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Majelantle TL, Ganswindt A, Hart DW, Hagenah N, Ganswindt SB, Bennett NC. The dissection of a despotic society: exploration, dominance and hormonal traits. Proc Biol Sci 2024; 291:20240371. [PMID: 38714210 PMCID: PMC11095815 DOI: 10.1098/rspb.2024.0371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 03/27/2024] [Accepted: 03/27/2024] [Indexed: 05/09/2024] Open
Abstract
Naked mole-rats (Heterocephalus glaber) live in large colonies with one breeding female (queen), one to three breeding males (BMs) and the remainder are non-reproductive subordinates. The animals have a linear dominance rank with the breeders at the top of the hierarchy. We investigated how dominance rank in naked mole-rats differs with exploration (the propensity to explore a novel environment) and related endocrine markers. Exploration behaviour, faecal progestagen metabolite (fPM), faecal glucocorticoid metabolite (fGCM), faecal androgen metabolite (fAM) and plasma prolactin concentrations were quantified in breeding, high-, middle- and low-ranked females and males from five naked mole-rat colonies. There were no significant differences between the dominance rank and exploration behaviour. Interestingly, the queens and high-ranking females had higher fGCM and fAM concentrations compared with middle- and low-ranked females. The queens had significantly higher fPM concentrations than all other ranked females, since they are responsible for procreation. In the males, the BMs had higher fGCM concentrations compared with high- and low-ranked males. In addition, BMs and middle-ranking males had overall higher prolactin levels than all other ranked males, which could be linked to cooperative care. Overall, the results suggest that physiological reproductive suppression is linked to high dominance rank.
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Affiliation(s)
- Tshepiso Lesedi Majelantle
- Department of Zoology and Entomology, Mammal Research Institute, University of Pretoria, Pretoria, 400364, South Africa
| | - Andre Ganswindt
- Department of Zoology and Entomology, Mammal Research Institute, University of Pretoria, Pretoria, 400364, South Africa
| | - Daniel William Hart
- Department of Zoology and Entomology, Mammal Research Institute, University of Pretoria, Pretoria, 400364, South Africa
| | - Nicole Hagenah
- Department of Zoology and Entomology, Mammal Research Institute, University of Pretoria, Pretoria, 400364, South Africa
| | - Stefanie Birgit Ganswindt
- Department of Zoology and Entomology, Mammal Research Institute, University of Pretoria, Pretoria, 400364, South Africa
| | - Nigel Charles Bennett
- Department of Zoology and Entomology, Mammal Research Institute, University of Pretoria, Pretoria, 400364, South Africa
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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] [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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Bertrand DA, Berman CM, Heistermann M, Agil M, Sutiah U, Engelhardt A. Effects of Tourist and Researcher Presence on Fecal Glucocorticoid Metabolite Levels in Wild, Habituated Sulawesi Crested Macaques ( Macaca nigra). Animals (Basel) 2023; 13:2842. [PMID: 37760243 PMCID: PMC10525950 DOI: 10.3390/ani13182842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 08/28/2023] [Accepted: 08/29/2023] [Indexed: 09/29/2023] Open
Abstract
Ecotourism managers and researchers often assume that apparently habituated primate groups no longer experience adverse consequences of prolonged exposure to tourists or researchers. We examined the effects of tourists and researchers on fecal glucocorticoid metabolite output (FGCM) in three critically endangered, wild crested macaque (Macaca nigra) groups in Tangkoko Nature Reserve, Sulawesi, Indonesia. We assayed FGCM from 456 fecal samples collected from thirty-three adults. Tourists can walk through and among macaque groups freely. Hence, we examined the possible effects of tourists both (1) in the reserve when away and not interacting with the study groups and (2) when they were present within the macaque groups. Generalized Linear Mixed Model (GLMM) analysis indicated that when tourists were present in the forest, but not directly among the macaques, FGCM levels in the macaque tourism groups were higher in months with more tourists. When tourists were among the macaque groups, some female macaques experienced rises and subsequent postexposure decreases in FGCM levels, consistent with predictions for acute stress. Male FGCM levels increased with tourist numbers within the group. Nevertheless, they were not significantly different from levels during undisturbed or postexposure conditions. FGCM responses related to researchers in groups varied by group, sex, and tourist presence. However, the temporal patterning of FGCM responses showed little evidence of chronic stress from tourism at this site.
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Affiliation(s)
| | - Carol M. Berman
- Department of Anthropology, University at Buffalo, Buffalo, NY 14261, USA
- Evolution, Ecology, & Behavior Program, Department of Environment and Sustainability, University at Buffalo, Buffalo, NY 14260, USA
| | - Michael Heistermann
- German Primate Centre, Endocrinology Laboratory, Leibniz Institute for Primate Research, 37077 Goettingen, Germany
| | - Muhammad Agil
- Faculty of Veterinary Medicine, Bogor Agricultural University, Bogor 16680, Indonesia
| | - Uni Sutiah
- Faculty of Veterinary Medicine, Bogor Agricultural University, Bogor 16680, Indonesia
| | - Antje Engelhardt
- School of Natural Sciences and Psychology, Liverpool John Moores University, Liverpool L3 3AF, UK
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Behringer V, Heistermann M, Malaivijitnond S, Schülke O, Ostner J. Developmental and environmental modulation of fecal thyroid hormone levels in wild Assamese macaques (Macaca assamensis). Am J Primatol 2023; 85:e23530. [PMID: 37365835 DOI: 10.1002/ajp.23530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 06/09/2023] [Accepted: 06/18/2023] [Indexed: 06/28/2023]
Abstract
Thyroid hormones are key modulators of development, as well as mediators of environmental conditions, by regulating developmental processes and metabolism in primates. Hormone measurement in noninvasively collected samples, that is, feces and urine, is a valuable tool for studying the endocrine function of wildlife, and recent studies have demonstrated the feasibility of measuring thyroid hormones in fecal samples of zoo-housed and wild nonhuman primates. Our study aimed to (i) validate the measurement of immunoreactive fecal total triiodothyronine (IF-T3) in wild Assamese macaques (Macaca assamensis) and (ii) to investigate its developmental changes and its response to environmental changes, including stress responses, in immature individuals. Fecal samples and environmental parameters were collected from individuals of three social groups of wild Assamese macaques living at Phu Khieo Wildlife Sanctuary, Northeastern Thailand. Our study confirmed the methodological feasibility and biological validity of measuring IF-T3 in this population. Specifically, the biological validation demonstrated higher IF-T3 levels in immatures compared to adults, and higher levels in females during late gestation compared to the preconception stage. Our analysis of IF-T3 levels in developing immature macaques revealed a significant increase with age. Furthermore, we found a positive association between IF-T3 and immunoreactive fecal glucocorticoid levels, an indicator of the physiological stress response. Neither minimum temperature nor fruit abundance predicted variation in IF-T3 levels in the immatures. Our findings indicate the possibility for differing effects of climatic factors and food availability on thyroid hormone level changes in immature versus adult animals and in wild compared to experimental conditions. Overall, our study provides the basis for further investigations into the role of thyroid hormones in shaping species-specific traits, growth, and overall primate development.
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Affiliation(s)
- Verena Behringer
- Endocrinology Laboratory, German Primate Center, Leibniz Institute for Primate Research, Göttingen, Germany
- Leibniz ScienceCampus Primate Cognition, German Primate Center, Leibniz Institute for Primate Research, Göttingen, Germany
| | - Michael Heistermann
- Endocrinology Laboratory, German Primate Center, Leibniz Institute for Primate Research, Göttingen, Germany
| | - Suchinda Malaivijitnond
- Department of Biology, Faculty of Science, Chulalongkorn University, Bangkok, Thailand
- National Primate Research Center of Thailand, Chulalongkorn University, Saraburi, Thailand
| | - Oliver Schülke
- Leibniz ScienceCampus Primate Cognition, German Primate Center, Leibniz Institute for Primate Research, Göttingen, Germany
- Behavioral Ecology Department, University of Goettingen, Göttingen, Germany
- Primate Social Evolution Group, German Primate Center, Leibniz Institute for Primate Research, Göttingen, Germany
| | - Julia Ostner
- Leibniz ScienceCampus Primate Cognition, German Primate Center, Leibniz Institute for Primate Research, Göttingen, Germany
- Behavioral Ecology Department, University of Goettingen, Göttingen, Germany
- Primate Social Evolution Group, German Primate Center, Leibniz Institute for Primate Research, Göttingen, Germany
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Thierry B, Rebout N, Heistermann M. Hormonal responses to mating competition in male Tonkean macaques. Horm Behav 2023; 154:105395. [PMID: 37390781 DOI: 10.1016/j.yhbeh.2023.105395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 03/30/2023] [Accepted: 06/17/2023] [Indexed: 07/02/2023]
Abstract
Glucocorticoid and androgen hormones play a prominent role in male reproductive effort. Their production usually increases in non-human primates during mating competition, which may include rivalry for access to receptive females, struggles for high dominance rank, or social pressure on low-ranking individuals. It is generally assumed that glucocorticoids and androgens are associated with mating challenges rather than dominance status, but the involvement of multiple factors makes it difficult to disentangle the two. In this regard, Tonkean macaques provide a suitable model because they are characterized by relaxed dominance and year-round breeding, meaning that there is typically no more than one receptive female in a group, and thus first-ranking males can easily monopolize her. We studied two captive groups of Tonkean macaques over an 80-month period, recording the reproductive status of females, collecting urine from males and sampling behaviors in both sexes. Male urinary hormone concentrations could be affected by increased competition caused by the mating period, the number of males and the degree of female attractiveness. The highest increases in androgens were recorded in males performing female mate-guarding. Despite the importance of dominance status in determining which males can mate, we found no significant effect of male rank on glucocorticoids and only a marginal effect on androgens during mate-guarding. Both types of hormones were more directly involved in the mating effort of males than in their dominance status. Our results show that their function can be understood in light of the particular competitive needs generated by the species-specific social system.
