to accommodate heavier weights, including accelerating less, orienting the trunk vertically, and wrapping the barbell with a greater trunk length. Mathematical models show that increasing barbell weights are associated with constant trunk tensile force and an increasing barbell-wrapping surface area due to the trunk's wrinkles. Our findings may inspire the design of more adaptable soft robotic grippers that can improve grip using surface morphology such as wrinkles.
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Affiliation(s)
- Andrew K Schulz
- Schools of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, United States of America
- Max Planck Institute for Intelligent Systems, Stuttgart, Germany
| | - Joy S Reidenberg
- Center for Anatomy and Functional Morphology, Icahn School of Medicine at Mount Sinai, New York, NY, United States of America
| | - Jia Ning Wu
- School of Additive Manufacturing, Sun Yat-Sen University, Shenzhen, People's Republic of China
| | - Cheuk Ying Tang
- Radiology, Neuroscience, & Psychiatry Translation and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States of America
| | - Benjamin Seleb
- Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, United States of America
| | - Josh Mancebo
- Zoo Atlanta, Atlanta, GA 30315, United States of America
| | - Nathan Elgart
- Zoo Atlanta, Atlanta, GA 30315, United States of America
| | - David L Hu
- Schools of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, United States of America
- Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, United States of America
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Wells HBM, Porensky LM, Veblen KE, Riginos C, Stringer LC, Dougill AJ, Namoni M, Ekadeli J, Young TP. At high stocking rates, cattle do not functionally replace wild herbivores in shaping understory community composition. Ecol Appl 2022; 32:e2520. [PMID: 34918420 DOI: 10.1002/eap.2520] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 07/09/2021] [Accepted: 09/09/2021] [Indexed: 06/14/2023]
Abstract
Over a quarter of the world's land surface is grazed by cattle and other livestock, which are replacing wild herbivores, potentially impairing ecosystem structure, and functions. Previous research suggests that cattle at moderate stocking rates can functionally replace wild herbivores in shaping understory communities. However, it is uncertain whether this is also true under high stocking rates and the effects of wild herbivore on plant communities are moderate, enhanced, or simply additive to the effects of cattle at high stocking rates. To evaluate the influence of cattle stocking rates on the ability of cattle to functionally replace wild herbivores and test for interactive effects between cattle and wild herbivores in shaping understory vegetation, we assessed herbaceous vegetation in a long-term exclosure experiment in a semi-arid savanna in central Kenya that selectively excludes wild mesoherbivores (50-1000 kg) and megaherbivores (elephant and giraffe). We tested the effects of cattle stocking rate (zero/moderate/high) on herbaceous vegetation (diversity, composition, leafiness). We also tested how those effects depend on the presence of wild mesoherbivores and megaherbivores. We found that herbaceous community composition (primary ordination axis) was better explained by the presence/absence of herbivore types than by total herbivory, suggesting that herbivore identity is a more important determinant of community composition than total herbivory at high cattle stocking rates. The combination of wild mesoherbivores and cattle stocked at high rates led to increased bare ground and annual grass cover, reduced perennial grass cover and understory leafiness, and enhanced understory diversity. These shifts were weaker or absent when cattle were stocked at high stocking rates in the absence of wild mesoherbivores. Megaherbivores tempered the effects of cattle stocked at high rates on herbaceous community composition but amplified the effects of high cattle stocking rate on bare ground and understory diversity. Our results show that cattle at high stocking rates do not functionally replace wild herbivores in shaping savanna herbaceous communities contrary to previous findings at moderate stocking rates. In mixed-use rangelands, interactions between cattle stocking rate and wild herbivore presence can lead to non-additive vegetation responses with important implications for both wildlife conservation and livestock production.
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Affiliation(s)
- Harry B M Wells
- Sustainability Research Institute, School of Earth and Environment, University of Leeds, Leeds, UK
- Lolldaiga Hills Research Programme, Nanyuki, Kenya
- Space for Giants, Nanyuki, Kenya
| | - Lauren M Porensky
- Mpala Research Centre, Nanyuki, Kenya
- USDA-ARS Rangeland Resources Research Unit, Fort Collins, Colorado, USA
| | - Kari E Veblen
- Mpala Research Centre, Nanyuki, Kenya
- Department of Wildland Resources and Ecology Center, Utah State University, Logan, Utah, USA
| | - Corinna Riginos
- Mpala Research Centre, Nanyuki, Kenya
- The Nature Conservancy, Lander, Wyoming, USA
| | - Lindsay C Stringer
- Sustainability Research Institute, School of Earth and Environment, University of Leeds, Leeds, UK
- Department of Environment and Geography, University of York, York, UK
| | - Andrew J Dougill
- Sustainability Research Institute, School of Earth and Environment, University of Leeds, Leeds, UK
| | | | | | - Truman P Young
- Mpala Research Centre, Nanyuki, Kenya
- Department of Plant Sciences and Ecology Graduate Group, University of California, Davis, California, USA
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Garai ME, Roos T, Eggeling T, Ganswindt A, Pretorius Y, Henley M. Developing welfare parameters for African elephants (Loxodonta africana) in fenced reserves in South Africa. PLoS One 2022; 17:e0264931. [PMID: 35324916 PMCID: PMC8947097 DOI: 10.1371/journal.pone.0264931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 02/21/2022] [Indexed: 12/02/2022] Open
Abstract
South Africa has many fenced reserves harbouring small to medium sized populations of African elephant (Loxodonta africana), most of which have been translocated. Elephants on fenced reserves may be exposed to various management interventions and practices (translocation, hunting, darting, high tourism impact, contraception programs, disruption due to infrastructure maintenance, etc.). These factors may impact the welfare of elephants. Poor elephant welfare may have serious consequences such as increased inter- and intra-species aggression that could result in fatalities. This is the first study to attempt to define behavioural and physiological welfare parameters for free-ranging elephants on small to medium sized reserves. The eight study sites incorporated reserves with different social structure combinations, elephant life-histories, reserve sizes, habitat, management, and tourism intensity. Data collection consisted of behavioural observations (10-minute videos) as well as faecal samples. By incorporating both behavioural and physiological (faecal glucocorticoid metabolite (fGCM) concentration) parameters, we aimed to investigate whether the two parameters showed similar trends. Five behavioural categories were identified (Arousal, Assessing, Ambivalent, Ambivalent/ Body care, and Frustrated behaviour), with various detailed behaviours demonstrated by the elephants that may indicate the influence of anthropogenic disturbance and possibly impact on animal welfare. The study showed significant differences between the selected detailed behaviours, behavioural categories and fGCM concentrations of elephants across the eight reserves. History seemed to be a decisive factor, as reserves with predominantly ex-captive elephants showed higher frequencies of certain behaviours as well as higher fGCM concentrations. Age, sex, reserve size and season were also found to contribute to our defined welfare indices and fGCM concentrations. This indicates that behavioural parameters, indicative of certain behavioural states, are valuable indicators of welfare, as supported by the physiological response of the elephants. The results also highlight the importance of taking multiple specified behaviours from a category into consideration when evaluating the welfare of elephants, to account for individual variation.
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Affiliation(s)
| | - Tenisha Roos
- Elephant Reintegration Trust, Port Alfred, South Africa
| | | | - André Ganswindt
- Mammal Research Institute, University of Pretoria, Pretoria, South Africa
| | | | - Michelle Henley
- Applied Behavioural Ecology and Environmental Research Unit, University of South Africa, Pretoria, South Africa
- Elephants Alive, Hoedspruit, Limpopo, South Africa
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Wiśniewska M, Puga-Gonzalez I, Lee P, Moss C, Russell G, Garnier S, Sueur C. Simulated poaching affects global connectivity and efficiency in social networks of African savanna elephants—An exemplar of how human disturbance impacts group-living species. PLoS Comput Biol 2022; 18:e1009792. [PMID: 35041648 PMCID: PMC8797174 DOI: 10.1371/journal.pcbi.1009792] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 01/28/2022] [Accepted: 12/23/2021] [Indexed: 11/19/2022] Open
Abstract
Selective harvest, such as poaching, impacts group-living animals directly through mortality of individuals with desirable traits, and indirectly by altering the structure of their social networks. Understanding the relationship between disturbance-induced, structural network changes and group performance in wild animals remains an outstanding problem. To address this problem, we evaluated the immediate effect of disturbance on group sociality in African savanna elephants—an example, group-living species threatened by poaching. Drawing on static association data from ten free-ranging groups, we constructed one empirically based, population-wide network and 100 virtual networks; performed a series of experiments ‘poaching’ the oldest, socially central or random individuals; and quantified the immediate change in the theoretical indices of network connectivity and efficiency of social diffusion. Although the social networks never broke down, targeted elimination of the socially central conspecifics, regardless of age, decreased network connectivity and efficiency. These findings hint at the need to further study resilience by modeling network reorganization and interaction-mediated socioecological learning, empirical data permitting. The main contribution of our work is in quantifying connectivity together with global efficiency in multiple social networks that feature the sociodemographic diversity likely found in wild elephant populations. The basic design of our simulation makes it adaptable for hypothesis testing about the consequences of anthropogenic disturbance or lethal management on social interactions in a variety of group-living species with limited, real-world data.
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Affiliation(s)
- Maggie Wiśniewska
- Department of Biological Sciences, New Jersey Institute of Technology, Newark, New Jersey, United States of America
- * E-mail:
| | - Ivan Puga-Gonzalez
- Institutt for global utvikling og samfunnsplanlegging, Universitetet i Agder, Kristiansand, Norway
- Center for Modeling Social Systems at NORCE, Kristiansand, Norway
| | - Phyllis Lee
- Amboseli Trust for Elephants, Nairobi, Kenya
- Faculty of Natural Science, University of Stirling, Stirling, United Kingdom
| | | | - Gareth Russell
- Department of Biological Sciences, New Jersey Institute of Technology, Newark, New Jersey, United States of America
| | - Simon Garnier
- Department of Biological Sciences, New Jersey Institute of Technology, Newark, New Jersey, United States of America
| | - Cédric Sueur
- Université de Strasbourg, CNRS, IPHC, UMR 7178, Strasbourg, France
- Institut Universitaire de France, Paris, France
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11
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Fuchs E, Beeck VC, Baotic A, Stoeger AS. Acoustic structure and information content of trumpets in female Asian elephants (Elephas maximus). PLoS One 2021; 16:e0260284. [PMID: 34813615 PMCID: PMC8610244 DOI: 10.1371/journal.pone.0260284] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Accepted: 11/05/2021] [Indexed: 12/02/2022] Open
Abstract
Most studies on elephant vocal communication have focused on the low-frequency rumble, with less effort on other vocalization types such as the most characteristic elephant call, the trumpet. Yet, a better and more complete understanding of the elephant vocal system requires investigating other vocalization types and their functioning in more detail as well. We recorded adult female Asian elephants (Elephas maximus) at a private facility in Nepal and analyzed 206 trumpets from six individuals regarding their frequency, temporal and contour shape, and related acoustic parameters of the fundamental frequency. We also tested for information content regarding individuality and context. Finally, we recorded the occurrence of non-linear phenomena such as bifurcation, biphonation, subharmonics and deterministic chaos. We documented a mean fundamental frequency ± SD of 474 ± 70 Hz and a mean duration ± SD of 1.38 ± 1.46 s (Nindiv. = 6, Ncalls = 206). Our study reveals that the contour of the fundamental frequency of trumpets encodes information about individuality, but we found no evidence for trumpet subtypes in greeting versus disturbance contexts. Non-linear phenomena prevailed and varied in abundance among individuals, suggesting that irregularities in trumpets might enhance the potential for individual recognition. We propose that trumpets in adult female Asian elephants serve to convey an individual’s identity as well as to signal arousal and excitement to conspecifics.
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Affiliation(s)
- Evelyn Fuchs
- Mammal Communication Lab, Department of Behavioral and Cognitive Biology, University of Vienna, Vienna, Austria
| | - Veronika C. Beeck
- Mammal Communication Lab, Department of Behavioral and Cognitive Biology, University of Vienna, Vienna, Austria
| | - Anton Baotic
- Mammal Communication Lab, Department of Behavioral and Cognitive Biology, University of Vienna, Vienna, Austria
| | - Angela S. Stoeger
- Mammal Communication Lab, Department of Behavioral and Cognitive Biology, University of Vienna, Vienna, Austria
- * E-mail:
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12
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Abstract
Elephants exhibit remarkable vocal plasticity, and case studies reveal that individuals of African savannah (Loxodonta africana) and Asian (Elephas maximus) elephants are capable of vocal production learning. Surprisingly, however, little is known about contextual learning (usage and comprehension learning) in elephant communication. Usage learning can be demonstrated by training animals to vocalize in an arbitrary (cue-triggered) context. Here we show that adult African savannah elephants (n = 13) can vocalize in response to verbal cues, reliably producing social call types such as the low-frequency rumble, trumpets and snorts as well as atypical sounds using various mechanisms, thus displaying compound vocal control. We further show that rumbles emitted upon trainer cues differ significantly in structure from rumbles triggered by social contexts of the same individuals (n = 6). Every form of social learning increases the complexity of a communication system. In elephants, we only poorly understand their vocal learning abilities and the underlying cognitive mechanisms. Among other research, this calls for controlled learning experiments in which the prerequisite is operant/volitional control of vocalizations. This article is part of the theme issue 'Vocal learning in animals and humans'.