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Affiliation(s)
- Bernard Thierry
- Laboratoire de Psychologie Sociale et Cognitive, CNRS, Université Clermont Auvergne, Clermont-Ferrand, France.
| | - Nancy Rebout
- UMR Herbivores, INRAE, VetAgro Sup, Université Clermont Auvergne, Clermont-Ferrand, France
| | - Michael Heistermann
- Endocrinology Laboratory, German Primate Center, Leibniz Institute for Primate Research, Göttingen, Germany
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Lacomme L, Guerbois C, Fritz H, Ganswindt A, Rey B. Validation of a field-friendly faeces drying and storage method for quantifying faecal glucocorticoid metabolites in African elephants (Loxodonta africana) opens up new perspectives for conservationists. CONSERVATION PHYSIOLOGY 2023; 11:coad053. [PMID: 37538993 PMCID: PMC10395557 DOI: 10.1093/conphys/coad053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 06/15/2023] [Accepted: 07/24/2023] [Indexed: 08/05/2023]
Abstract
Faecal glucocorticoid metabolites (fGCMs) are a relevant means of non-invasively assessing adrenocortical activity and thus, a key physiological stress response in wildlife populations. However, the widespread use of fGCMs as a stress-related biomarker in conservation biology is often hampered by the logistical challenge of storing collected faecal material frozen until it reaches the laboratory for analysis. Although alternative approaches to minimize potential alteration of fGCM composition post-defecation have been recently identified, there is to our knowledge, no satisfactory alternative method established for the preservation of elephant dung. In this study, we validated a field-friendly protocol for dehydrating African elephant faeces samples using a food dehydrator with desiccant and investigated the stability of fGCM concentrations in the dehydrated faeces when stored at ambient temperature. We collected 40 faecal samples from African elephants and compared fGCM concentrations of freeze-dried and dehydrated sample sub-sets. Samples dried in the field showed a slight but significant overall -6% reduction in fGCM concentration compared with frozen control samples. However, fGCM concentrations following field dehydration protocol match those of control samples with high accuracy, as evidenced by the low bias and strong coefficient of determination between the two approaches (R2 = 0.88). In addition, over nearly 2 months, storage time at ambient temperature of the dehydrated samples had no effect on the fGCM concentrations compared with those measured in the control samples (F-statistic = 1.82; P = 0.18). Dehydrating the samples in the field thus provides an easy and cost-effective alternative to freezing, especially when working in remote areas with unstable electrical supply. Our results encourage the widespread use of fGCMs by conservationists as non-invasive means of steroid monitoring of African elephants in the current context of a general increase in wildlife welfare research. Future studies are needed to extend the use of this protocol to other species and to other steroid classes.
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Affiliation(s)
- Laura Lacomme
- Corresponding author: Biometry and Evolutionary Biology laboratory (LBBE), French National Centre for Scientific Research (CNRS), Unit 5558, University of Lyon 1, 43 Bd du 11 Novembre 1918, 69622 Villeurbanne cedex, France.
| | - Chloé Guerbois
- Sustainability Research Unit, Nelson Mandela University, George Campus, Madiba Drive, George 6529, South Africa
| | - Hervé Fritz
- Sustainability Research Unit, Nelson Mandela University, George Campus, Madiba Drive, George 6529, South Africa
| | - André Ganswindt
- Mammal Research Institute (MRI), Department of Zoology and Entomology, Faculty of Natural and Agricultural Sciences, University of Pretoria, Hatfield Campus, Pretoria 0028, South Africa
| | - Benjamin Rey
- Biometry and Evolutionary Biology laboratory (LBBE), French National Centre for Scientific Research (CNRS),Unit 5558, University of Lyon 1, 43 Bd du 11 novembre 1918, 69622 Villeurbanne cedex, France
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Flacke GL, Penfold LM, Schwarzenberger F, Martin GB, Rosales-Nieto CA, C J Paris M. Non-invasive Assessment of Fecal Glucocorticoid and Androgen Metabolites in the Pygmy Hippopotamus (Choeropsis liberiensis). Gen Comp Endocrinol 2023:114338. [PMID: 37348682 DOI: 10.1016/j.ygcen.2023.114338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Revised: 05/21/2023] [Accepted: 06/15/2023] [Indexed: 06/24/2023]
Abstract
The pygmy hippopotamus (Choeropsis liberiensis) is an endangered species endemic to the Upper Guinea Forest ecosystem in West Africa. We have limited information concerning the species' reproduction and well-being under managed care. We therefore developed non-invasive methods for characterizing gonadal androgen and adrenal hormone profiles in pygmy hippos using fecal samples collected from 12 males and 12 females housed in North American zoological institutions. We aimed to: 1) identify and validate enzyme immunoassays (EIAs) for measuring metabolites of corticosteroids and testosterone in feces; and 2) test whether gonadal activity is correlated with previous breeding history, season or type of housing. For glucocorticoids, several EIAs for measuring metabolites were investigated. A group-specific EIA exhibiting cross-reactivity with 11,17-dioxoandrostane (DOA) metabolites of cortisol most clearly reflected adrenocortical activity in response to ACTH1 challenge in both males and females. However, day-to-day concentrations of this metabolite in the feces of pygmy hippos that did not undergo ACTH challenge were near the detection limits of the assay, making this EIA impractical for assessing glucocorticoid activity in this species. Another group-specific EIA, exhibiting cross-reactivity with 5α-pregnane-3β,11β,21-triol-20-one, produced biologically relevant data and evidence of an appropriate response to pharmacological challenge with exogenous ACTH. The testosterone metabolite assay C196 (Arbor Assays, Ann Arbor, Michigan, USA) also produced biologically coherent data: adult males exhibited the highest mean androgen metabolite concentrations (477 ng/g), followed by adult females (259 ng/g) and juvenile males (160 ng/g). Proven breeding males had higher, but not significantly different, mean concentrations (472 ng/g) to unproven males (352 ng/g; P = 0.400). Similarly, adult males housed outdoors year-round in subtropical climates exhibited higher, but not statistically different mean concentrations (554 ng/g) to males in temperate climates that were housed indoors at least part of the year (412 ng/g; P = 0.208). There were, however, significant differences in mean concentrations among seasons for adult males, with higher values in spring (546 ng/g) and summer (542 ng/g) than in autumn (426 ng/g) and winter (388 ng/g, P = 0.003). In conclusion, we identified EIAs for the measurement of fecal metabolites of androgens and glucocorticoids that can be used for further studies to monitor gonadal activity in male pygmy hippos and adrenocortical activity in both sexes. We also identified a seasonal trend in male gonadal activity in this species under managed care in North America. Finally, our findings highlight an important consideration when using non-invasive methods for evaluating fecal cortisol metabolites: ACTH used for pharmacological validation of an EIA does not necessarily equate to biological relevance.
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Affiliation(s)
- Gabriella L Flacke
- UWA School of Agriculture and Environment, University of Western Australia, 35 Stirling Highway, Crawley 6009, Australia; Department of Animal Health, Zoo Miami, 12400 SW 152(nd) Street, Miami, Florida 33177, USA.
| | - Linda M Penfold
- South East Zoo Alliance for Reproduction & Conservation, 581705 White Oak Road, Yulee, FL 32097, USA.
| | - Franz Schwarzenberger
- Department of Biomedical Sciences - Endocrinology, University of Veterinary Medicine (Vetmeduni Vienna), Veterinärplatz 1, 1210 Vienna, Austria.
| | - Graeme B Martin
- UWA School of Agriculture and Environment, University of Western Australia, 35 Stirling Highway, Crawley 6009, Australia
| | - César A Rosales-Nieto
- Department of Agricultural Sciences, Texas State University, 601 University Drive, San Marcos, Texas 78666, USA.
| | - Monique C J Paris
- Institute for Breeding Rare and Endangered African Mammals (IBREAM), Edinburgh EH3 6AT, United Kingdom; Mammal Research Institute and Centre for Neuroendocrinology, University of Pretoria, Department of Zoology and Entomology, Pretoria 0084, South Africa; College of Public Health, Veterinary and Medical Sciences, James Cook University, Townsville 4811, Australia.
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LaDue CA, Hunt KE, Kiso WK, Freeman EW. Hormonal variation and temporal dynamics of musth in Asian elephants ( Elephas maximus) are associated with age, body condition and the social environment. CONSERVATION PHYSIOLOGY 2023; 11:coad019. [PMID: 38026805 PMCID: PMC10660383 DOI: 10.1093/conphys/coad019] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 03/23/2023] [Accepted: 03/27/2023] [Indexed: 12/01/2023]
Abstract
The sustainability of endangered Asian elephants in human care is threatened in part by low breeding success and concerns over individual animal wellbeing. Male elephants have received less research attention compared to females, yet males deserve special consideration due to their unique reproductive biology (particularly the sexual state of "musth") and the complex interaction of physiological, environmental, and social pressures they face. We measured fecal androgen metabolites (FAMs), fecal glucocorticoid metabolites (FGMs), and fecal triiodothyronine metabolites (FT3s) collected weekly over approximately 12 months from 26 male Asian elephants housed in zoos across the US, hypothesizing that FAM, FGM, and FT3 concentrations would be associated with temporal correlates of musth and would vary further with intrinsic (musth status, age, body condition) and extrinsic (social environment) factors. The duration of each musth episode was positively associated with exposure to male conspecifics and negatively associated with body condition. Further, elevated FAM concentrations were associated with social exposure, age, and body condition, and FGM concentrations also varied with age and body condition. FT3 concentrations were not associated with any factor we measured. We also identified periods of lower FAM concentration than confirmed musth episodes (but still higher than baseline FAM concentrations) that we termed "elevated FAM episodes." The durations of these episodes were negatively correlated with exposure to other male elephants. Together, these results provide evidence that hormone profiles (including those that are predicted to change around musth) vary significantly between male Asian elephants in a way that may be attributed to intrinsic and extrinsic factors. Studies like these serve to enhance the sustainability of ex-situ populations by providing wildlife managers with information to enhance the health, welfare, and reproduction of threatened species like Asian elephants.
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Affiliation(s)
- Chase A LaDue
- Department of Environmental Science and Policy, 4400 University Drive, MSN 5F2, George Mason University, Fairfax, VA 22030, USA
- Oklahoma City Zoo and Botanical Garden, 2000 Remington Place, Oklahoma City, OK 73111, USA
| | - Kathleen E Hunt
- Department of Biology, George Mason University, 10900 University Boulevard, Manassas, VA 20110, USA
- Smithsonian-Mason School of Conservation, 1500 Remount Road, Front Royal, VA 22630, USA
| | - Wendy K Kiso
- White Oak Conservation Foundation, 581705 White Oak Road, Yulee, FL 32097, USA
- Colossal Biosciences, 3309 Elm Street, Dallas, TX 75226, USA
| | - Elizabeth W Freeman
- School of Integrative Studies, 4400 University Drive, MSN 5D3, George Mason University, Fairfax, VA 22030, USA
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Alba AC, Wheaton CJ, Weibel CJ, Hicks P, Richards B, Lyon CEM, Ferrie GM. Using behavior and genital swellings to monitor social dynamics and track reproductive cycling in zoo-housed lion-tailed macaques (Macaca silenus). Am J Primatol 2023; 85:e23432. [PMID: 36138540 DOI: 10.1002/ajp.23432] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 08/19/2022] [Accepted: 09/05/2022] [Indexed: 11/09/2022]
Abstract
Though lion-tailed macaques are managed ex situ as an assurance population, little information is available on the relationship between behavior and reproductive physiology to ensure successful management and evaluate welfare. To facilitate social and reproductive management in a group of one male and three female lion-tailed macaques at Disney's Animal Kingdom®, we observed behaviors associated with dominance and reproduction, rated genital swellings, recorded menses, tracked ovarian cycles as determined by measurement of fecal immunoreactive progesterone (P4) and estradiol (E2), and monitored fecal cortisol (CORT). We analyzed the dominance hierarchy of females, compared hormone patterns of ovarian cycles with genital swellings and copulations relative to menses, and tested for correlations between hormones and behavior. The strength of the dominance hierarchy indicated moderate linearity, but relaxed after the dominant female received anxiolytic medications to reduce intraspecific aggression. Fecal P4 and E2 patterns revealed ovarian cycle lengths averaging 29.7 ± 0.8 days. The timing of single-day E2 peaks varied between and within females' cycles. However, on average, E2 peaks occurred 6-10 days after the first day of menses, with maximum genital swellings and copulations occurring slightly thereafter in uncontracepted females. Female-to-female aggression and sexual behaviors with the male were related to ovarian cycle phase, but correlations between behaviors and hormones varied between females. Initiated aggression was positively correlated with E2 in the dominant and mid-ranked females, while aggression received was positively correlated with P4 or negatively correlated with E2 in the mid-ranked and subordinate females. In one uncontracepted female, sexual behaviors with the male were negatively correlated to P4. CORT was positively correlated to aggression in the dominant and mid-ranked females and negatively correlated to grooming in the subordinate female. Results indicate observations of visual and behavioral cues can be used to track ovarian cycles and evaluate social dynamics and welfare in zoo-housed lion-tailed macaques.
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Affiliation(s)
- Andrew C Alba
- Animals, Science and Environment, Disney's Animal Kingdom®, Lake Buena Vista, Florida, USA
| | - Catharine J Wheaton
- Animals, Science and Environment, Disney's Animal Kingdom®, Lake Buena Vista, Florida, USA
| | - Chelsea J Weibel
- Animals, Science and Environment, Disney's Animal Kingdom®, Lake Buena Vista, Florida, USA
| | - Pilar Hicks
- Animals, Science and Environment, Disney's Animal Kingdom®, Lake Buena Vista, Florida, USA
| | - Beth Richards
- Animals, Science and Environment, Disney's Animal Kingdom®, Lake Buena Vista, Florida, USA
| | - Cassandra E M Lyon
- Animals, Science and Environment, Disney's Animal Kingdom®, Lake Buena Vista, Florida, USA
| | - Gina M Ferrie
- Animals, Science and Environment, Disney's Animal Kingdom®, Lake Buena Vista, Florida, USA
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Sen S, Carrera SC, Heistermann M, Potter CB, Baniel A, DeLacey PM, Petrullo L, Lu A, Beehner JC. Social correlates of androgen levels and dispersal age in juvenile male geladas. Horm Behav 2022; 146:105264. [PMID: 36155910 DOI: 10.1016/j.yhbeh.2022.105264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 09/06/2022] [Accepted: 09/09/2022] [Indexed: 11/23/2022]
Abstract
Androgens offer a window into the timing of important male life history events such as maturation. However, when males are the dispersing sex, piecing together normative androgen profiles across development is challenging because dispersing males are difficult to track. Here, we examined the conditions that may be associated with male androgen status (via fecal androgen metabolites, fAMs) and age at dispersal in wild male geladas (Theropithecus gelada). Gelada male life histories are highly variable - dispersal may occur before sexual maturation, dispersal itself can be immediate or drawn out, and, due to their multi-leveled society, social conditions affecting dispersal can vary for juveniles living in different reproductive units within the same band. Using longitudinal data from known natal males, we examined how androgen levels and age at dispersal were associated with: (1) access to maternal resources (i.e., maternal rank, birth of a younger sibling, experiencing maternal loss), and (2) access to male peers (i.e., number of similar-aged males in their unit). We found that androgens were significantly lower in males with high-ranking mothers (in males >2.5 years of age; infant androgens were unrelated) and that having more male peers in their social group and larger groups overall predicted an earlier age at dispersal. Moreover, dispersal in geladas was not preceded or followed by a surge in androgen levels. Taken together, results suggest that social environments can cause individual variation in androgens and dispersal age. Whether this variation leads to differences in male fitness in later life remains to be determined.