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Affiliation(s)
- Angela S. Stoeger
- Mammal Communication Laboratory, Department of Behavioral and Cognitive Biology, University of Vienna, Vienna, Austria
| | - Anton Baotic
- Mammal Communication Laboratory, Department of Behavioral and Cognitive Biology, University of Vienna, Vienna, Austria
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13
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Neto de Carvalho C, Belaústegui Z, Toscano A, Muñiz F, Belo J, Galán JM, Gómez P, Cáceres LM, Rodríguez-Vidal J, Cunha PP, Cachão M, Ruiz F, Ramirez-Cruzado S, Giles-Guzmán F, Finlayson G, Finlayson S, Finlayson C. First tracks of newborn straight-tusked elephants (Palaeoloxodon antiquus). Sci Rep 2021; 11:17311. [PMID: 34531420 PMCID: PMC8445925 DOI: 10.1038/s41598-021-96754-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 08/10/2021] [Indexed: 02/07/2023] Open
Abstract
Tracks and trackways of newborns, calves and juveniles attributed to straight-tusked elephants were found in the MIS 5 site (Upper Pleistocene) known as the Matalascañas Trampled Surface (MTS) at Huelva, SW Spain. Evidence of a snapshot of social behaviour, especially parental care, can be determined from the concentration of elephant tracks and trackways, and especially from apparently contemporaneous converging trackways, of small juvenile and larger, presumably young adult female tracks. The size frequency of the tracks enabled us to infer body mass and age distribution of the animals that crossed the MTS. Comparisons of the MTS demographic frequency with the morphology of the fore- and hind limbs of extant and fossil proboscideans shed light into the reproductive ecology of the straight-tusked elephant, Palaeloxodon antiquus. The interdune pond habitat appeared to have been an important water and food resource for matriarchal herds of straight-tusked elephants and likely functioned as a reproductive habitat, with only the rare presence of adult and older males in the MTS. The preservation of this track record in across a paleosol surface, although heavily trampled by different animals, including Neanderthals, over a short time frame, permitted an exceptional view into short-term intraspecific trophic interactions occurring in the Last Interglacial coastal habitat. Therefore, it is hypothesized that Neanderthals visited MTS for hunting or scavenging on weakened or dead elephants, and more likely calves.
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Affiliation(s)
- Carlos Neto de Carvalho
- Naturtejo UNESCO Global Geopark, Geology Office of the Municipality of Idanha-a-Nova, Idanha-a-Nova, Portugal
- Instituto D. Luiz, University of Lisbon, Lisbon, Portugal
| | - Zain Belaústegui
- Departament de Dinàmica de la Terra i de L'Oceà, Facultat de Ciències de la Terra, Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona (UB), Barcelona, Spain
| | - Antonio Toscano
- Departamento de Ciencias de la Tierra, Universidad de Huelva, Huelva, Spain
| | - Fernando Muñiz
- Departamento de Cristalografía, Mineralogía y Química Agrícola, Universidad de Sevilla, Seville, Spain
| | - João Belo
- Geosciences Center, University of Coimbra, FlyGIS-UAV Surveys, Coimbra, Portugal
| | - Jose María Galán
- Centro Administrativo del Acebuche, Parque Nacional de Doñana, Matalascañas, Huelva, Spain
| | - Paula Gómez
- Departamento de Ciencias de la Tierra, Universidad de Huelva, Huelva, Spain
| | - Luis M Cáceres
- Departamento de Ciencias de la Tierra, Universidad de Huelva, Huelva, Spain.
| | | | - Pedro Proença Cunha
- Department of Earth Sciences, MARE-Marine and Environmental Sciences Centre, University of Coimbra, Coimbra, Portugal
| | - Mario Cachão
- Instituto D. Luiz, University of Lisbon, Lisbon, Portugal
- Department of Geology, Faculty of Sciences, University of Lisbon, 1749-016, Lisbon, Portugal
| | - Francisco Ruiz
- Departamento de Ciencias de la Tierra, Universidad de Huelva, Huelva, Spain
| | | | | | - Geraldine Finlayson
- The Gibraltar National Museum, Gibraltar, UK
- Institute of Life and Earth Sciences, University of Gibraltar, Gibraltar, UK
- Department of Life Sciences, Liverpool John Moores University, Liverpool, UK
| | - Stewart Finlayson
- The Gibraltar National Museum, Gibraltar, UK
- Institute of Life and Earth Sciences, University of Gibraltar, Gibraltar, UK
| | - Clive Finlayson
- The Gibraltar National Museum, Gibraltar, UK
- Institute of Life and Earth Sciences, University of Gibraltar, Gibraltar, UK
- Department of Life Sciences, Liverpool John Moores University, Liverpool, UK
- Department of Anthropology, University of Toronto, Scarborough Campus, Toronto, Canada
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14
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Liehrmann O, Crawley JAH, Seltmann MW, Feillet S, Nyein UK, Aung HH, Htut W, Lahdenperä M, Lansade L, Lummaa V. Handler familiarity helps to improve working performance during novel situations in semi-captive Asian elephants. Sci Rep 2021; 11:15480. [PMID: 34326446 PMCID: PMC8322261 DOI: 10.1038/s41598-021-95048-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 07/19/2021] [Indexed: 11/12/2022] Open
Abstract
Working animals spend hours each day in close contact with humans and require training to understand commands and fulfil specific tasks. However, factors driving cooperation between humans and animals are still unclear, and novel situations may present challenges that have been little-studied to-date. We investigated factors driving cooperation between humans and animals in a working context through behavioural experiments with 52 working semi-captive Asian elephants. Human-managed Asian elephants constitute approximately a third of the remaining Asian elephants in the world, the majority of which live in their range countries working alongside traditional handlers. We investigated how the familiarity and experience of the handler as well as the elephant's age and sex affected their responses when asked to perform a basic task and to cross a novel surface. The results highlighted that when novelty is involved in a working context, an elephant's relationship length with their handler can affect their cooperation: elephants who had worked with their handler for over a year were more willing to cross the novel surface than those who had a shorter relationship with their handler. Older animals also tended to refuse to walk on the novel surface more but the sex did not affect their responses. Our study contributes much needed knowledge on human-working animal relationships which should be considered when adjusting training methods and working habits.
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Affiliation(s)
- Océane Liehrmann
- Department of Biology, University of Turku, 20500, Turku, Finland.
| | | | | | - Sherine Feillet
- Department of Biology, University of Turku, 20500, Turku, Finland
- Université Sorbonne Paris Nord, 93430, Villetaneuse, France
| | - U Kyaw Nyein
- Myanma Timber Enterprise, Gyogone Forest Compound, Bayint Naung Road, Insein Township, Yangon, 11011, Myanmar
| | - Htoo Htoo Aung
- Myanma Timber Enterprise, Gyogone Forest Compound, Bayint Naung Road, Insein Township, Yangon, 11011, Myanmar
| | - Win Htut
- Myanma Timber Enterprise, Gyogone Forest Compound, Bayint Naung Road, Insein Township, Yangon, 11011, Myanmar
| | - Mirkka Lahdenperä
- Department of Public Health, University of Turku and Turku University Hospital, 20520, Turku, Finland
| | - Léa Lansade
- CNRS, IFCE, INRAE, Université de Tours, PRC, 37380, Nouzilly, France
| | - Virpi Lummaa
- Department of Biology, University of Turku, 20500, Turku, Finland
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15
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Sun Y, Chen Y, Díaz-Sacco JJ, Shi K. Assessing population structure and body condition to inform conservation strategies for a small isolated Asian elephant (Elephas maximus) population in southwest China. PLoS One 2021; 16:e0248210. [PMID: 33690688 PMCID: PMC7942997 DOI: 10.1371/journal.pone.0248210] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Accepted: 02/22/2021] [Indexed: 11/24/2022] Open
Abstract
The Asian elephant (Elephas maximus) population in Nangunhe National Nature Reserve in China represents a unique evolutionary branch that has been isolated for more than twenty years from neighboring populations in Myanmar. The scarcity of information on population structure, sex ratio, and body condition makes it difficult to develop effective conservation measures for this elephant population. Twelve individuals were identified from 3,860 valid elephant images obtained from February to June 2018 (5,942 sampling effort nights) at 52 camera sites. Three adult females, three adult males, one subadult male, two juvenile females, two juvenile males and one male calf were identified. The ratio of adult females to adult males was 1:1, and the ratio of reproductive ability was 1:0.67, indicating the scarcity of reproductive females as an important limiting factor to population growth. A population density of 5.32 ± 1.56 elephants/100 km2 was estimated using Spatially Explicit Capture Recapture (SECR) models. The health condition of this elephant population was assessed using an 11-point scale of Body Condition Scoring (BCS). The average BCS was 5.75 (n = 12, range 2–9), with adult females scoring lower than adult males. This isolated population is extremely small and has an inverted pyramid age structure and therefore is at a high risk of extinction. We propose three plans to improve the survival of this population: improving the quality and quantity of food resources, removing fencing and establishing corridors between the east and wet parts of Nangunhe reserve.
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Affiliation(s)
- Yakuan Sun
- School of Ecology and Nature Conservation, Beijing Forestry University, Beijing, China
| | - Ying Chen
- School of Biological Science, The University of Hong Kong, Hong Kong, China
| | - Juan José Díaz-Sacco
- School of Ecology and Nature Conservation, Beijing Forestry University, Beijing, China
| | - Kun Shi
- School of Ecology and Nature Conservation, Beijing Forestry University, Beijing, China
- Eco-Bridge Continental, Beijing, China
- * E-mail:
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16
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Glaeser SS, Edwards KL, Wielebnowski N, Brown JL. Effects of physiological changes and social life events on adrenal glucocorticoid activity in female zoo-housed Asian elephants (Elephas maximus). PLoS One 2020; 15:e0241910. [PMID: 33156856 PMCID: PMC7647113 DOI: 10.1371/journal.pone.0241910] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2020] [Accepted: 10/22/2020] [Indexed: 11/25/2022] Open
Abstract
Ensuring good health and welfare is an increasingly important consideration for conservation of endangered species and includes breeding of individuals managed under human care. Understanding how factors in the captive environment affect individual animal wellbeing can be aided by long-term monitoring of biological functioning. This study involved longitudinal assessments (4 to 28 years) of reproductive and adrenal hormones in zoo-housed female Asian elephants (Elephas maximus) (age range 4 to ~71 years) to elucidate patterns in adrenal glucocorticoid (GC) activity in association with reproductive and demographic factors, and examine individual response to major social changes. Concentrations of serum and urinary cortisol covaried more consistently with physiological changes (ovarian cycle phase, puberty, pregnancy, lactational anestrus, and age) than with social life events (births, deaths, and facility transfers). Cortisol fluctuated across the ovarian cycle with mean concentrations being higher in the follicular than in the luteal phase, and concentrations were highest in lactational anestrous compared to all other reproductive states. The elephants in this study exhibited substantial individuality in adrenal GC response to major social change, reinforcing the need to assess welfare on an individual basis and to consider factors influencing the impact of perceived stressors, such as social relationships, social support, temperament, and life history. Outcomes from this study deepen our understanding of Asian elephant physiology and highlight the importance of taking intrinsic patterns of hormone secretion into account when evaluating the impact of external factors. Finally, a better understanding of the impact of social change and resiliency in response to real and perceived stressors allows us to improve social management to enhance welfare in both captive settings and free-ranging environments.