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Affiliation(s)
- Sharmi Sen
- Department of Anthropology, University of Michigan, Ann Arbor, MI 48109-1107, USA.
| | - Sofia C Carrera
- Department of Psychology, University of Michigan, Ann Arbor, MI 48109-1107, USA
| | - Michael Heistermann
- Endocrinology Laboratory, German Primate Center, Leibniz Institute for Primate Research, 37077 Göttingen, Germany
| | - Caitlin Barale Potter
- Cedar Creek Ecosystem Science Reserve, University of Minnesota, St. Paul, MN 55108, USA
| | - Alice Baniel
- Center for Evolution and Medicine, Arizona State University, Tempe, AZ 85281, USA; School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA
| | - Patricia M DeLacey
- Department of Psychology, University of Michigan, Ann Arbor, MI 48109-1107, USA
| | - Lauren Petrullo
- Department of Psychology, University of Michigan, Ann Arbor, MI 48109-1107, USA
| | - Amy Lu
- Department of Anthropology, Stony Brook University, Stony Brook, NY 11794-4364, USA
| | - Jacinta C Beehner
- Department of Anthropology, University of Michigan, Ann Arbor, MI 48109-1107, USA; Department of Psychology, University of Michigan, Ann Arbor, MI 48109-1107, USA
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11
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Can stress and anxiety be assessed in African elephants (Loxodonta africana) using self-directed behaviour? Appl Anim Behav Sci 2022. [DOI: 10.1016/j.applanim.2022.105746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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12
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Kamgang VW, Bennett NC, van der Goot AC, Majelantle TL, Ganswindt A. Patterns of faecal glucocorticoid metabolite levels in captive roan antelope (Hippotragus equinus) in relation to reproductive status and season. Gen Comp Endocrinol 2022; 325:114052. [PMID: 35568230 DOI: 10.1016/j.ygcen.2022.114052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Revised: 02/19/2022] [Accepted: 05/07/2022] [Indexed: 11/18/2022]
Abstract
Populations of roan antelope (Hippotragus equinus) in southern Africa have experienced a drastic decline over the past few decades and this situation has led to the development of intensive breeding programmes to support conservation efforts. However, little is known about related welfare aspects, including stress-related physiological biomarkers. The present study set out to establish a non-invasive method to monitor faecal glucocorticoid metabolite (fGCM) concentrations as a measure of stress and determine fGCM concentrations in relation to male reproductive activity and female reproductive status in the roan antelope. An adrenocorticotrophic hormone challenge was performed using two adult roan antelope (one male and one female) at Lapalala Wilderness Nature Reserve, South Africa, to determine the suitability of five enzyme immunoassays (EIA) for monitoring adrenocortical function in roan antelope. An 11-oxoaetiocholanolone I EIA detecting 11,17 dioxoandrostanes performed best showing 17-20 folds increases in fGCM concentrations after 12 h-17 h post-injection. The identified EIA was then used to monitor fGCM concentrations during active and non-active reproductive periods in males (n = 3), and during periods of cyclicity, gestation, and postpartum in females (n = 10). Males showed an overall 80% increase in fGCM concentrations when reproductively active and females showed a progressively significant increase in fGCM levels throughout pregnancy, with overall fGCM concentrations being 1.5 to 2.6-fold higher than the respective fGCM concentrations during periods of postpartum and cyclicity, respectively. Furthermore, fGCM concentrations remained above baseline for up to 21 days post-partum. A correlation between ecological parameters (rainfall and temperature) and fGCM concentrations revealed elevated fGCM concentrations during the dry season for males, but not females. The non-invasive method validated in this study provides a valuable tool to quantify stress-related biomarkers in roan antelope, and findings can be used to support management decisions in conservation breeding facilities.
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Affiliation(s)
- Vanessa W Kamgang
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Hatfield 0028, South Africa.
| | - Nigel C Bennett
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Hatfield 0028, South Africa
| | - Annemieke C van der Goot
- Lapalala Wilderness Nature Reserve, Vaalwater 0530, South Africa; Melkrivier Wildlife Veterinary Services, Melkrivier, Vaalwater 0530, South Africa
| | - Tshepiso L Majelantle
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Hatfield 0028, South Africa
| | - Andre Ganswindt
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Hatfield 0028, South Africa
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13
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Characterization of Longitudinal Testosterone, Cortisol, and Musth in Male Asian Elephants ( Elephas maximus), Effects of Aging, and Adrenal Responses to Social Changes and Health Events. Animals (Basel) 2022; 12:ani12101332. [PMID: 35625178 PMCID: PMC9137588 DOI: 10.3390/ani12101332] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 05/04/2022] [Accepted: 05/19/2022] [Indexed: 01/09/2023] Open
Abstract
Simple Summary The conservation of endangered species and sustainability of managed populations requires good health and welfare of individuals. Male elephants experience a biological phenomenon called “musth”, characterized by a suite of physiological and behavioral changes which serve to facilitate copulation between the sexes, but can also pose unique challenges under human care. This study characterized longitudinal patterns of circulating testosterone and cortisol in relation to musth in four adult Asian elephant bulls and assessed age-related effects on musth activity and adrenal responses to social changes and clinical health events. All bulls exhibited regular annual musth cycles, and there was no clear evidence of chronically elevated cortisol secretion outside of musth. Circulating cortisol covaried positively with testosterone and musth, highlighting intrinsic patterns that should be considered when evaluating the impact of changes on adrenal glucocorticoid activity. Testosterone decreased with age in sexually mature bulls, whereas age-related changes in cortisol varied across individuals, with the three older bulls showing the greatest rate of change during musth. Changes in cortisol were associated with treatment for Mycobacterium tuberculosis in two bulls, but not with activation of disease. In contrast to physiological factors, there was no evidence that social changes involving male herdmates impacted adrenal glucocorticoid activity in the short term. This study highlights the importance of longitudinal hormone monitoring to track changes in physiological function and identify factors that may influence welfare, which is important for making more informed decisions on how to manage male elephants under varying degrees of human care. Abstract The conservation of endangered species and sustainability of managed populations requires considerations to ensure the health and welfare of individuals. Male elephants experience a biological phenomenon called “musth”, which is characterized by increased testosterone production, temporal gland secretion and urine dribbling, heightened aggression and sexual behavior, and therefore can pose unique challenges for human safety and animal welfare. This study characterized longitudinal (9 to 22 years) patterns of circulating testosterone and cortisol in relation to musth in four adult Asian elephant bulls spanning ages from 12 to 54 years. Age-related effects on musth activity and adrenal responses to social changes and clinical health events were also examined. All bulls exhibited regular annual musth cycles. Circulating cortisol covaried positively with testosterone and musth, highlighting intrinsic patterns that should be considered when evaluating the impact of social, health, and environmental changes on adrenal glucocorticoid activity. Except for an end-of-life cortisol increase in one bull, there was no clear evidence of chronically elevated cortisol secretion outside of musth in any individual. Testosterone decreased with age in sexually mature bulls, whereas age-related changes in cortisol varied across individuals, with the three older bulls showing the greatest rate of change during musth versus inter-musth periods. In contrast to physiological factors, there was no evidence of social factors, such as addition of a new male and death of male herdmates, impacting adrenal glucocorticoid activity in these bulls in the short term. Changes in cortisol were associated with treatment for Mycobacterium tuberculosis (M. tb) in two bulls, increasing after start of treatment and decreasing with cessation of treatment, but were not clearly associated with activation of disease. This study highlights the importance of longitudinal hormone monitoring to track changes in physiological function and responses to social, health, and environmental change in elephant bulls, which is important for making more informed decisions on how to manage male elephants under varying degrees of human care to ensure welfare and safety.
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14
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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] [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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15
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Carlin E, J. Somers M, Scheun J, Campbell R, Ganswindt A. Quantification of faecal glucocorticoid metabolites as a measure of stress in the rock hyrax
Procavia capensis
living in an urban green space. WILDLIFE BIOLOGY 2021. [DOI: 10.1002/wlb3.01011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- E. Carlin
- Mammal Research Inst., Dept of Zoology and Entomology, Univ. of Pretoria Pretoria South Africa
| | - M. J. Somers
- Mammal Research Inst., Dept of Zoology and Entomology, Univ. of Pretoria Pretoria South Africa
- Centre for Invasion Biology, Univ. of Pretoria Pretoria South Africa
| | - J. Scheun
- Mammal Research Inst., Dept of Zoology and Entomology, Univ. of Pretoria Pretoria South Africa
- Dept of Life and Consumer Sciences, Univ. of South Africa Pretoria South Africa
| | - R. Campbell
- National Zoological Garden, South African National Biodiversity Inst. Pretoria South Africa
| | - A. Ganswindt
- Mammal Research Inst., Dept of Zoology and Entomology, Univ. of Pretoria Pretoria South Africa
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16
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Effects of Positive Reinforcement Training and Novel Object Exposure on Salivary Cortisol Levels under Consideration of Individual Variation in Captive African Elephants ( Loxodonta africana). Animals (Basel) 2021; 11:ani11123525. [PMID: 34944300 PMCID: PMC8698154 DOI: 10.3390/ani11123525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 11/10/2021] [Accepted: 12/07/2021] [Indexed: 12/04/2022] Open
Abstract
Simple Summary Regular training for medical or enrichment purposes and the provision of environmental enrichment, such as varied feeding schedules and novel objects, are part of the management of African elephants in zoos. The present study aimed to find out whether training and enrichment in the form of a novel object induced physiological changes in captive African elephants. We repeatedly sampled the saliva of ten animals (three zoos) before and after training and the exposure to a novel object for the analysis of cortisol and as a measure of stress and arousal. We found high salivary cortisol levels before and low levels after training. A novel object, in contrast, moderately increased the salivary cortisol levels. Moreover, males and young elephants showed lower salivary cortisol levels than females and old elephants, respectively. The zoo, handling method (free vs. protected contact to keepers), reproductive and social status, however, did not influence the salivary cortisol levels of the animals studied. We conclude that the relatively high cortisol values before training could be due to anticipation of the training event. A novel object, in contrast, may have evoked arousal, which led to the observed cortisol increase. In addition, understanding why animals differ in stress responses will help to manage stress in zoo elephants with the goal of ensuring their welfare. Abstract Dealing with potential stress in species that have high husbandry requirements, such as elephants, is a challenge for zoos. The objective of the present study was to determine whether positive reinforcement training (PRT) and exposure to a novel object (NOV) for enrichment induced a salivary cortisol response indicative of activation of the hypothalamic–pituitary–adrenal (HPA) axis and which factors determine individual variation in this regard in captive African elephants. We repeatedly sampled the saliva of ten animals (three zoos) for the analysis of cortisol (SACort) before and up to 60 min (in 10–15 min intervals) after the onset of PRT (three repeats) or NOV (nine repeats), which lasted 10 min. There was considerable individual variation in SACort in response to PRT or NOV. Using mixed models, we were able to control these and to reveal that PRT was associated with high SACort before and relatively low SACort after PRT, while NOV induced a moderate SACort increase. The individual differences in SACort were related to age and sex (NOV), while the effects of zoo, handling method (free vs. protected contact) and reproductive and social status were variable. We conclude that positive affective states, such as anticipation or arousal, should be taken into account when interpreting the differences in the SACort responses between PRT and NOV. In addition, understanding the individuality of stress will support management decisions aimed at promoting captive elephant welfare.