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Affiliation(s)
| | - Katie L. Edwards
- Center for Species Survival, Smithsonian Conservation Biology Institute, Smithsonian National Zoological Park, Front Royal, Virginia, United States of America
- North of England Zoological Society, Chester Zoo, Upton-by-Chester, United Kingdom
| | | | - Janine L. Brown
- Center for Species Survival, Smithsonian Conservation Biology Institute, Smithsonian National Zoological Park, Front Royal, Virginia, United States of America
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17
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Prado NA, Carlstead K, Malloy EJ, Paris S, Wielebnowski N, Rockwood LL, Brown JL. Ovarian cyclicity and prolactin status of African elephants (Loxodonta africana) in North American zoos may be influenced by life experience and individual temperament. Horm Behav 2020; 125:104804. [PMID: 32531397 DOI: 10.1016/j.yhbeh.2020.104804] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 04/21/2020] [Accepted: 06/05/2020] [Indexed: 11/23/2022]
Abstract
Hyperprolactinemia is an endocrine disorder associated with infertility in many species, including elephants. In a recent survey of zoos accredited by the Association of Zoos and Aquariums (AZA), over half of African elephant females (N = 101) were not cycling normally, 30% of which exhibited hyperprolactinemia. We examined whether life experience and temperament predict ovarian cyclicity and circulating prolactin status in individual African elephant females. We hypothesized that, similar to humans, acyclicity and hyperprolactinemia in elephants will be associated with an apprehensive or fearful, anxious temperament, and an increased number of potentially challenging life events (transfers, deaths and births). Ninety-five adult African elephant females housed at 37 AZA institutions were included in this study. Blood samples were collected twice a month for 1 year to determine ovarian cycle (cycling, n = 44; irregular, n = 13; non-cycling, n = 38) and prolactin (normal, n = 44; low; n = 23; high; n = 28) status. Keeper ratings on a 6-point scale were obtained on 32 temperament traits in 85 of these elephants. We determined that giving birth and being exposed to herd mates entering the facility were positively associated with normal ovarian cycle and prolactin profiles. By contrast, age, serum cortisol, and an increased number of herd mates leaving a facility were negatively associated with both. Contrary to our hypothesis, hyperprolactinemia was associated with a popular and caring temperament rating, whereas consistently low prolactin was associated with a fearful, apprehensive temperament. These findings indicate that pituitary-ovarian function may be impacted by life history (cyclicity) and temperament (prolactin), which should be taken into consideration when making management decisions.
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Affiliation(s)
- Natalia A Prado
- Center for Species Survival, Smithsonian Conservation Biology Institute, Front Royal, VA, USA.
| | - Kathy Carlstead
- Center for Species Survival, Smithsonian Conservation Biology Institute, Front Royal, VA, USA
| | - Elizabeth J Malloy
- Department of Mathematics and Statistics, American University, 4400 Massachusetts Ave. NW, Washington, DC, USA
| | - Stephen Paris
- Center for Species Survival, Smithsonian Conservation Biology Institute, Front Royal, VA, USA
| | | | - Larry L Rockwood
- Department of Biology, George Mason University, Fairfax, VA, USA
| | - Janine L Brown
- Center for Species Survival, Smithsonian Conservation Biology Institute, Front Royal, VA, USA
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18
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Smet AF, Byrne RW. African elephants interpret a trunk gesture as a clue to direction of interest. Curr Biol 2020; 30:R926-R927. [PMID: 32810448 DOI: 10.1016/j.cub.2020.06.070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Orienting to gaze-direction is widespread among animal species, but evidence for spontaneous use of gesture for direction is limited [1]. Remarkably, African elephants (Loxodonta africana) have been found able to follow human pointing, including subtle actions in which the contralateral hand is used, and in which the body silhouette is not broken [2,3]. The natural origin of this ability is puzzling, as the species is not reported to use trunk- or limb-gesture for showing directions [4]. One natural gesture, the 'periscope-sniff' presumed to be used to enhance olfactory sampling by an elephant in circumstances of alarm or curiosity [5], might also betray the elephant's direction of focal attention. Here we investigate what information elephants gain from seeing periscope-sniff. When one elephant in a group gave a periscope-sniff, we recorded the location and orientation of the next periscope-sniff given. Elephants that could not see the first gesturer only gestured themselves if immediately adjacent to the first or closer to the presumed stimulus of interest. In contrast, elephants able to see the first signaller's periscope-sniff were often a considerable distance behind it, further from the stimulus. Focusing on these cases, where making the periscope-sniff was apparently caused by seeing the first gesture, we found its orientation significantly matched the first, suggesting that direction information was gained from seeing the periscope-sniff. Elephants' ability to use a conspecific's periscope-sniff as if it were an ostensive pointing gesture enables them to react to the presence and location of potential dangers.
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Affiliation(s)
- Anna F Smet
- School of Psychology and Neuroscience, University of St Andrews, St Andrews, Fife KY16 9JP, UK
| | - Richard W Byrne
- School of Psychology and Neuroscience, University of St Andrews, St Andrews, Fife KY16 9JP, UK.
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19
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Brand CM, Johnson MB, Parker LD, Maldonado JE, Korte L, Vanthomme H, Alonso A, Ruiz-Lopez MJ, Wells CP, Ting N. Abundance, density, and social structure of African forest elephants (Loxodonta cyclotis) in a human-modified landscape in southwestern Gabon. PLoS One 2020; 15:e0231832. [PMID: 32348354 PMCID: PMC7190099 DOI: 10.1371/journal.pone.0231832] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 04/01/2020] [Indexed: 11/28/2022] Open
Abstract
Population monitoring is critical to effective conservation, but forest living taxa can be difficult to directly observe. This has been true of African forest elephants (Loxodonta cyclotis), for which we have limited information regarding population size and social behavior despite their threatened conservation status. In this study, we estimated demographic parameters using genetic capture-recapture of forest elephants in the southern Industrial Corridor of the Gamba Complex of Protected Areas in southwestern Gabon, which is considered a global stronghold for forest elephants. Additionally, we examined social networks, predicting that we would find matrilineal structure seen in both savanna and forest elephants. Given 95% confidence intervals, we estimate population size in the sampled area to be between 754 and 1,502 individuals and our best density estimate ranges from 0.47 to 0.80 elephants per km2. When extrapolated across the entire Industrial Corridor, this estimate suggests an elephant population size of 3,033 to 6,043 based on abundance or 1,684 to 2,832 based on density, approximately 40–80% smaller than previously suggested. Our social network analysis revealed approximately half of network components included females with different mitochondrial haplotypes suggesting a wider range of variation in forest elephant sociality than previously thought. This study emphasizes the threatened status of forest elephants and demonstrates the need to further refine baseline estimates of population size and knowledge on social behavior in this taxon, both of which will aid in determining how population dynamics in this keystone species may be changing through time in relation to increasing conservation threats.
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Affiliation(s)
- Colin M. Brand
- Department of Anthropology, University of Oregon, Eugene, OR, United States of America
| | - Mireille B. Johnson
- Gabon Biodiversity Program, Smithsonian Conservation Biology Institute, Gamba, Gabon
| | - Lillian D. Parker
- Department of Biosciences, School of Systems Biology, George Mason University, Fairfax, VA, United States of America
- Center for Conservation Genomics, Smithsonian Conservation Biology Institute, National Zoological Park, Washington, DC, United States of America
| | - Jesús E. Maldonado
- Department of Biosciences, School of Systems Biology, George Mason University, Fairfax, VA, United States of America
- Center for Conservation Genomics, Smithsonian Conservation Biology Institute, National Zoological Park, Washington, DC, United States of America
| | - Lisa Korte
- Gabon Biodiversity Program, Smithsonian Conservation Biology Institute, Gamba, Gabon
| | - Hadrien Vanthomme
- Center for Conservation and Sustainability, Smithsonian Conservation Biology Institute, National Zoological Park, Washington, DC, United States of America
| | - Alfonso Alonso
- Center for Conservation and Sustainability, Smithsonian Conservation Biology Institute, National Zoological Park, Washington, DC, United States of America
| | | | - Caitlin P. Wells
- Department of Fish, Wildlife, and Conservation Biology, Colorado State University, Fort Collins, CO, United States of America
- Institute of Ecology and Evolution, University of Oregon, Eugene, OR, United States of America
| | - Nelson Ting
- Department of Anthropology, University of Oregon, Eugene, OR, United States of America
- Institute of Ecology and Evolution, University of Oregon, Eugene, OR, United States of America
- * E-mail:
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20
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Reichert S, Berger V, Jackson J, Chapman SN, Htut W, Mar KU, Lummaa V. Maternal age at birth shapes offspring life-history trajectory across generations in long-lived Asian elephants. J Anim Ecol 2020; 89:996-1007. [PMID: 31222736 DOI: 10.1111/1365-2656.13049] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Accepted: 04/14/2019] [Indexed: 11/30/2022]
Abstract
Advanced maternal age at birth can have pronounced consequences for offspring health, survival and reproduction. If carried over to the next generation, such fitness effects could have important implications for population dynamics and the evolution of ageing, but these remain poorly understood. While many laboratory studies have investigated maternal age effects, relatively few studies have been conducted in natural populations, and they usually only present a "snapshot" of an offspring's lifetime. In the present study, we focus on how maternal age influences offspring life-history trajectories and performance in a long-lived mammal. We use a multigenerational demographic dataset of semi-captive Asian elephants to investigate maternal age effects on several offspring life-history traits: condition, reproductive success and overall survival. We show that offspring born to older mothers display reduced overall survival but higher reproductive success, and reduced survival of their own progeny. Our results show evidence of a persistent effect of maternal age on fitness across generations in a long-lived mammal. By highlighting transgenerational effects on the fitness of the next generation associated with maternal age, the present study helps increase our understanding of factors contributing to individual variation in ageing rates and fitness.
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Affiliation(s)
- Sophie Reichert
- Department of Biology, University of Turku, Turku, Finland
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
| | - Vérane Berger
- Department of Biology, University of Turku, Turku, Finland
| | - John Jackson
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, UK
| | | | - Win Htut
- Ministry of Natural Resources and Environmental Conservation, Myanma Timber Enterprise, Yangon, Myanmar
| | - Khyne U Mar
- Department of Biology, University of Turku, Turku, Finland
| | - Virpi Lummaa
- Department of Biology, University of Turku, Turku, Finland
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21
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Hambrecht S, Oerke AK, Heistermann M, Dierkes PW. Diurnal variation of salivary cortisol in captive African elephants (Loxodonta africana) under routine management conditions and in relation to a translocation event. Zoo Biol 2020; 39:186-196. [PMID: 32134143 DOI: 10.1002/zoo.21537] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 11/24/2019] [Accepted: 02/21/2020] [Indexed: 01/20/2023]
Abstract
The present study assessed the diurnal variation in salivary cortisol in captive African elephants during routine management (baseline) and in relation to a potential stressor (translocation) to evaluate to what extent acute stress may affect diurnal cortisol patterns. Under baseline conditions, we collected morning and afternoon saliva samples of 10 animals (three zoos) on different days in two study periods (n = 3-10 per animal, daytime and period). Under stress conditions, we sampled the transported cow (newcomer) and the two cows of the destination zoo before and after the transport in the morning and afternoon (n = 3-9 per animal, daytime and transport phase), as well as after the first introduction of the newcomer to the bull (n = 1 per animal). Cortisol was measured in unextracted samples by enzyme immunoassay. Under baseline conditions, we observed the expected diurnal variation with higher cortisol levels in the morning than in the afternoon. Under stress conditions, neither a significant difference between pre- and posttransport, nor between morning and afternoon levels was found. The percentage difference between morning and afternoon cortisol after the transport, however, was remarkably lower than before the transport in the newcomer potentially indicating a stress response to familiarization. Saliva samples taken immediately after the introduction of the newcomer to the bull revealed a marked cortisol increase. Our findings indicate that stressors may disturb the diurnal cortisol rhythm. Furthermore, provided that samples can be collected promptly, salivary cortisol is a useful minimally invasive measure of physiological stress in the African elephant.
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Affiliation(s)
- Susan Hambrecht
- Bioscience Education and Zoo Biology, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Ann-Kathrin Oerke
- Endocrinology Laboratory, German Primate Centre, Leibniz Institute for Primate Research, Göttingen, Germany
| | - Michael Heistermann
- Endocrinology Laboratory, German Primate Centre, Leibniz Institute for Primate Research, Göttingen, Germany
| | - Paul Wilhelm Dierkes
- Bioscience Education and Zoo Biology, Goethe University Frankfurt, Frankfurt am Main, Germany
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22
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Abstract
BACKGROUND The existence of extended post-reproductive lifespan is an evolutionary puzzle, and its taxonomic prevalence is debated. One way of measuring post-reproductive life is with post-reproductive representation, the proportion of adult years lived by females after cessation of reproduction. Analyses of post-reproductive representation in mammals have claimed that only humans and some toothed whale species exhibit extended post-reproductive life, but there are suggestions of a post-reproductive stage for false killer whales and Asian elephants. Here, we investigate the presence of post-reproductive lifespan in Asian elephants using an extended demographic dataset collected from semi-captive timber elephants in Myanmar. Furthermore, we investigate the sensitivity of post-reproductive representation values to availability of long-term data over 50 years. RESULTS We find support for the presence of an extended post-reproductive stage in Asian elephants, and that post-reproductive representation and its underlying demographic rates depend on the length of study period in a long-lived animal. CONCLUSIONS The extended post-reproductive lifespan is unlikely due to physiological reproductive cessation, and may instead be driven by mating preferences or condition-dependent fertility. Our results also show that it is crucial to revisit such population measures in long-lived species as more data is collected, and if the typical lifespan of the species exceeds the initial study period.