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17
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Non-Invasive Determination of Annual Fecal Cortisol, Androstenedione, and Testosterone Variations in a Herd of Male Asian Elephants ( Elephas maximus) and Their Relation to Some Climatic Variables. Animals (Basel) 2021; 11:ani11092723. [PMID: 34573690 PMCID: PMC8467623 DOI: 10.3390/ani11092723] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 09/13/2021] [Accepted: 09/14/2021] [Indexed: 11/17/2022] Open
Abstract
Simple Summary Studies of physiology, animal welfare, and behavior in endangered species are gaining more importance with the aim of contributing to their conservation, and studies that use non-invasive methods for hormonal determinations are especially valuable. In this study, feces were used to assess whether the adrenal and gonadal hormones showed variation in male Asian elephants in a 14-month period and to evaluate whether there were any influences of climatic variables with respect to hormonal secretion. We show here that the use of non-invasive methods to measure the levels of steroid hormones in Asian elephant feces allows us to obtain useful results without having to subject the animals to stressful activity or requiring specific training to obtain the samples. Additionally, this research provides a deeper understanding of endocrine regulation in captive Asian elephants (Elephas maximus) in order to enhance reproduction programs in captivity and conserve the species. Abstract The measurement of stress and reproductive hormones in wild animal species by non-invasive methods is of special interest. To assess whether the adrenal and gonadal hormones show annual variations in male Asian elephants (Elephas maximus) and to evaluate whether there is any influence of climatic variables on hormonal secretion, fecal samples were taken from a herd of 7 Asian elephants over a 14-month period to subsequently determine the concentrations of testosterone (T), androstenedione (A4), and cortisol (C) by a validated immunoassay technique. Data referring to three climatic variables in the place and period of study were collected, namely monthly mean values of temperature, humidity and rainfall. Levels of T and A4 showed two major increases in July (T: 1088.35 ± 131.04 ng/g; A4: 480.40 ± 50.86 ng/g) and October (T: 825.09 ± 31.60 ng/g; A4: 319.96 ± 32.69 ng/g) (p < 0.05). Our results show a secretion of fecal androgens dependent on temperature (T and A4), and humidity (T). Male musth was detected during the initial increases of T and A4 levels. The highest concentrations of C were observed in September (156.67 ± 60.89 ng/g) (p < 0.05), probably due to the stressful fights that occurred during the musth period. The observed results of the fecal levels of T, A4 and C were similar to those obtained by invasive methods. In conclusion, fecal secretion of the three hormones in these captive male Asian elephants showed variations related in some cases to different weather factors.
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18
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Hinchcliffe DL, Lea JMD, Palme R, Shultz S. Fecal Glucocorticoid Metabolites as Biomarkers in Equids: Assay Choice Matters. J Wildl Manage 2021. [DOI: 10.1002/jwmg.22066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
| | - Jessica M. D. Lea
- School of Earth and Environmental Sciences University of Manchester United Kingdom
| | - Rupert Palme
- Department of Biomedical Sciences University of Veterinary Medicine Vienna Austria
| | - Susanne Shultz
- School of Earth and Environmental Sciences University of Manchester United Kingdom
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19
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Effects of early life adversity on maternal effort and glucocorticoids in wild olive baboons. Behav Ecol Sociobiol 2021. [DOI: 10.1007/s00265-021-03056-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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20
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Wolf TE, De Haast AR, Meyer L, Gerber D, Ganswindt A. Measuring Faecal Glucocorticoid Metabolite Concentrations as an Indicator of Stress in Blue Wildebeest (Connochaetes taurinus). AFRICAN JOURNAL OF WILDLIFE RESEARCH 2021. [DOI: 10.3957/056.051.0090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Affiliation(s)
- Tanja E. Wolf
- Mammal Research Institute, Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria, 0028 South Africa
| | - Adel R. De Haast
- Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, 0110 South Africa
| | - Leith Meyer
- Mammal Research Institute, Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria, 0028 South Africa
| | - David Gerber
- V-Tech (Pty) Ltd, Corner Old Pretoria and Douglas Roads, Midrand, 0182 South Africa
| | - Andre Ganswindt
- Mammal Research Institute, Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria, 0028 South Africa
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21
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Harrison ND, Maag N, Haverkamp PJ, Ganswindt A, Manser MB, Clutton-Brock TH, Ozgul A, Cozzi G. Behavioural change during dispersal and its relationship to survival and reproduction in a cooperative breeder. J Anim Ecol 2021; 90:2637-2650. [PMID: 34258771 PMCID: PMC8597146 DOI: 10.1111/1365-2656.13569] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 07/07/2021] [Indexed: 12/12/2022]
Abstract
The ability of dispersing individuals to adjust their behaviour to changing conditions is instrumental in overcoming challenges and reducing dispersal costs, consequently increasing overall dispersal success. Understanding how dispersers' behaviour and physiology change during the dispersal process, and how they differ from resident individuals, can shed light on the mechanisms by which dispersers increase survival and maximise reproduction. By analysing individual behaviour and concentrations of faecal glucocorticoid metabolites (fGCM), a stress‐associated biomarker, we sought to identify the proximate causes behind differences in survival and reproduction between dispersing and resident meerkats Suricata suricatta. We used data collected on 67 dispersing and 108 resident females to investigate (a) which individual, social and environmental factors are correlated to foraging and vigilance, and whether the role of such factors differs among dispersal phases, and between dispersers and residents; (b) how time allocated to either foraging or vigilance correlated to survival in dispersers and residents and (c) the link between aggression and change in fGCM concentration, and their relationship with reproductive rates in dispersing groups and resident groups with either long‐established or newly established dominant females. Time allocated to foraging increased across dispersal phases, whereas time allocated to vigilance decreased. Time allocated to foraging and vigilance correlated positively and negatively, respectively, with dispersers' group size. We did not find a group size effect for residents. High proportions of time allocated to foraging correlated with high survival, and more so in dispersers, suggesting that maintaining good physical condition may reduce mortality during dispersal. Furthermore, while subordinate individuals rarely reproduced in resident groups, the conception rate of subordinates in newly formed dispersing groups was equal to that of their dominant individuals. Mirroring conception rates, in resident groups, fGCM concentrations were lower in subordinates than in dominants, whereas in disperser groups, fGCM concentrations did not differ between subordinates and dominants. Our results, which highlight the relationship between behavioural and physiological factors and demographic rates, provide insights into some of the mechanisms that individuals of a cooperative species can use to increase overall dispersal success.