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Affiliation(s)
| | - John Jackson
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, UK
| | - Win Htut
- Myanma Timber Enterprise, Ministry of Natural Resources and Environment Conservation, Yangon, Myanmar
| | - Virpi Lummaa
- Department of Biology, University of Turku, Turku, Finland
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23
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Chusyd DE, Brown JL, Golzarri-Arroyo L, Dickinson SL, Johnson MS, Allison DB, Nagy TR. Fat mass compared to four body condition scoring systems in the Asian elephant (Elephas maximus). Zoo Biol 2019; 38:424-433. [PMID: 31361060 PMCID: PMC6786925 DOI: 10.1002/zoo.21508] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 06/06/2019] [Accepted: 07/08/2019] [Indexed: 12/25/2022]
Abstract
Captive elephant populations are not self-sustaining due to health concerns possibly related to obesity. Categorizing obesity relies on qualitative analyses like body condition scores (BCS). However, elephant indices have not been validated against measured body composition. The objective was to compare BCS systems to body composition determined by deuterium dilution in 28 zoo-kept Asian elephants. Elephants were weighed and given deuterated water orally (0.05 ml/kg). Blood was collected at ~0, 24, 120, 240, 360, and 480 hr after dosing. Photographs were taken to score the elephant based on four BCS systems (BCSWemmer [0 to 11 scoring], BCSMorfeld [1 to 5 scoring], BCSFernando [0 to 10 scoring], BCSWijeyamohan [1 to 10 scoring]). Based on regression analysis, relative fat ranged from -305 kg to 515 kg, where negative values indicate less and positive values indicate more fat than expected for the elephant's mass in this population. BCSFernando was associated with relative fat (p = .020, R2 = 0.194). Relative fat, adjusted for sex and age in the statistical model, was associated with BCSWemmer (p = .027, R2 = 0.389), BCSFernando (p = .002, R2 = 0.502), and BCSWijeyamohan (p = .011, R2 = 0.426). Inclusion of zoo and familial relatedness resulted in all BCS systems associated with relative fat (p ≤ .015). Only BCSFernando predicted relative fat, unadjusted, suggesting it is the most capable system for practical use. Compared to absolute fat, relative fat may be more biologically relevant as greater fat relative to body mass is more likely to lead to health issues.
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Affiliation(s)
- Daniella E. Chusyd
- Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Janine L. Brown
- Department of Reproductive Sciences, Conservation & Research Center, National Zoological Park, Smithsonian Institution, Front Royal, VA, USA
| | | | | | - Maria S. Johnson
- Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, AL, USA
| | - David B. Allison
- School of Public Health, Indiana University-Bloomington, Bloomington, IN, USA
| | - Tim R. Nagy
- Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, AL, USA
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24
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Lynch EC, Lummaa V, Htut W, Lahdenperä M. Evolutionary significance of maternal kinship in a long-lived mammal. Philos Trans R Soc Lond B Biol Sci 2019; 374:20180067. [PMID: 31303162 PMCID: PMC6664136 DOI: 10.1098/rstb.2018.0067] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/06/2018] [Indexed: 11/12/2022] Open
Abstract
Preferential treatment of kin is widespread across social species and is considered a central prerequisite to the evolution of cooperation through kin selection. Though it is well known that, among most social mammals, females will remain within their natal group and often bias social behaviour towards female maternal kin, less is known about the fitness consequences of these relationships. We test the fitness benefits of living with maternal sisters, measured by age-specific female reproduction, using an unusually large database of a semi-captive Asian elephant ( Elephas maximus) population. This study system is particularly valuable to an exploration of reproductive trends in a long-lived mammal, because it includes life-history data that span multiple generations, enabling a study of the effects of kinship across a female's lifespan. We find that living near a sister significantly increased the likelihood of annual reproduction among young female elephants, and this effect was strongest when living near a sister 0-5 years younger. Our results show that fitness benefits gained from relationships with kin are age-specific, establish the basis necessary for the formation and maintenance of close social relationships with female kin, and highlight the adaptive importance of matriliny in a long-lived mammal. This article is part of the theme issue 'The evolution of female-biased kinship in humans and other mammals'.
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Affiliation(s)
- Emily C. Lynch
- Department of Biology, University of Turku, Turku 20014, Finland
| | - Virpi Lummaa
- Department of Biology, University of Turku, Turku 20014, Finland
| | - Win Htut
- Myanma Timber Enterprise, Ministry of Natural Resources and Environment Conservation, Yangon, Myanmar
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25
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Edwards KL, Miller MA, Carlstead K, Brown JL. Relationships between housing and management factors and clinical health events in elephants in North American zoos. PLoS One 2019; 14:e0217774. [PMID: 31170219 PMCID: PMC6553755 DOI: 10.1371/journal.pone.0217774] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Accepted: 05/17/2019] [Indexed: 02/07/2023] Open
Abstract
Elephants experience a number of health issues that can contribute to their well-being and survival. In managed populations, housing conditions and management practices can influence individual health, so potential risk factors associated with morbidity or mortality should be identified to ensure the best possible standards of care. The goal of this study was to determine if the number of clinical events experienced could be a useful welfare indicator in zoo elephants, and to determine factors associated with key pathologies. We used an epidemiological approach to investigate how intrinsic (species, sex, age) and extrinsic (housing, management) factors were associated with both the total number of clinical events, and each of the four most prevalent pathology types (gastrointestinal issues, skin lesions, lameness, foot lesions), over a 12-month period. The study included 220 (127 African; 93 Asian) elephants housed at 61 facilities across North America. More than 1100 clinical events were identified. Species and sex differences were apparent in the types of pathology encountered, and unsurprisingly, the number of clinical events was positively correlated with age. Factors relating to housing (percent time with indoor/outdoor choice, space experience inside, number of unique environments an elephant was housed in, percent time on soft substrate) and management (enrichment diversity, spread of feeding opportunities) were also related to the number of clinical events. However, relationships were often counter to our initial hypotheses, highlighting caution in assuming cause and effect from correlational analyses such as these. Other welfare indicators such as serum and fecal glucocorticoids and serum prolactin were also associated with health status, being higher or more variable in individuals with a greater number of events. This approach provides insight into housing and management factors related to the health of these species in zoos, and in some cases, may reflect management changes that have already been made to mitigate existing or anticipated health concerns.
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Affiliation(s)
- Katie L. Edwards
- Center for Species Survival, Smithsonian Conservation Biology Institute, Front Royal, Virginia, United States of America
- * E-mail:
| | - Michele A. Miller
- Department of Science and Technology-National Research Foundation Centre of Excellence for Biomedical TB Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Kathy Carlstead
- Center for Species Survival, Smithsonian Conservation Biology Institute, Front Royal, Virginia, United States of America
| | - Janine L. Brown
- Center for Species Survival, Smithsonian Conservation Biology Institute, Front Royal, Virginia, United States of America
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26
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Prstojevich A, Uetrecht M, Watkins SN, Milanick MA. Elephants, snorkels, pressures: modeling snorkeling at depth. Adv Physiol Educ 2019; 43:155-158. [PMID: 30933537 DOI: 10.1152/advan.00191.2018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Affiliation(s)
- Alex Prstojevich
- Department of Medical Pharmacology and Physiology, University of Missouri , Columbia, Missouri
| | - Morgan Uetrecht
- Department of Medical Pharmacology and Physiology, University of Missouri , Columbia, Missouri
| | - Sidney N Watkins
- Department of Medical Pharmacology and Physiology, University of Missouri , Columbia, Missouri
| | - Mark A Milanick
- Department of Medical Pharmacology and Physiology, University of Missouri , Columbia, Missouri
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27
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Thapa K, Kelly MJ, Pradhan NMB. Elephant (Elephas maximus) temporal activity, distribution, and habitat use patterns on the tiger's forgotten trails across the seasonally dry, subtropical, hilly Churia forests of Nepal. PLoS One 2019; 14:e0216504. [PMID: 31083683 PMCID: PMC6513267 DOI: 10.1371/journal.pone.0216504] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 04/17/2019] [Indexed: 11/19/2022] Open
Abstract
Understanding spatial distribution, habitat use, and temporal activity patterns is important for species conservation planning. This information especially is crucial for mega herbivores like elephants as their ranging patterns encompass a myriad of habitats types. Churia habitat is geological fragile yet important for wildlife in Nepal and India. We used camera trapping and sign surveys covering 536 km2 of Churia and surrounding areas within Chitwan National Park. Across 152 trapping locations, we accumulated 2,097 trap nights in a 60-day survey during the winter season of 2010-11. We used a non-parametric kernel density function to analyze winter activity patterns of elephants detected in camera-traps. Additionally, we walked 643 km over 76 grid cells in two surveys (winter and summer) to estimate elephant distribution and intensity of habitat use using an occupancy framework. Multi-season models allowed us to make seasonal (winter versus summer) inferences regarding changes in habitat use based on covariates influencing use and detection. We photographed 25 mammalian species including elephants with calves with a trapping rate of 2.72 elephant photos events per 100 trap nights. Elephant winter activity pattern was found to be mainly nocturnal, with crepuscular peaks. Covariates such as normalized differential vegetation index and terrain ruggedness positively influenced elephant spatial distribution and habitat use patterns within the Churia habitat. We also found lower elephant habitat use ([Formula: see text]) of Churia in winter 0.51 (0.02) than in summer 0.57 (0.02). Elephants heavily used the eastern portion of Churia in both seasons (67-69%). Overall, Churia habitat, which is often ignored, clearly is used by elephants, with increases in summer use in the west and high use year-round in the east, and thus should no longer be neglected or forgotten in species conservation planning.
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Affiliation(s)
| | - Marcella J. Kelly
- Department of Fish and Wildlife Conservation, Virginia Tech, Blacksburg, VA, United States of America
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28
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Ngama S, Bindelle J, Poulsen JR, Hornick JL, Linden A, Korte L, Doucet JL, Vermeulen C. Do topography and fruit presence influence occurrence and intensity of crop-raiding by forest elephants (Loxodonta africana cyclotis)? PLoS One 2019; 14:e0213971. [PMID: 30901366 PMCID: PMC6430389 DOI: 10.1371/journal.pone.0213971] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Accepted: 03/05/2019] [Indexed: 11/18/2022] Open
Abstract
Crop damage by forest elephants (Loxodonta africana cyclotis) and the resulting human-elephant conflict are issues of great concern for both the conservation of the species and the protection of rural livelihoods in Central Africa. Addressing these problems requires identifying the factors that facilitate or impede crop-raiding by forest elephants. Yet to date, the environmental or anthropogenic factors that influence the occurrence and intensity of crop-raiding by forest elephants are largely unknown. We used a multivariate approach to investigate conditions under which forest elephants raid some fields and not others in the buffer zone of Monts de Cristal National Park (MCNP), Gabon. We first interviewed 121 farmers from 11 villages situated within 10 km of MCNP regarding the occurrence of elephant crop-raiding of their fields. We then collected data on 39 explanatory variables to characterize the agricultural fields. Of these, the most important predictors of elephant raid occurrence of crop damage were presence of fruit trees, elephant deterrents (scarecrows, fire, wire string fences and empty barrels), and field topography. We secondly assessed the effect of stage of crop growth, presence of fruit trees, field topography and presence of elephant deterrents on crop-raiding occurrence and intensity by counting raids and measuring areas of crop damage every week in 17 plantations over 19 weeks in the most elephant-impacted zone of the study area. We found that fruit presence and stage of crop growth led to more intense damage to crops, whereas local deterrents did not inhibit raiding events and crop damage by elephants. We report a tradeoff between non-timber forest products (NTFP) services and crop-raiding by elephants. We show for the first time that steep topography impedes elephant damage to crops with no raids recorded in fields with surrounding slopes greater than 25%. We discuss whether farming on steep fields could be used as a strategy for mitigating crop-raiding to favor human-elephant coexistence and enhance elephant conservation.
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Affiliation(s)
- Steeve Ngama
- TERRA Teaching and Research Centre, Forest Is Life, Gembloux Agro-Bio Tech, University of Liège, Gembloux, Belgium
- Laboratoire de santé et production animale, Département de Zootechnie, Institut de Recherches Agronomiques et Forestières, Centre National de la Recherche Scientifique et Technologique (IRAF-CENAREST), Libreville, Gabon
- AgroBioChem/TERRA, Precision livestock and nutrition unit/Agriculture Is Life, Gembloux Agro-Bio Tech, University of Liège, Gembloux, Belgium
- * E-mail:
| | - Jerome Bindelle
- AgroBioChem/TERRA, Precision livestock and nutrition unit/Agriculture Is Life, Gembloux Agro-Bio Tech, University of Liège, Gembloux, Belgium
| | - John R. Poulsen
- Nicholas School of the Environment, Duke University, Durham, North Carolina, United States of America
| | - Jean-Luck Hornick
- Fundamental and Applied Research on Animal and Health, Animal Production Department, Faculty of Veterinary Medicine, University of Liège, Belgium
| | - Annick Linden
- Surveillance Network of Wildlife Diseases in Southern Belgium, Faculty of Veterinary Medicine, Liege, Belgium
| | - Lisa Korte
- Independent Biodiversity and Natural Resources Specialist, Saint Cloud, MN, United States of America
| | - Jean-Louis Doucet
- TERRA Teaching and Research Centre, Forest Is Life, Gembloux Agro-Bio Tech, University of Liège, Gembloux, Belgium
| | - Cédric Vermeulen
- TERRA Teaching and Research Centre, Forest Is Life, Gembloux Agro-Bio Tech, University of Liège, Gembloux, Belgium
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29
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Seltmann MW, Helle S, Htut W, Lahdenperä M. Males have more aggressive and less sociable personalities than females in semi-captive Asian elephants. Sci Rep 2019; 9:2668. [PMID: 30804421 PMCID: PMC6390182 DOI: 10.1038/s41598-019-39915-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Accepted: 02/01/2019] [Indexed: 12/03/2022] Open
Abstract
Personality, i.e. consistent between-individual differences in behaviour, has been documented in many species. Yet little is known about how males and females of long-lived, highly social species differ in their measures of personality structure. We investigated sex differences in the mean, variance, and covariance of three previously reported personality traits (Attentiveness, Sociability, Aggressiveness) in 150 female and 107 male Asian elephants (Elephas maximus) from a semi-captive population in Myanmar. These three personality traits were obtained by performing exploratory factor analysis on 28 behavioural items that had been rated by experienced elephant handlers. We found that males scored significantly higher on Aggressiveness and tended to score lower on Sociability than females. However, no sex difference was found in the mean scores of Attentiveness. Variances for the three personality traits did not differ between the sexes, suggesting that male and female elephants share the same range of personality variation. Likewise, trait covariances were similar between the sexes. While both sexes show complex sociality in the wild, female Asian elephants typically live in highly social family units, whereas male elephants' social bonds are weaker. Males usually form dominance ranks by aggressive interactions, especially during musth. Our results on a large sample of individuals living in their natural environment are thus in agreement with elephant life-histories and parallel the findings of sex differences in other long-lived highly social species with similar life-histories.
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Affiliation(s)
| | - Samuli Helle
- Department of Biology, University of Turku, Turku, Finland
| | - Win Htut
- Myanma Timber Enterprise, Department of Timber Extraction, MOECAF, Yangoon, Myanmar
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30
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Naha D, Sathyakumar S, Dash S, Chettri A, Rawat GS. Assessment and prediction of spatial patterns of human-elephant conflicts in changing land cover scenarios of a human-dominated landscape in North Bengal. PLoS One 2019; 14:e0210580. [PMID: 30707690 PMCID: PMC6358066 DOI: 10.1371/journal.pone.0210580] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Accepted: 12/26/2018] [Indexed: 11/18/2022] Open
Abstract
It is of utmost importance to research on the spatial patterns of human-wildlife conflicts to understand the underlying mechanism of such interactions, i.e. major land use changes and prominent ecological drivers. In the north eastern part of India there has been a disparity between nature, economic development and fragmentation of wildlife habitats leading to intense conflicts between humans and Asian elephants (Elephas maximus) in recent times. Both the elephant and human population have increased in the past few decades with large tracts of forests converted to commercial tea plantations, army camps and human settlements. We analyzed data maintained by the wildlife department on human deaths and injuries caused by elephant attacks between 2006–2016 to understand spatial and temporal patterns of human-elephant conflict, frequency and distribution. The average annual number of human deaths and injuries to elephant attacks between 2006 to 2016 was estimated to be 212 (SE 103) with the highest number of such incidents recorded in 2010–2011. Based on a grid based design of 5 km2 and 25 km2 resolution, the main spatial predictors of human-elephant conflicts identified through Maxent presence only models are annual mean precipitation, altitude, distance from protected area, area under forests, tea plantations and agriculture. Major land use changes were assessed for this region from 2008 to 2018 using satellite imageries in Arc GIS and a predicted imagery of 2028 was prepared using Idrisi Selva. Based on the 2018 imagery it was found that forest area had increased by 446 km2 within 10 years (2008–2018) and the annual rate of change was 12%. Area under agriculture had reduced by 128 km2 with an annual (-) rate of change of 2.5%. Area under tea plantation declined by 307 km2 with an annual (-) rate of change of 12% whereas area under human settlements increased by 61 km2 with an annual (-) rate of change of 44%. Hotspots of human-elephant conflicts were identified in an east west direction primarily around protected areas, tea plantations and along major riverine corridors. During informal interactions with farmers, tea estate labors it was revealed that local community members chased and harassed elephants from agriculture fields, human settlements under the influence of alcohol and thus were primary victims of fatal interactions. Our analytical approach can be replicated for other species in sites with similar issues of human-wildlife conflicts. The hotspot maps of conflict risk will help in developing appropriate mitigation strategies such as setting up early warning systems, restoration of wildlife corridors especially along dry river beds, using deterrents and barriers for vulnerable. Awareness about alcohol related incidents and basic biology of elephants should be organized regularly involving non-governmental organizations targeting the marginalized farmers and tea estate workers.
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Affiliation(s)
- Dipanjan Naha
- Department of Endangered Species Management, Wildlife Institute of India, Dehradun, Uttarakhand, India
| | - S. Sathyakumar
- Department of Endangered Species Management, Wildlife Institute of India, Dehradun, Uttarakhand, India
- * E-mail:
| | - Suraj Dash
- Department of Endangered Species Management, Wildlife Institute of India, Dehradun, Uttarakhand, India
| | - Abhishek Chettri
- Department of Endangered Species Management, Wildlife Institute of India, Dehradun, Uttarakhand, India
| | - G. S. Rawat
- Faculty of Wildlife Sciences, Wildlife Institute of India, Dehradun, Uttarakhand, India
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31
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Martins AF, Bennett NC, Clavel S, Groenewald H, Hensman S, Hoby S, Joris A, Manger PR, Milinkovitch MC. Locally-curved geometry generates bending cracks in the African elephant skin. Nat Commun 2018; 9:3865. [PMID: 30279508 PMCID: PMC6168576 DOI: 10.1038/s41467-018-06257-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 08/14/2018] [Indexed: 12/22/2022] Open
Abstract
An intricate network of crevices adorns the skin surface of the African bush elephant, Loxodonta africana. These micrometre-wide channels enhance the effectiveness of thermal regulation (by water retention) as well as protection against parasites and intense solar radiation (by mud adherence). While the adaptive value of these structures is well established, their morphological characterisation and generative mechanism are unknown. Using microscopy, computed tomography and a custom physics-based lattice model, we show that African elephant skin channels are fractures of the animal brittle and desquamation-deficient skin outermost layer. We suggest that the progressive thickening of the hyperkeratinised stratum corneum causes its fracture due to local bending mechanical stress in the troughs of a lattice of skin millimetric elevations. The African elephant skin channels are therefore generated by thickening of a brittle material on a locally-curved substrate rather than by a canonical tensile cracking process caused by frustrated shrinkage.
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Affiliation(s)
- António F Martins
- Laboratory of Artificial & Natural Evolution (LANE), Department of Genetics & Evolution, University of Geneva, Geneva, 1211, Switzerland
- SIB Swiss Institute of Bioinformatics, Geneva, 1211, Switzerland
| | - Nigel C Bennett
- Mammal Research Institute, University of Pretoria, Hatfield, 0028, South Africa
| | - Sylvie Clavel
- Zoo African Safari, Plaisance du Touch, 31830, France
| | - Herman Groenewald
- Department of Anatomy & Physiology, University of Pretoria, Hatfield, 0028, South Africa
| | - Sean Hensman
- Adventures with Elephants, Bela Bela, D1000 LP, South Africa
| | | | | | - Paul R Manger
- School of Anatomical Sciences, University of the Witwatersrand, Johannesburg, Braamfontein, 2000, South Africa
| | - Michel C Milinkovitch
- Laboratory of Artificial & Natural Evolution (LANE), Department of Genetics & Evolution, University of Geneva, Geneva, 1211, Switzerland.
- SIB Swiss Institute of Bioinformatics, Geneva, 1211, Switzerland.
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Vijayakrishnan S, Kumar MA, Umapathy G, Kumar V, Sinha A. Physiological stress responses in wild Asian elephants Elephas maximus in a human-dominated landscape in the Western Ghats, southern India. Gen Comp Endocrinol 2018; 266:150-156. [PMID: 29777687 DOI: 10.1016/j.ygcen.2018.05.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 04/11/2018] [Accepted: 05/07/2018] [Indexed: 01/13/2023]
Abstract
Increasing anthropogenic pressures on forests, especially in the tropical regions of the world, have restricted several large mammalian species such as the Asian elephant to fragmented habitats within human-dominated landscapes. In this study, we assessed the effects of an anthropogenic landscape and its associated conflict with humans on the physiological stress responses displayed by Asian elephants in the Anamalai Hills of the Western Ghats mountains in south India. We have quantified faecal glucocorticoid metabolite (FGM) concentrations in focal individual elephants within and across herds, inhabiting both anthropogenic and natural habitats, and evaluated their physiological responses to different socio-ecological situations between November 2013 and April 2014. Physiological stress responses varied significantly among the tested elephant age- and sex categories but not across different types of social organisation. Adults generally showed higher FGM concentrations, even in the absence of stressors, than did any other age category. Males also appeared to have higher stress responses than did females. Although there was no significant variation in mean stress levels between elephants on the plateau in the absence of human interactions and those in adjacent, relatively undisturbed forest habitats, FGM concentrations increased significantly for adult and subadult individuals as well as for calves following drives, during which elephants were driven off aggressively by people. Our study emphasises the general importance of understanding individual variation in physiology and behaviour within a population of a seriously threatened mammalian species, the Asian elephant, and specifically highlights the need for long-term monitoring of the stress physiology and behavioural responses of individual elephants across both human-dominated and natural landscapes. Such studies would not only provide comprehensive insights into the adaptive biology of elephants in changing ecological regimes but also aid in the development of effective management and conservation strategies for endangered populations of the species.
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Affiliation(s)
- Sreedhar Vijayakrishnan
- Postgraduate Programme in Wildlife Biology and Conservation, Wildlife Conservation Society - India Program and National Centre for Biological Sciences, Bangalore, India; Nature Conservation Foundation, Mysore, India; National Institute of Advanced Studies, Bangalore, India.
| | | | - G Umapathy
- Laboratory for the Conservation of Endangered Species, Centre for Cellular and Molecular Biology, Hyderabad, India
| | - Vinod Kumar
- Laboratory for the Conservation of Endangered Species, Centre for Cellular and Molecular Biology, Hyderabad, India
| | - Anindya Sinha
- Nature Conservation Foundation, Mysore, India; National Institute of Advanced Studies, Bangalore, India; Indian Institute of Science Education and Research, Kolkata, India
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Lahdenperä M, Mar KU, Courtiol A, Lummaa V. Differences in age-specific mortality between wild-caught and captive-born Asian elephants. Nat Commun 2018; 9:3023. [PMID: 30087336 PMCID: PMC6081384 DOI: 10.1038/s41467-018-05515-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Accepted: 07/12/2018] [Indexed: 12/28/2022] Open
Abstract
Wild-capture of numerous species is common for diverse purposes, including medical experiments, conservation, veterinary interventions and research, but little objective data exists on its consequences. We use exceptional demographic records on Asian elephants from timber camps in Myanmar to investigate the long-term consequences of wild-capture during 1951-2000 on their mortality (N = 5150). We show that captured elephants have increased mortality compared to captive-born elephants, regardless of their capture method. These detrimental effects of capture are similar for both sexes but differ substantially according to age. Elephants captured and tamed at older ages show a higher increase in mortality after capture than elephants captured and tamed young. Moreover, the increased mortality risk following capture and taming is still perceived several years after capture. Our results are timely given the continued capture of elephants and other wild animals to supplement captive populations despite the alarming declines of wild populations globally.