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Affiliation(s)
- Natasha D Harrison
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland.,Kalahari Research Centre, Kuruman River Reserve, Van Zylsrus, South Africa
| | - Nino Maag
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland.,Kalahari Research Centre, Kuruman River Reserve, Van Zylsrus, South Africa
| | - Paul J Haverkamp
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
| | - André Ganswindt
- Mammal Research Institute, University of Pretoria, Hatfield, South Africa
| | - Marta B Manser
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland.,Kalahari Research Centre, Kuruman River Reserve, Van Zylsrus, South Africa
| | - Tim H Clutton-Brock
- Kalahari Research Centre, Kuruman River Reserve, Van Zylsrus, South Africa.,Mammal Research Institute, University of Pretoria, Hatfield, South Africa.,Department of Zoology, University of Cambridge, Cambridge, UK
| | - Arpat Ozgul
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland.,Kalahari Research Centre, Kuruman River Reserve, Van Zylsrus, South Africa
| | - Gabriele Cozzi
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland.,Kalahari Research Centre, Kuruman River Reserve, Van Zylsrus, South Africa
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22
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Association between stress and bilateral symmetrical alopecia in free-ranging Formosan macaques in Mt. Longevity, Taiwan. Sci Rep 2021; 11:11189. [PMID: 34045621 PMCID: PMC8160012 DOI: 10.1038/s41598-021-90725-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 05/17/2021] [Indexed: 02/04/2023] Open
Abstract
Since 2013, a high incidence of bilateral symmetrical alopecia has been observed in free-ranging Formosan macaques (Macaca cyclopis) in Mt. Longevity, Taiwan. We hypothesized that stress induces alopecia in this population. To verify our hypothesis, we evaluated the histopathological characteristics of skin biopsy and used a validated enzyme immunoassay (EIA) for fecal glucocorticoid metabolite (FGM) analysis, which act as an indicator of stress experienced by the individual. Follicular densities were lower (2.1-3.0 mm2) in individuals with symmetrical alopecia than in those with normal hair conditions (4.7 mm2). Furthermore, anagen to catagen/telogen ratios were lower in individuals with alopecia (0-1.4) than in those with normal hair (4.0). The histopathological characteristics of alopecia were similar to those of telogen effluvium, which indicates that stress is one of the possible etiologies. On the basis of the analytical and biological validation of EIAs for FGM analysis, 11β-hydroxyetiocholanolone was considered suitable for monitoring adrenocortical activity in both sexes of Formosan macaques. The mean concentrations (standard error; sample size) of 11β-hydroxyetiocholanolone were 2.02 (0.17; n = 10) and 1.41 (0.10; n = 31) μg/g for individuals with and without alopecia, respectively. Furthermore, the results of logistic regression analysis show that 11β-hydroxyetiocholanolone (p = 0.012) concentration was positively associated with alopecia. Thus, stress was the most likely to trigger symmetrical alopecia in Formosan macaques in Mt. Longevity. Although stress can decrease the fitness of an individual, considering the population status of Formosan macaques in Taiwan is stable and alopecia was only observed in our study area, which is isolated from other populations, the impact on the total population of Formosan macaque in Taiwan is limited. Nonetheless, stress-induced immunosuppression and alopecia might affect the local abundance and increase zoonosis risk due to frequent human-macaque contact in Mt. Longevity. Future studies are suggested to focus on the causative factor of stress and the effects of stress and alopecia on the health and welfare in the Formosan macaques.
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23
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Rasmussen SL, Kalliokoski O, Dabelsteen T, Abelson K. An exploratory investigation of glucocorticoids, personality and survival rates in wild and rehabilitated hedgehogs (Erinaceus europaeus) in Denmark. BMC Ecol Evol 2021; 21:96. [PMID: 34022803 PMCID: PMC8141197 DOI: 10.1186/s12862-021-01816-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Accepted: 05/06/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The European population of hedgehogs (Erinaceus europaeus) is declining. It is therefore essential to optimise conservation initiatives such as the rehabilitation of sick, injured and orphaned hedgehogs. Wild animals placed in captivity may be prone to chronic stress, potentially causing negative health effects. Therefore, the effects of these rehabilitation efforts should consequently be evaluated. Furthermore, hand-raising orphaned hedgehogs is a laborious and costly task, and it is therefore relevant to document whether they have equal post release survival rates compared to their wild conspecifics. The objectives of this research were therefore to conduct an exploratory study of glucocorticoid levels in hedgehogs from different backgrounds and compare the post release survival of translocated, rehabilitated and wild, juvenile hedgehogs as well as the possible effect on survival of differences in shy or bold behaviour (personality) exhibited by individuals. RESULTS We measured glucocorticoid levels in 43 wild-caught (n = 18) and rehabilitated (n = 25) hedgehogs and compared the post release survival and spatial behaviour of 18 translocated juvenile hedgehogs (eight hand-raised and ten wild) until hibernation. The possible effect on survival of differences in shy or bold behaviour (personality) exhibited by 17 juvenile individuals (seven hand-raised and ten wild) was also examined. Rehabilitated individuals and females had higher levels of faecal corticosterone metabolites compared to wild individuals and males, respectively. Rehabilitated individuals showed higher levels of saliva corticosterone than wild. The personality tests labelled 13 individuals as shy and 11 as bold. Post release survival was 57% for rehabilitated and 50% for wild individuals. Neither background nor personality affected post release survival. Home range measures were 3.54 and 4.85 ha. Mean dispersal length from the release sites was 217 ± 100 m. CONCLUSION The higher levels of corticosterone observed in rehabilitated compared to wild hedgehogs calls for consideration of the duration of admission to wildlife rehabilitation centres to reduce stress levels in the patients. Hand-raised juveniles appear to have the same prospects as wild, and personality does not seem to affect post release survival in hedgehogs, indicating that hand-raising of orphaned juvenile hedgehogs is a relevant contribution to the conservation of this species.
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Affiliation(s)
- Sophie Lund Rasmussen
- Wildlife Conservation Research Unit, Department of Zoology, The Recanati-Kaplan Centre, University of Oxford, Tubney House, Abingdon Road, Tubney, Abingdon, OX13 5QL, UK. .,Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej, 7H, 9220, Aaborg, Denmark. .,Department of Biology, Section for Ecology and Evolution, University of Copenhagen, Universitetsparken 15, Building 12, 2100, Copenhagen Ø, Denmark.
| | - Otto Kalliokoski
- Department of Experimental Medicine, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen N, Denmark
| | - Torben Dabelsteen
- Department of Biology, Section for Ecology and Evolution, University of Copenhagen, Universitetsparken 15, Building 12, 2100, Copenhagen Ø, Denmark
| | - Klas Abelson
- Department of Experimental Medicine, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen N, Denmark
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24
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The cost of associating with males for Bornean and Sumatran female orangutans: a hidden form of sexual conflict? Behav Ecol Sociobiol 2020; 75:6. [PMID: 33408436 PMCID: PMC7773621 DOI: 10.1007/s00265-020-02948-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 12/02/2020] [Accepted: 12/09/2020] [Indexed: 12/29/2022]
Abstract
Abstract Sexual coercion, in the form of forced copulations, is relatively frequently observed in orangutans and generally attributed to their semi-solitary lifestyle. High ecological costs of association for females may be responsible for this lifestyle and may have prevented the evolution of morphological fertility indicators (e.g., sexual swellings), which would attract (male) associates. Therefore, sexual conflict may arise not only about mating per se but also about associations, because males may benefit from associations with females to monitor their reproductive state and attempt to monopolize their sexual activities. Here, we evaluate association patterns and costs for females when associating with both males and females of two different orangutan species at two study sites: Suaq, Sumatra (Pongo abelii), and Tuanan, Borneo (Pongo pygmaeus wurmbii). Female association frequency with both males and females was higher in the Sumatran population, living in more productive habitat. Accordingly, we found that the cost of association, in terms of reduced feeding to moving ratio and increased time being active, is higher in the less sociable Bornean population. Males generally initiated and maintained such costly associations with females, and prolonged associations with males led to increased female fecal cortisol metabolite (FCM) levels at Tuanan, the Bornean population. We conclude that male-maintained associations are an expression of sexual conflict in orangutans, at least at Tuanan. For females, this cost of association may be responsible for the lack of sexual signaling, while needing to confuse paternity. Significance statement Socioecological theory predicts a trade-off between the benefits of sociality and the ecological costs of increased feeding competition. Orangutans’ semi-solitary lifestyle has been attributed to the combination of high association costs and low predation risk. Previous work revealed a positive correlation between association frequencies and habitat productivity, but did not measure the costs of association. In this comparative study, we show that females likely incur costs from involuntary, male-maintained associations, especially when they last for several days and particularly in the population characterized by lower association frequencies. Association maintenance therefore qualifies as another expression of sexual conflict in orangutans, and especially prolonged, male-maintained associations may qualify as an indirect form of sexual coercion. Supplementary Information The online version contains supplementary material available at 10.1007/s00265-020-02948-4.