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Affiliation(s)
| | - Khyne U Mar
- Department of Biology, University of Turku, 20014, Turku, Finland
| | - Alexandre Courtiol
- Department of Evolutionary Genetics, Leibniz Institute for Zoo and Wildlife Research, Alfred-Kowalke-Strasse, Berlin, 10315, Germany
| | - Virpi Lummaa
- Department of Biology, University of Turku, 20014, Turku, Finland
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Thammarat P, Kulsing C, Wongravee K, Leepipatpiboon N, Nhujak T. Identification of Volatile Compounds and Selection of Discriminant Markers for Elephant Dung Coffee Using Static Headspace Gas Chromatography-Mass Spectrometry and Chemometrics. Molecules 2018; 23:E1910. [PMID: 30065213 PMCID: PMC6222725 DOI: 10.3390/molecules23081910] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 07/25/2018] [Accepted: 07/27/2018] [Indexed: 11/16/2022] Open
Abstract
Elephant dung coffee (Black Ivory Coffee) is a unique Thai coffee produced from Arabica coffee cherries consumed by Asian elephants and collected from their feces. In this work, elephant dung coffee and controls were analyzed using static headspace gas chromatography hyphenated with mass spectrometry (SHS GC-MS), and chemometric approaches were applied for multivariate analysis and the selection of marker compounds that are characteristic of the coffee. Seventy-eight volatile compounds belonging to 13 chemical classes were tentatively identified, including six alcohols, five aldehydes, one carboxylic acid, three esters, 17 furans, one furanone, 13 ketones, two oxazoles, four phenolic compounds, 14 pyrazines, one pyridine, eight pyrroles and three sulfur-containing compounds. Moreover, four potential discriminant markers of elephant dung coffee, including 3-methyl-1-butanol, 2-methyl-1-butanol, 2-furfurylfuran and 3-penten-2-one were established. The proposed method may be useful for elephant dung coffee authentication and quality control.
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Affiliation(s)
- Poowadol Thammarat
- Chromatographic Separation and Flavor Chemistry Research Unit, Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand.
| | - Chadin Kulsing
- Chromatographic Separation and Flavor Chemistry Research Unit, Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand.
- Center of Molecular Sensory Science, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand.
| | - Kanet Wongravee
- Chromatographic Separation and Flavor Chemistry Research Unit, Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand.
- Center of Molecular Sensory Science, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand.
- Sensor Research Unit, Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand.
| | | | - Thumnoon Nhujak
- Chromatographic Separation and Flavor Chemistry Research Unit, Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand.
- Center of Molecular Sensory Science, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand.
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McConkey KR, Nathalang A, Brockelman WY, Saralamba C, Santon J, Matmoon U, Somnuk R, Srinoppawan K. Different megafauna vary in their seed dispersal effectiveness of the megafaunal fruit Platymitra macrocarpa (Annonaceae). PLoS One 2018; 13:e0198960. [PMID: 30020929 PMCID: PMC6051586 DOI: 10.1371/journal.pone.0198960] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 05/28/2018] [Indexed: 11/18/2022] Open
Abstract
The world’s largest terrestrial animals (megafauna) can play profound roles in seed dispersal. Yet, the term ‘megafauna’ is often used to encompass a diverse range of body sizes and physiologies of, primarily, herbivorous animals. To determine the extent to which these animals varied in their seed dispersal effectiveness (SDE), we compared the contribution of different megafauna for the large-fruited Platymitra macrocarpa (Annonaceae), in a tropical evergreen forest in Thailand. We quantified ‘seed dispersal effectiveness’ by measuring the quantity and quality contributions of all consumers of P. macrocarpa fruit. Seed dispersal quantity was the proportion of the crop consumed by each species. Quality was defined as the proportion of seeds handled by each animal taxon that survived to produce a 2-month seedling. Megafauna (elephants, sambar deer, bears) dispersed 78% of seeds that produced seedlings, with 21% dispersed by gibbons (a medium-sized frugivore). The main megafaunal consumers displayed different dispersal strategies. Elephants were the most effective dispersers (37% of seedlings) and they achieved this by being high-quality and low-quantity dispersers. Bears displayed a similar strategy but were especially rare visitors to the trees (24% of the total seedlings produced). Sambar were high-quantity dispersers, but most seeds they handled did not survive and they were responsible for only 17% of seedlings. Gibbons displayed a high SDE relative to their body size, but they probably cannot match the role of elephants despite being more regular consumers of the fruit. The low density and poor regeneration of P. macrocarpa in the study site suggest that current dispersal rates by megafauna are insufficient, possibly reflecting reduced or missing megafauna populations. We show that different megafaunal species disperse seeds in different ways and may make unique contributions to the reproductive success of the plant species.
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Affiliation(s)
- Kim R. McConkey
- School of Natural Sciences and Engineering, National Institute of Advanced Studies, Indian Institute of Science Campus, Bangalore, India
- School of Geography, University of Nottingham Malaysia Campus, Semenyih, Selangor, Malaysia
- * E-mail: (KRM); (AN)
| | - Anuttara Nathalang
- Ecology Lab, BIOTEC, National Science and Technology Development Agency, Pathum Thani, Thailand
- * E-mail: (KRM); (AN)
| | - Warren Y. Brockelman
- Ecology Lab, BIOTEC, National Science and Technology Development Agency, Pathum Thani, Thailand
- Institute of Molecular Biosciences, Mahidol University–Salaya, Phutthamonthon, Nakhon Pathom, Thailand
| | - Chanpen Saralamba
- Conservation Biology Program, Mahidol University Kanchanaburi Campus, Sai Yok, Kanchanaburi, Thailand
| | - Jantima Santon
- Ecology Lab, BIOTEC, National Science and Technology Development Agency, Pathum Thani, Thailand
| | - Umaporn Matmoon
- Ecology Lab, BIOTEC, National Science and Technology Development Agency, Pathum Thani, Thailand
| | - Rathasart Somnuk
- Ecology Lab, BIOTEC, National Science and Technology Development Agency, Pathum Thani, Thailand
| | - Kanchit Srinoppawan
- Department of National Parks, Wildlife and Plant Conservation, Chatuchak, Bangkok, Thailand
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Abstract
In "The Origin of Species," Darwin describes a hypothetical example illustrating that large, slowly reproducing mammals such as the elephant can reach very large numbers if population growth is not affected by regulating factors. The elephant example has since been cited in various forms in a wide variety of books, ranging from educational material to encyclopedias. However, Darwin's text was changed over the six editions of the book, although some errors in the mathematics persisted throughout. In addition, full details of the problem remained hidden in his correspondence with readers of the Origin. As a result, Darwin's example is very often misinterpreted, misunderstood or presented as if it were a fact. We show that the population growth of Darwin's elephant population can be modeled by the Leslie matrix method, which we generalize here to males as well. Darwin's most often cited figure, about 19 million elephants after 750 years is not a typical outcome, actually a very unlikely result under more realistic, although still hypothetical situations. We provide a recursion formula suggesting that Darwin's original model corresponds to a tribonacci series, a proof showing that sex ratio is constant over all age classes, and a derivation of a generating function of the sequence.
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Affiliation(s)
- János Podani
- Department of Plant Systematics, Ecology and Theoretical Biology, Institute of Biology, Eötvös University, Pázmány P. s. 1.C, 1117, Budapest, Hungary.
- MTA-ELTE-MTM Ecology Research Group, Eötvös University, Pázmány P. s. 1.C, 1117, Budapest, Hungary.
| | - Ádám Kun
- MTA-ELTE-MTM Ecology Research Group, Eötvös University, Pázmány P. s. 1.C, 1117, Budapest, Hungary
| | - András Szilágyi
- MTA-ELTE Theoretical Biology and Evolutionary Ecology Research Group, Eötvös University, Pázmány P. s. 1.C, 1117, Budapest, Hungary
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Abstract
With populations of African savannah elephants (Loxodonta africana) declining across the continent, assessing the status of individual elephant populations is important for conservation. Angola’s elephant population represents a key linkage between the larger populations of Namibia and Botswana. Elephants in Angola were decimated during the 1975–2002 Angolan civil war, but a 2005 survey showed that populations were recolonizing former habitats. Between 2005 and 2015, no research was permitted on elephants in Angola, but elsewhere in Africa many elephant populations experienced a poaching crisis. In 2015, we were able to resume elephant research in Angola. We used aerial surveys and satellite monitoring of collared elephants to determine the current status of elephant populations in Angola and to learn how human populations may be affecting elephant habitat usage. The aerial survey revealed a population of 3,395 ± SE of 797 elephants, but populations had declined 21% from the 2005 estimate. The high number of carcasses observed on the survey suggests that populations may have increased after the 2005 survey but were declining rapidly as of 2015. Satellite-collared elephants avoided areas <6 km from human indicators but preferred areas nearer humans at scales of 6–40 km, suggesting that humans may be displacing elephants from preferred habitats near rivers. Taken together, these results suggest that Angola’s elephant population is experiencing intense poaching and may be losing habitat to human settlements. Without action to conserve their populations, Angola’s elephants face an uncertain future.
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Affiliation(s)
| | | | - Curtice R. Griffin
- Department of Environmental Conservation, University of Massachusetts Amherst, Amherst, Massachusetts, United States of America
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Sampson C, McEvoy J, Oo ZM, Chit AM, Chan AN, Tonkyn D, Soe P, Songer M, Williams AC, Reisinger K, Wittemyer G, Leimgruber P. New elephant crisis in Asia-Early warning signs from Myanmar. PLoS One 2018. [PMID: 29534096 PMCID: PMC5849331 DOI: 10.1371/journal.pone.0194113] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
In the southern Bago Yoma mountain range in Myanmar, Asian elephants are being killed at a disturbing rate. This emerging crisis was identified initially through a telemetry study when 7 of 19 of collared elephants were poached within a year of being fitted with a satellite-GPS collar. Subsequent follow up of ground teams confirmed the human caused death or disappearance of at least 19 elephants, including the seven collared individuals, within a 35 km2 area in less than two years. The carcasses of 40 additional elephants were found in areas located across south-central Myanmar once systematic surveys began by our team and collaborators. In addition to the extreme rate of loss, this study documents the targeting of elephants for their skin instead of the more common ivory, an increasing trend in Myanmar. Intensive research programs focused on other conservation problems identified this issue and are now encouraging local authorities to prioritize anti-poaching efforts and improve conservation policies within the country. Myanmar represents one of the last remaining countries in Asia with substantial wildlands suitable for elephants. Increasing rates of human-elephant conflict and poaching events in this country pose a dire threat to the global population.
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Affiliation(s)
- Christie Sampson
- Department of Biological Sciences, Clemson University, Clemson, SC, United States of America
- Smithsonian Conservation Biology Institute, National Zoological Park, Front Royal, VA, United States of America
- * E-mail:
| | - John McEvoy
- Smithsonian Conservation Biology Institute, National Zoological Park, Front Royal, VA, United States of America
| | - Zaw Min Oo
- Myanma Timber Enterprise, Ministry of Natural Resources and Environmental Conservation, Yangon, Myanmar
| | - Aung Myo Chit
- Smithsonian Conservation Biology Institute, National Zoological Park, Front Royal, VA, United States of America
| | - Aung Nyein Chan
- Smithsonian Conservation Biology Institute, National Zoological Park, Front Royal, VA, United States of America
- Department of Fish, Wildlife, and Conservation Biology, Colorado State University, Fort Collins, CO, United States of America
- WWF–Myanmar, Yangon, Myanmar
| | - David Tonkyn
- Department of Biological Sciences, Clemson University, Clemson, SC, United States of America
- Department of Biology, University of Arkansas at Little Rock, Little Rock, AR, United States of America
| | | | - Melissa Songer
- Smithsonian Conservation Biology Institute, National Zoological Park, Front Royal, VA, United States of America
| | | | | | - George Wittemyer
- Department of Fish, Wildlife, and Conservation Biology, Colorado State University, Fort Collins, CO, United States of America
| | - Peter Leimgruber
- Smithsonian Conservation Biology Institute, National Zoological Park, Front Royal, VA, United States of America
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Morfeld KA, Brown JL. Metabolic health assessment of zoo elephants: Management factors predicting leptin levels and the glucose-to-insulin ratio and their associations with health parameters. PLoS One 2017; 12:e0188701. [PMID: 29186207 PMCID: PMC5706714 DOI: 10.1371/journal.pone.0188701] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Accepted: 11/06/2017] [Indexed: 01/11/2023] Open
Abstract
Screening for metabolic-related health problems can enhance animal welfare, so the purpose of this study was to conduct the first metabolic health assessment of zoo elephants and use epidemiological methods to determine how factors in the captive environment were associated with metabolic hormone concentrations. In addition, we examined relationships between metabolic status and several fitness parameters: foot health, musculoskeletal health, reproductive cyclicity, and body condition. Two blood samples were collected 2 weeks apart from 87 Asian (Elephas maximus) and 105 African (Loxodonta africana) elephants managed by zoos accredited by the Association of Zoos and Aquariums for analysis of serum leptin, insulin, glucose and the glucose-to-insulin ratio (G:I). In females, mean (± SD) leptin concentrations and the G:I were lower (P<0.05) in Asian (3.93 ± 2.21 ng/ml and 110 ± 86 units) compared to African (4.37 ± 2.89 ng/ml and 208 ± 133 units) elephants, respectively. For males, mean leptin and the G:I were 4.99 ± 3.61 ng/ml and 253 ± 181 units for Asian, and 3.72 ± 2.00 ng/ml and 326 ± 231 units for African elephants, respectively, with no differences between species (P>0.05). As mean leptin concentration increased there was an increase in the odds of a female being non-cycling (P = 0.0083). The G:I was associated inversely with body condition (P = 0.0002); as the G:I increased there was a decreased risk of BCS = 4 or 5 as compared to the ideal, or BCS = 3. Neither leptin nor G:I were predictive of foot or musculoskeletal health scores. Factors related to walking and feeding practices were most influential in predicting metabolic status, whereas social and housing factors showed smaller, but significant effects. The metabolic health benefits of walking were detected if the time spent in staff-directed walking was 7 hours or more per week. The most protective feeding practices included implementing a random rather than predictable feeding schedule and limiting the number of methods presentation methods. Results indicate that leptin levels and G:I can be used as predictors of both ovarian cycle function and body condition, and are affected by zoo management in elephants.
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Affiliation(s)
- Kari A. Morfeld
- Lincoln Children’s Zoo, Lincoln, Nebraska, United States of America
- Center for Species Survival, Smithsonian Conservation Biology Institute, Smithsonian National Zoological Park, Front Royal, Virginia, United States of America
| | - Janine L. Brown
- Center for Species Survival, Smithsonian Conservation Biology Institute, Smithsonian National Zoological Park, Front Royal, Virginia, United States of America
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Thuruthel TG, Falotico E, Renda F, Laschi C. Learning dynamic models for open loop predictive control of soft robotic manipulators. Bioinspir Biomim 2017; 12:066003. [PMID: 28767049 DOI: 10.1088/1748-3190/aa839f] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The soft capabilities of biological appendages like the arms of Octopus vulgaris and elephants' trunks have inspired roboticists to develop their robotic equivalents. Although there have been considerable efforts to replicate their morphology and behavior patterns, we are still lagging behind in replicating the dexterity and efficiency of these biological systems. This is mostly due to the lack of development and application of dynamic controllers on these robots which could exploit the morphological properties that a soft-bodied manipulator possesses. The complexity of these high-dimensional nonlinear systems has deterred the application of traditional model-based approaches. This paper provides a machine learning-based approach for the development of dynamic models for a soft robotic manipulator and a trajectory optimization method for predictive control of the manipulator in task space. To the best of our knowledge this is the first demonstration of a learned dynamic model and a derived task space controller for a soft robotic manipulator. The validation of the controller is carried out on an octopus-inspired soft manipulator simulation derived from a piecewise constant strain approximation and then experimentally on a pneumatically actuated soft manipulator. The results indicate that such an approach is promising for developing fast and accurate dynamic models for soft robotic manipulators while being applicable on a wide range of soft manipulators.
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41
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Abstract
Contradictory findings among scientific studies that address a particular issue may impede the conversion of science to management implementation. A systematic review of peer-reviewed studies to generate a single outcome may overcome this problem. The contentious topic of the impact that a megaherbivore such as the savanna elephant have for other species and their environment can benefit from such an approach. After some 68 years, 367 peer-reviewed papers covered the topic and 51 of these papers provided sufficient data to be included in a meta-analysis. We separated the direct impact that elephants had on trees and herbs from the indirect effects on other vertebrates, invertebrates, and soil properties. Elephants have an impact on tree structure and abundance but no overall negative cascading effects for species that share space with them. Primary productivity explained a small amount of variation of elephant impact on vegetation. Elephant numbers (density), study duration, rainfall, tree cover, and the presence of artificial water and fences failed to describe patterns of impact. We conclude that published information do not support the calls made for artificially manipulating elephant numbers to ameliorate elephant impact, and call for the management of space use by elephants to maintain savanna heterogeneity.
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Affiliation(s)
- Robert A. R. Guldemond
- Conservation Ecology Research Unit, Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
| | - Andrew Purdon
- Conservation Ecology Research Unit, Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
| | - Rudi J. van Aarde
- Conservation Ecology Research Unit, Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
- * E-mail:
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Pozo RA, Coulson T, McCulloch G, Stronza AL, Songhurst AC. Determining baselines for human-elephant conflict: A matter of time. PLoS One 2017; 12:e0178840. [PMID: 28582425 PMCID: PMC5459443 DOI: 10.1371/journal.pone.0178840] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Accepted: 05/19/2017] [Indexed: 11/18/2022] Open
Abstract
Elephant crop raiding is one of the most relevant forms of human-elephant conflict (HEC) in Africa. Northern Botswana holds the largest population of African elephants in the world, and in the eastern Okavango Panhandle, 16,000 people share and compete for resources with more than 11,000 elephants. Hence, it is not surprising this area represents a HEC ‘hotspot’ in the region. Crop-raiding impacts lead to negative perceptions of elephants by local communities, which can strongly undermine conservation efforts. Therefore, assessing trends in conflict levels is essential to developing successful management strategies. In this context, we investigated the trend in the number of reported raiding incidents as one of the indicators of the level of HEC, and assessed its relationship to trends in human and elephant population size, as well as land-use in the study area. For each of these factors, we considered data spanning historical (since the 1970s) and contemporary (2008–2015) time frames, with the aim of comparing subsequent inferences on the drivers of crop raiding and predictions for the future. We find that the level of reported crop raiding by elephants in the eastern Panhandle appears to have decreased since 2008, which seems to be related to the reduction in agricultural land allocated to people in recent years, more than with human and elephant population size. We show that inferences regarding the drivers of HEC and predictions for the future are dependent on the time span of the data used. Although our study represents a first step in developing a HEC baseline in the eastern Panhandle, it highlights the need for additional multi-scale analyses that consider progress in conservation conflict to better understand and predict drivers of HEC in the region.
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Affiliation(s)
- Rocío A. Pozo
- Department of Zoology, University of Oxford, Oxford, United Kingdom
- Ecoexist Project, Maun, Botswana
- * E-mail:
| | - Tim Coulson
- Department of Zoology, University of Oxford, Oxford, United Kingdom
| | - Graham McCulloch
- Department of Zoology, University of Oxford, Oxford, United Kingdom
- Ecoexist Project, Maun, Botswana
| | - Amanda L. Stronza
- Ecoexist Project, Maun, Botswana
- Applied Biodiversity Science Program, Texas A&M University, College Station, Texas, United States of America
| | - Anna C. Songhurst
- Department of Zoology, University of Oxford, Oxford, United Kingdom
- Ecoexist Project, Maun, Botswana
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Abstract
This study used the source and filter theory approach to analyse sex differences in the acoustic features of African elephant (Loxodonta africana) low-frequency rumbles produced in social contexts ('social rumbles'). Permuted discriminant function analysis revealed that rumbles contain sufficient acoustic information to predict the sex of a vocalizing individual. Features primarily related to the vocalizer's size, i.e. fundamental frequency variables and vocal tract resonant frequencies, differed significantly between the sexes. Yet, controlling for age and size effects, our results indicate that the pronounced sexual size dimorphism in African elephants is partly, but not exclusively, responsible for sexual differences in social rumbles. This provides a scientific foundation for future work investigating the perceptual and functional relevance of specific acoustic characteristics in African elephant vocal sexual communication.
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Affiliation(s)
- Anton Baotic
- Mammal Communication Lab, Department of Cognitive Biology, University of Vienna, Vienna, Austria
| | - Angela S. Stoeger
- Mammal Communication Lab, Department of Cognitive Biology, University of Vienna, Vienna, Austria
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Kimuyu DM, Veblen KE, Riginos C, Chira RM, Githaiga JM, Young TP. Influence of cattle on browsing and grazing wildlife varies with rainfall and presence of megaherbivores. Ecol Appl 2017; 27:786-798. [PMID: 27935669 DOI: 10.1002/eap.1482] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Revised: 10/25/2016] [Accepted: 11/15/2016] [Indexed: 06/06/2023]
Abstract
In many savanna ecosystems worldwide, livestock share the landscape and its resources with wildlife. The nature of interactions between livestock and wildlife is a subject of considerable interest and speculation, yet little controlled experimental research has been carried out. Since 1995, we have been manipulating the presence and absence of cattle and large mammalian herbivore wildlife in a Kenyan savanna in order to better understand how different herbivore guilds influence habitat use by specific wildlife species. Using dung counts as a relative assay of herbivore use of the different experimental plots, we found that cattle had a range of effects, mostly negative, on common mesoherbivore species, including both grazers and mixed feeders, but did not have significant effects on megaherbivores. The effect of cattle on most of the mesoherbivore species was contingent on both the presence of megaherbivores and rainfall. In the absence of megaherbivores, wild mesoherbivore dung density was 36% lower in plots that they shared with cattle than in plots they used exclusively, whereas in the presence of megaherbivores, wild mesoherbivore dung density was only 9% lower in plots shared with cattle than plots used exclusively. Cattle appeared to have a positive effect on habitat use by zebra (a grazer) and steinbuck (a browser) during wetter periods of the year but a negative effect during drier periods. Plots to which cattle had access had lower grass and forb cover than plots from which they were excluded, while plots to which megaherbivores had access had more grass cover but less forb cover. Grass cover was positively correlated with zebra and oryx dung density while forb cover was positively correlated with eland dung density. Overall these results suggest that interactions between livestock and wildlife are contingent on rainfall and herbivore assemblage and represent a more richly nuanced set of interactions than the longstanding assertion that cattle simply compete with (grazing) wildlife. Specifically, rainfall and megaherbivores seemed to moderate the negative effects of cattle on some mesoherbivore species. Even if cattle tend to reduce wildlife use of the landscape, managing simultaneously for livestock production (at moderate levels) and biodiversity conservation is possible.
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Affiliation(s)
- Duncan M Kimuyu
- Department of Natural Resources, Karatina University, Karatina, Kenya
- Mpala Research Centre, P.O. Box 555, Nanyuki, Kenya
| | - Kari E Veblen
- Mpala Research Centre, P.O. Box 555, Nanyuki, Kenya
- Department of Wildland Resources and Ecology Center, Utah State University, Logan, Utah, 84322, USA
| | - Corinna Riginos
- Mpala Research Centre, P.O. Box 555, Nanyuki, Kenya
- Department of Zoology and Physiology, University of Wyoming, Laramie, Wyoming, 82071, USA
| | - Robert M Chira
- School of Biological Sciences, University of Nairobi, Nairobi, Kenya
| | - John M Githaiga
- School of Biological Sciences, University of Nairobi, Nairobi, Kenya
| | - Truman P Young
- Mpala Research Centre, P.O. Box 555, Nanyuki, Kenya
- Department of Plant Sciences, University of California, Davis, California, 95616, USA
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45
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Albéric M, Dean MN, Gourrier A, Wagermaier W, Dunlop JWC, Staude A, Fratzl P, Reiche I. Relation between the Macroscopic Pattern of Elephant Ivory and Its Three-Dimensional Micro-Tubular Network. PLoS One 2017; 12:e0166671. [PMID: 28125603 PMCID: PMC5268646 DOI: 10.1371/journal.pone.0166671] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 10/26/2016] [Indexed: 11/18/2022] Open
Abstract
Macroscopic, periodic, dark and bright patterns are observed on sections of elephant tusk, in the dentin part (ivory). The motifs—also called Schreger pattern—vary depending on the orientation in the tusk: on sections perpendicular to the tusk axis, a checkerboard pattern is present whereas on sections longitudinal to it, alternating stripes are observed. This pattern has been used to identify elephant and mammoth ivory in archeological artifacts and informs on the continuous tissue growth mechanisms of tusk. However, its origin, assumed to be related to the 3D structure of empty microtubules surrounded by the ivory matrix has yet to be characterized unequivocally. Based on 2D observations of the ivory microtubules by means of a variety of imaging techniques of three different planes (transverse, longitudinal and tangential to the tusk axis), we show that the dark areas of the macroscopic pattern are due to tubules oblique to the surface whereas bright areas are related to tubules parallel to it. The different microstructures observed in the three planes as well as the 3D data obtained by SR-μCT analysis allow us to propose a 3D model of the microtubule network with helical tubules phase-shifted in the tangential direction. The phase shift is a combination of a continuous phase shift of π every 1 mm with a stepwise phase shift of π/2 every 500 μm. By using 3D modeling, we show how the 3D helical model better represents the experimental microstructure observed in 2D planes compared to previous models in the literature. This brings new information on the origin of the unique Schreger pattern of elephant ivory, crucial for better understanding how archaeological objects were processed and for opening new routes to rethink how biological materials are built.