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Grotto CE, Wolf T, Berkeley E, Lee S, Ganswindt A. Physiological measure of animal welfare in relation to semi-captive African Elephant (Loxodonta africana) interaction programs. AFRICAN ZOOLOGY 2020. [DOI: 10.1080/15627020.2020.1776635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Chloe E Grotto
- Department of Anatomy and Physiology, University of Pretoria, Onderstepoort, South Africa
| | - Tanja Wolf
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
| | - Elizabeth Berkeley
- Department of Biology and Earth Science, Otterbein University, Westerville, Ohio, United States
| | - Stephen Lee
- Department of the US Army Research Office, Research Triangle Park, North Carolina, United States
| | - Andre Ganswindt
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
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Carrera SC, Sen S, Heistermann M, Lu A, Beehner JC. Low rank and primiparity increase fecal glucocorticoid metabolites across gestation in wild geladas. Gen Comp Endocrinol 2020; 293:113494. [PMID: 32333913 DOI: 10.1016/j.ygcen.2020.113494] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 03/07/2020] [Accepted: 04/21/2020] [Indexed: 11/20/2022]
Abstract
Integrative behavioral ecology requires accurate and non-invasive measures of hormone mediators for the study of wild animal populations. Biologically sensitive assay systems for the measurement of hormones and their metabolites need to be validated for the species and sample medium (e.g. urine, feces, saliva) of interest. Where more than one assay is available for hormone (metabolite) measurement, antibody selection is useful in identifying the assay that tracks changes in an individuaĺs endocrine activity best, i.e., the most biologically sensitive assay. This is particularly important when measuring how glucocorticoids (GCs) respond to the subtle, additive effects of acute stressors during a predictable metabolic challenge, such as gestation. Here, we validate a group-specific enzyme immunoassay, measuring immunoreactive 11β-hydroxyetiocholanolone, for use in a wild primate, geladas (Theropithecus gelada). This group-specific assay produced values correlated with those from a previously validated double-antibody, corticosterone 125I radioimmunoassay. However, the results with the group-specific assay showed a stronger response to an ACTH challenge and identified greater variation in gelada immunoreactive fecal glucocorticoid metabolites (iGCMs) compared with the corticosterone assay, indicating a higher biological sensitivity for assessing adrenocortical activity. We then used the group-specific assay to: (1) determine the normative pattern of iGCM levels across gelada gestation, and (2) identify the ecological, social, and individual factors that influence GC output for pregnant females. Using a general additive mixed model, we found that higher iGCM levels were associated with low rank (compared to high rank) and first time mothers (compared to multiparous mothers). This study highlights the importance of assay selection and the efficacy of group-specific assays for hormonal research in non-invasively collected samples. Additionally, in geladas, our results identify some of the factors that increase GC output over and above the already-elevated GC concentrations associated with gestation. In the burgeoning field of maternal stress, these factors can be examined to identify the effects that GC elevations may have on offspring development.
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Affiliation(s)
- Sofia C Carrera
- Department of Psychology, University of Michigan, Ann Arbor, MI 48109, USA.
| | - Sharmi Sen
- Department of Anthropology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Michael Heistermann
- Endocrinology Laboratory, German Primate Center, Leibniz Institute for Primate Research, 37077 Göttingen, Germany
| | - Amy Lu
- Department of Anthropology, SUNY Stony Brook, Stony Brook, NY 11794, USA
| | - Jacinta C Beehner
- Department of Psychology, University of Michigan, Ann Arbor, MI 48109, USA; Department of Anthropology, University of Michigan, Ann Arbor, MI 48109, USA
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Non-Invasive Assessment of Body Condition and Stress-Related Fecal Glucocorticoid Metabolite Concentrations in African Elephants ( Loxodonta africana) Roaming in Fynbos Vegetation. Animals (Basel) 2020; 10:ani10050814. [PMID: 32397066 PMCID: PMC7278398 DOI: 10.3390/ani10050814] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 04/22/2020] [Accepted: 04/27/2020] [Indexed: 11/17/2022] Open
Abstract
Simple Summary The Western Cape Province of South Africa is characterized by Fynbos vegetation. This unique endemic vegetation type belongs to the Cape Floral Kingdom, the smallest of the six floral kingdoms in the world, and only a few provincial, national and private game reserves in this area currently support populations of African elephants (Loxodonta africana). As a result, not much is known about the ability of elephants to thrive in such a unique environment. External factors such as a nutritionally poor diet can be perceived as a stressor by mammals, and establishing links between these two factors was the focus of this study. The results of monitoring individual stress-related hormone levels and body conditions suggest that elephants can obtain adequate nutrition from Fynbos vegetation. Abstract Fynbos is a unique endemic vegetation type belonging to the Cape Floral Kingdom in the Western Cape Province of South Africa, representing the smallest of the six floral kingdoms in the world. Nowadays, only a few game reserves in this region support populations of African elephants (Loxodonta africana), and thus, little information exists regarding the suitability of the nutritionally poor Fynbos vegetation for these megaherbivores. Using already established non-invasive methods, the monitoring of individual body conditions and fecal glucocorticoid metabolite (fGCM) concentrations, as a measure of physiological stress, was performed to examine a herd of 13 elephants in a Western Cape Province Private Game Reserve, during two monitoring periods (April and June 2018), following a severe drought. The results indicate that overall median body condition scores (April and June: 3.0, range 2.0–3.0) and fGCM concentrations (April: 0.46 µg/g dry weight (DW), range 0.35–0.66 µg/g DW; June: 0.61 µg/g DW, range 0.22–1.06 µg/g DW) were comparable to those of other elephant populations previously studied utilizing the same techniques. These findings indicate that the individuals obtain sufficient nutrients from the surrounding Fynbos vegetation during the months monitored. However, a frequent assessment of body conditions and stress-associated fGCM concentrations in these animals would assist conservation management authorities and animal welfare practitioners in determining ways to manage this species in environments with comparably poorer nutritional vegetation.
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Hein A, Palme R, Baumgartner K, von Fersen L, Woelfing B, Greenwood AD, Bechshoft T, Siebert U. Faecal glucocorticoid metabolites as a measure of adrenocortical activity in polar bears ( Ursus maritimus). CONSERVATION PHYSIOLOGY 2020; 8:coaa012. [PMID: 32274062 PMCID: PMC7125046 DOI: 10.1093/conphys/coaa012] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 01/23/2020] [Accepted: 02/04/2020] [Indexed: 06/11/2023]
Abstract
Analysis of faecal glucocorticoid metabolites (FGMs) is frequently applied to assess adrenocortical activity in animal conservation and welfare studies. Faecal sample collection is non-invasive and feasible under field conditions. FGM levels are also less prone to circadian rhythms, episodic fluctuations and short acute stressors than glucocorticoid (GC) levels obtained from other matrices, for example blood or saliva. To investigate the suitability of FGM measurement in polar bears (Ursus maritimus), a species listed as Vulnerable by the IUCN (International Union for Conservation of Nature), a cortisol enzyme immunoassay (EIA) was biologically validated by demonstrating a significant increase in FGMs after five zoo-to-zoo transports. In addition to validating the method, the study also documented an average delay of 7 h until the first occurrence of food colorants in the monitored polar bears, which provides essential information for future studies. After validation, the assay was applied to measure FGM concentrations of five polar bears over a 1-year period. Several pre-defined potentially stressful events were recorded in an event log to measure their effect on FGM concentrations. A mixed model analysis revealed significant increases in FGM concentrations after social tension and environmental changes, whereas season and sex had no significant effect. The study demonstrates that the applied cortisol EIA is suitable for measuring FGM levels in polar bears and that using a carefully validated assay for FGM analysis in combination with a detailed sampling protocol can serve as a valuable tool for evaluating mid- to long-term stress in polar bears. FGM levels can be used to monitor stress in captive polar bears in order to optimize housing conditions but also to elucidate stress responses in wild populations for targeted conservation measures.
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Affiliation(s)
- Anna Hein
- Institute for Terrestrial and Aquatic Wildlife Research (ITAW), University of Veterinary Medicine Hannover, Bischofsholer Damm 15, 30173 Hannover, Germany
| | - Rupert Palme
- Unit of Physiology, Pathophysiology, and Experimental Endocrinology, De for Biomedical Sciences, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Vienna, Austria
| | | | | | - Benno Woelfing
- Institute for Terrestrial and Aquatic Wildlife Research (ITAW), University of Veterinary Medicine Hannover, Bischofsholer Damm 15, 30173 Hannover, Germany
| | - Alex D Greenwood
- Department of Wildlife Diseases, Leibniz-Institute for Zoo and Wildlife Research, Alfred-Kowalke-Strasse 17, 10315 Berlin, Germany
- Department of Veterinary Medicine, Freie Universität Berlin, Oertzenweg 19b, 14163 Berlin, Germany
| | - Thea Bechshoft
- Department of Bioscience, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark
| | - Ursula Siebert
- Institute for Terrestrial and Aquatic Wildlife Research (ITAW), University of Veterinary Medicine Hannover, Bischofsholer Damm 15, 30173 Hannover, Germany
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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] [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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Thompson NA, Higham JP, Heistermann M, Vogel E, Cords M. Energy balance but not competitive environment corresponds with allostatic load during development in an Old World monkey. Horm Behav 2020; 119:104664. [PMID: 31899261 DOI: 10.1016/j.yhbeh.2019.104664] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 12/21/2019] [Accepted: 12/24/2019] [Indexed: 11/24/2022]
Abstract
Primates develop slowly relative to their body size, a pattern posited to result from ecological risk aversion. Little is known, however, about how energy balance contributes to allostatic load in juveniles. Using data collected over 8 consecutive months, we examined variation in energy balance (as measured by urinary C-peptide) and how energy balance, life history status, and social competition related to allostatic load (as measured by deviation from baseline fecal glucocorticoid metabolites, dfGCs) in 41 wild juvenile blue monkeys from 3 social groups. Juvenile energy balance was higher among females, older juveniles, when ripe fruit was more available, and when rainfall was lower. Energy balance, but not life history or competitive environments, predicted dfGC concentrations, such that juveniles generally had lower mean dfGCs when they had higher energy balance. An additional exploratory analysis of how dfGCs relate to social strategies revealed that subjects had lower dfGCs when they groomed less, and played more. Time spent grooming interacted with energy balance in predicting dfGC concentrations, so that individuals that groomed more actually had higher dfGCs when they had higher energy balance. Together these results reveal that energetic deficiencies are a true ecological risk factor in blue monkeys, and suggest that navigating the social environment via overt affiliative behavior is potentially both a stress-relieving and stress-inducing endeavor during development.