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Affiliation(s)
- Marie Albéric
- Sorbonne Universités, Université Paris 6, Laboratoire d'Archéologie Moléculaire et Structurale, UMR 8220 CNRS – Université Pierre et Marie Curie, Paris, France
- Department of Biomaterials, Max-Planck-Institute of Colloids and Interfaces, Potsdam, Germany
| | - Mason N. Dean
- Department of Biomaterials, Max-Planck-Institute of Colloids and Interfaces, Potsdam, Germany
| | - Aurélien Gourrier
- Université Grenoble Alpes, Laboratoire Interdisciplinaire de Physique (LIPHY), Grenoble, France
- CNRS, LIPHY, Grenoble, France
- European Synchrotron Radiation Facility, Grenoble, France
| | - Wolfgang Wagermaier
- Department of Biomaterials, Max-Planck-Institute of Colloids and Interfaces, Potsdam, Germany
| | - John W. C. Dunlop
- Department of Biomaterials, Max-Planck-Institute of Colloids and Interfaces, Potsdam, Germany
| | - Andreas Staude
- Bundesanstalt für Materialforschung und –Prüfung (BAM), Berlin, Germany
| | - Peter Fratzl
- Department of Biomaterials, Max-Planck-Institute of Colloids and Interfaces, Potsdam, Germany
| | - Ina Reiche
- Sorbonne Universités, Université Paris 6, Laboratoire d'Archéologie Moléculaire et Structurale, UMR 8220 CNRS – Université Pierre et Marie Curie, Paris, France
- Rathgen-Forschungslabor, Staatliche Museen zu Berlin, Stiftung Preußischer Kulturbesitz, Berlin, Germany
- * E-mail: ,
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Charles GK, Porensky LM, Riginos C, Veblen KE, Young TP. Herbivore effects on productivity vary by guild: cattle increase mean productivity while wildlife reduce variability. Ecol Appl 2017; 27:143-155. [PMID: 28052507 DOI: 10.1002/eap.1422] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Revised: 06/22/2016] [Accepted: 08/01/2016] [Indexed: 05/28/2023]
Abstract
Wild herbivores and livestock share the majority of rangelands worldwide, yet few controlled experiments have addressed their individual, additive, and interactive impacts on ecosystem function. While ungulate herbivores generally reduce standing biomass, their effects on aboveground net primary production (ANPP) can vary by spatial and temporal context, intensity of herbivory, and herbivore identity and species richness. Some evidence indicates that moderate levels of herbivory can stimulate aboveground productivity, but few studies have explicitly tested the relationships among herbivore identity, grazing intensity, and ANPP. We used a long-term exclosure experiment to examine the effects of three groups of wild and domestic ungulate herbivores (megaherbivores, mesoherbivore wildlife, and cattle) on herbaceous productivity in an African savanna. Using both field measurements (productivity cages) and satellite imagery, we measured the effects of different herbivore guilds, separately and in different combinations, on herbaceous productivity across both space and time. Results from both productivity cage measurements and satellite normalized difference vegetation index (NDVI) demonstrated a positive relationship between mean productivity and total ungulate herbivore pressure, driven in particular by the presence of cattle. In contrast, we found that variation in herbaceous productivity across space and time was driven by the presence of wild herbivores (primarily mesoherbivore wildlife), which significantly reduced heterogeneity in ANPP and NDVI across both space and time. Our results indicate that replacing wildlife with cattle (at moderate densities) could lead to similarly productive but more heterogeneous herbaceous plant communities in rangelands.
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Affiliation(s)
- Grace K Charles
- Department of Plant Sciences, University of California, Davis, California, 95616, USA
- Mpala Research Centre, PO Box 555, Nanyuki, 10400, Kenya
| | - Lauren M Porensky
- Mpala Research Centre, PO Box 555, Nanyuki, 10400, Kenya
- Rangeland Resources Research Unit, USDA-ARS, 1701 Centre Avenue, Fort Collins, Colorado, 80526, USA
| | - Corinna Riginos
- Mpala Research Centre, PO Box 555, Nanyuki, 10400, Kenya
- Department of Zoology and Physiology, University of Wyoming, Laramie, Wyoming, 82071, USA
| | - Kari E Veblen
- Mpala Research Centre, PO Box 555, Nanyuki, 10400, Kenya
- Department of Wildland Resources and Ecology Center, Utah State University, Logan, Utah, 84322, USA
| | - Truman P Young
- Department of Plant Sciences, University of California, Davis, California, 95616, USA
- Mpala Research Centre, PO Box 555, Nanyuki, 10400, Kenya
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Cameron EZ, Ryan SJ. Welfare at Multiple Scales: Importance of Zoo Elephant Population Welfare in a World of Declining Wild Populations. PLoS One 2016; 11:e0158701. [PMID: 27415004 PMCID: PMC4945041 DOI: 10.1371/journal.pone.0158701] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Accepted: 06/20/2016] [Indexed: 11/18/2022] Open
Affiliation(s)
- Elissa Z. Cameron
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
- School of Biological Sciences, University of Tasmania, Hobart, Tasmania, Australia
- * E-mail:
| | - Sadie J. Ryan
- Department of Geography, University of Florida, Gainesville, Florida, United States of America
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Holdgate MR, Meehan CL, Hogan JN, Miller LJ, Rushen J, de Passillé AM, Soltis J, Andrews J, Shepherdson DJ. Recumbence Behavior in Zoo Elephants: Determination of Patterns and Frequency of Recumbent Rest and Associated Environmental and Social Factors. PLoS One 2016; 11:e0153301. [PMID: 27414809 PMCID: PMC4945027 DOI: 10.1371/journal.pone.0153301] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2015] [Accepted: 03/25/2016] [Indexed: 11/18/2022] Open
Abstract
Resting behaviors are an essential component of animal welfare but have received little attention in zoological research. African savanna elephant (Loxodonta africana) and Asian elephant (Elephas maximus) rest includes recumbent postures, but no large-scale investigation of African and Asian zoo elephant recumbence has been previously conducted. We used anklets equipped with accelerometers to measure recumbence in 72 adult female African (n = 44) and Asian (n = 28) elephants housed in 40 North American zoos. We collected 344 days of data and determined associations between recumbence and social, housing, management, and demographic factors. African elephants were recumbent less (2.1 hours/day, S.D. = 1.1) than Asian elephants (3.2 hours/day, S.D. = 1.5; P < 0.001). Nearly one-third of elephants were non-recumbent on at least one night, suggesting this is a common behavior. Multi-variable regression models for each species showed that substrate, space, and social variables had the strongest associations with recumbence. In the African model, elephants who spent any amount of time housed on all-hard substrate were recumbent 0.6 hours less per day than those who were never on all-hard substrate, and elephants who experienced an additional acre of outdoor space at night increased their recumbence by 0.48 hours per day. In the Asian model, elephants who spent any amount of time housed on all-soft substrate were recumbent 1.1 hours more per day more than those who were never on all-soft substrate, and elephants who spent any amount of time housed alone were recumbent 0.77 hours more per day than elephants who were never housed alone. Our results draw attention to the significant interspecific difference in the amount of recumbent rest and in the factors affecting recumbence; however, in both species, the influence of flooring substrate is notably important to recumbent rest, and by extension, zoo elephant welfare.
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Affiliation(s)
- Matthew R. Holdgate
- Department of Biology, Portland State University, Portland, Oregon, United States of America
- Conservation Research Division, Oregon Zoo, Portland, Oregon, United States of America
- * E-mail:
| | | | | | - Lance J. Miller
- Chicago Zoological Society—Brookfield Zoo, Brookfield, Illinois, United States of America
| | - Jeff Rushen
- Dairy Education and Research Centre, University of British Columbia, Agassiz, Canada
| | | | - Joseph Soltis
- Department of Education & Science, Disney’s Animal Kingdom, Lake Buena Vista, Florida, United States of America
| | - Jeff Andrews
- Zoological Operations, Busch Gardens, Tampa, Florida, United States of America
| | - David J. Shepherdson
- Department of Biology, Portland State University, Portland, Oregon, United States of America
- Conservation Research Division, Oregon Zoo, Portland, Oregon, United States of America
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49
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Morfeld KA, Meehan CL, Hogan JN, Brown JL. Assessment of Body Condition in African (Loxodonta africana) and Asian (Elephas maximus) Elephants in North American Zoos and Management Practices Associated with High Body Condition Scores. PLoS One 2016; 11:e0155146. [PMID: 27415629 PMCID: PMC4944958 DOI: 10.1371/journal.pone.0155146] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Accepted: 04/23/2016] [Indexed: 12/20/2022] Open
Abstract
Obesity has a negative effect on health and welfare of many species, and has been speculated to be a problem for zoo elephants. To address this concern, we assessed the body condition of 240 elephants housed in North American zoos based on a set of standardized photographs using a 5-point Body Condition Score index (1 = thinnest; 5 = fattest). A multi-variable regression analysis was then used to determine how demographic, management, housing, and social factors were associated with an elevated body condition score in 132 African (Loxodonta africana) and 108 Asian (Elephas maximus) elephants. The highest BCS of 5, suggestive of obesity, was observed in 34% of zoo elephants. In both species, the majority of elephants had elevated BCS, with 74% in the BCS 4 (40%) and 5 (34%) categories. Only 22% of elephants had BCS 3, and less than 5% of the population was assigned the lowest BCS categories (BCS 1 and 2). The strongest multi-variable model demonstrated that staff-directed walking exercise of 14 hours or more per week and highly unpredictable feeding schedules were associated with decreased risk of BCS 4 or 5, while increased diversity in feeding methods and being female was associated with increased risk of BCS 4 or 5. Our data suggest that high body condition is prevalent among North American zoo elephants, and management strategies that help prevent and mitigate obesity may lead to improvements in welfare of zoo elephants.
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Affiliation(s)
- Kari A. Morfeld
- Lincoln Children’s Zoo, Lincoln, Nebraska, United States of America
- Center for Species Survival, Smithsonian Conservation Biology Institute, Smithsonian National Zoological Park, Front Royal, Virginia, United States of America
| | | | | | - Janine L. Brown
- Center for Species Survival, Smithsonian Conservation Biology Institute, Smithsonian National Zoological Park, Front Royal, Virginia, United States of America
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Holdgate MR, Meehan CL, Hogan JN, Miller LJ, Soltis J, Andrews J, Shepherdson DJ. Walking Behavior of Zoo Elephants: Associations between GPS-Measured Daily Walking Distances and Environmental Factors, Social Factors, and Welfare Indicators. PLoS One 2016; 11:e0150331. [PMID: 27414411 PMCID: PMC4944962 DOI: 10.1371/journal.pone.0150331] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Accepted: 02/11/2016] [Indexed: 11/18/2022] Open
Abstract
Research with humans and other animals suggests that walking benefits physical health. Perhaps because these links have been demonstrated in other species, it has been suggested that walking is important to elephant welfare, and that zoo elephant exhibits should be designed to allow for more walking. Our study is the first to address this suggestion empirically by measuring the mean daily walking distance of elephants in North American zoos, determining the factors that are associated with variations in walking distance, and testing for associations between walking and welfare indicators. We used anklets equipped with GPS data loggers to measure outdoor daily walking distance in 56 adult female African (n = 33) and Asian (n = 23) elephants housed in 30 North American zoos. We collected 259 days of data and determined associations between distance walked and social, housing, management, and demographic factors. Elephants walked an average of 5.3 km/day with no significant difference between species. In our multivariable model, more diverse feeding regimens were correlated with increased walking, and elephants who were fed on a temporally unpredictable feeding schedule walked 1.29 km/day more than elephants fed on a predictable schedule. Distance walked was also positively correlated with an increase in the number of social groupings and negatively correlated with age. We found a small but significant negative correlation between distance walked and nighttime Space Experience, but no other associations between walking distances and exhibit size were found. Finally, distance walked was not related to health or behavioral outcomes including foot health, joint health, body condition, and the performance of stereotypic behavior, suggesting that more research is necessary to determine explicitly how differences in walking may impact elephant welfare.
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Affiliation(s)
- Matthew R. Holdgate
- Department of Biology, Portland State University, Portland, Oregon, United States of America
- Conservation Research Division, Oregon Zoo, Portland, Oregon, United States of America
- * E-mail:
| | | | | | - Lance J. Miller
- Chicago Zoological Society—Brookfield Zoo, Brookfield, Illinois, United States of America
| | - Joseph Soltis
- Department of Education & Science, Disney’s Animal Kingdom, Lake Buena Vista, Florida, United States of America
| | - Jeff Andrews
- Zoological Operations, Busch Gardens, Tampa, Florida, United States of America
| | - David J. Shepherdson
- Department of Biology, Portland State University, Portland, Oregon, United States of America
- Conservation Research Division, Oregon Zoo, Portland, Oregon, United States of America
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