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Affiliation(s)
- Nicole A Thompson
- Columbia University, Department of Ecology, Evolution, and Environmental Biology, United States of America; New York Consortium in Evolutionary Primatology, United States of America.
| | - James P Higham
- New York Consortium in Evolutionary Primatology, United States of America; New York University, Department of Anthropology, United States of America
| | | | - Erin Vogel
- Rutgers University, Department of Anthropology, United States of America
| | - Marina Cords
- Columbia University, Department of Ecology, Evolution, and Environmental Biology, United States of America; New York Consortium in Evolutionary Primatology, United States of America
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Defolie C, Merkling T, Fichtel C. Patterns and variation in the mammal parasite-glucocorticoid relationship. Biol Rev Camb Philos Soc 2020; 95:74-93. [PMID: 31608587 DOI: 10.1111/brv.12555] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 08/23/2019] [Accepted: 09/03/2019] [Indexed: 01/24/2023]
Abstract
Parasites are ubiquitous and can strongly affect their hosts through mechanisms such as behavioural changes, increased energetic costs and/or immunomodulation. When parasites are detrimental to their hosts, they should act as physiological stressors and elicit the release of glucocorticoids. Alternatively, previously elevated glucocorticoid levels could facilitate parasite infection due to neuroimmunomodulation. However, results are equivocal, with studies showing either positive, negative or no relationship between parasite infection and glucocorticoid levels. Since factors such as parasite type, infection severity or host age and sex can influence the parasite-glucocorticoid relationship, we review the main mechanisms driving this relationship. We then perform a phylogenetic meta-analysis of 110 records from 65 studies in mammalian hosts from experimental and observational studies to quantify the general direction of this relationship and to identify ecological and methodological drivers of the observed variability. Our review produced equivocal results concerning the direction of the relationship, but there was stronger support for a positive relationship, although causality remained unclear. Mechanisms such as host manipulation for parasite survival, host response to infection, cumulative effects of multiple stressors, and neuro-immunomodulatory effects of glucocorticoids could explain the positive relationship. Our meta-analysis results revealed an overall positive relationship between glucocorticoids and parasitism among both experimental and observational studies. Because all experimental studies included were parasite manipulations, we conclude that parasites caused in general an increase in glucocorticoid levels. To obtain a better understanding of the directionality of this link, experimental manipulation of glucocorticoid levels is now required to assess the causal effects of high glucocorticoid levels on parasite infection. Neither parasite type, the method used to assess parasite infection nor phylogeny influenced the relationship, and there was no evidence for publication bias. Future studies should attempt to be as comprehensive as possible, including moderators potentially influencing the parasite-glucocorticoid relationship. We particularly emphasise the importance of testing hosts of a broad age range, concomitantly measuring sex hormone levels or at least reproductive status, and for observational studies, also considering food availability, host body condition and social stressors to obtain a better understanding of the parasite-glucocorticoid relationship.
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Affiliation(s)
- Charlotte Defolie
- Sociobiology/Anthropology Department, University of Göttingen, Kellnerweg 6, 37077, Göttingen, Germany.,Behavioral Ecology & Sociobiology Unit, German Primate Center, Leibniz Institute for Primate Research, Kellnerweg 4, 37077, Göttingen, Germany.,Leibniz ScienceCampus "Primate Cognition", German Primate Center, Kellnerweg 4, 37077, Göttingen, Germany
| | - Thomas Merkling
- Department of Natural Resource Sciences, McGill University, Macdonald-Stewart Building, 21111 Lakeshore Road, Ste. Anne de Bellevue, Québec, H9X 3V9, Canada
| | - Claudia Fichtel
- Behavioral Ecology & Sociobiology Unit, German Primate Center, Leibniz Institute for Primate Research, Kellnerweg 4, 37077, Göttingen, Germany.,Leibniz ScienceCampus "Primate Cognition", German Primate Center, Kellnerweg 4, 37077, Göttingen, Germany
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Szott ID, Pretorius Y, Ganswindt A, Koyama NF. Physiological stress response of African elephants to wildlife tourism in Madikwe Game Reserve, South Africa. WILDLIFE RESEARCH 2020. [DOI: 10.1071/wr19045] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Abstract
ContextWildlife tourism has been shown to increase stress in a variety of species and can negatively affect survival, reproduction, welfare, and behaviour of individuals. In African elephants, Loxodonta africana, increased physiological stress has been linked to use of refugia, rapid movement through corridors, and heightened aggression towards humans. However, we are unaware of any studies assessing the impact of tourism pressure (tourist numbers) on physiological stress in elephants.
AimsWe used faecal glucocorticoid metabolite (fGCM) concentrations to investigate whether tourist numbers in Madikwe Game Reserve, South Africa, were related to changes in physiological stress in elephants.
MethodsWe repeatedly collected dung samples (n=43) from 13 individually identified elephants over 15 months. Using a generalised linear mixed model and a Kenward–Roger approximation, we assessed the impact of monthly tourist numbers, season, age, and sex on elephant fGCM concentrations.
Key resultsHigh tourist numbers were significantly related to elevated fGCM concentrations. Overall, fGCM concentrations increased by 112% (from 0.26 to 0.55µgg−1 dry weight) in the months with the highest tourist pressure, compared to months with the lowest tourist pressure.
ConclusionsManagers of fenced reserves should consider providing potential alleviation measures for elephants during high tourist pressure, for example, by ensuring that refuge areas are available. This may be of even higher importance if elephant populations have had traumatic experiences with humans in the past, such as poaching or translocation. Such management action will improve elephant welfare and increase tourist safety.
ImplicationsAlthough tourism can generate substantial revenue to support conservation action, careful monitoring of its impact on wildlife is required to manage potential negative effects.
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Rincon AV, Ostner J, Heistermann M, Deschner T. Measuring urinary cortisol and testosterone levels in male Barbary macaques: A comparison of EIA and LC-MS. Gen Comp Endocrinol 2019; 281:117-125. [PMID: 31145893 DOI: 10.1016/j.ygcen.2019.05.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Revised: 04/04/2019] [Accepted: 05/26/2019] [Indexed: 01/03/2023]
Abstract
The development of methods to quantify hormones from non-invasively collected samples such as urine or feces has facilitated endocrinology research on wild-living animals. To ensure that hormone measurements are biologically meaningful, method validations are strongly recommended for each new species or sample matrix. Our aim was to validate three commonly used enzyme immunoassays (EIA), one for analysis of cortisol and two for analysis of testosterone, to assess adrenocortical and gonadal endocrine activity, respectively, from the urine of male Barbary macaques. We compared EIA and liquid chromatography-mass spectrometry (LC-MS) results to determine if the EIA measurements truly reflect levels of the target hormone and to determine if antibody cross-reactivities with other steroids were potentially confounding results. Furthermore, we conducted a biological validation of testosterone to ensure that both EIA and LC-MS were able to capture physiologically meaningful differences in hormone levels. We found that cortisol measured by EIA correlated strongly with cortisol measured by LC-MS in both adult and immature males, without the need for deconjugation of steroids in the urine. Both testosterone EIAs correlated strongly with LC-MS in adult males, but only if steroids in the urine were deconjugated by enzymatic hydrolysis prior to analysis. However, in immature males, EIA and LC-MS results did not correlate significantly. Further correlation analyses suggest this is likely due to cross-reactivity of the testosterone antibodies with other adrenal steroids such as cortisol, DHEA, and likely others, which are present at much higher concentrations relative to testosterone in immature males. Testosterone levels were significantly higher in adult compared to immature males as measured by LC-MS but not as measured by EIA. Taken together, our results suggest that the testosterone EIAs are suitable to assess gonadal activity in adult but not immature males, and only if a hydrolysis of the urine is conducted prior to analysis.
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Affiliation(s)
- Alan V Rincon
- Department of Behavioral Ecology, Johann-Friedrich-Blumenbach Institute for Zoology and Anthropology, University of Goettingen, Goettingen, Germany; Leibniz ScienceCampus Primate Cognition, Goettingen, Germany.
| | - Julia Ostner
- Department of Behavioral Ecology, Johann-Friedrich-Blumenbach Institute for Zoology and Anthropology, University of Goettingen, Goettingen, Germany; Leibniz ScienceCampus Primate Cognition, Goettingen, Germany; Research Group Social Evolution in Primates, German Primate Center, Leibniz Institute for Primate Research, Goettingen, Germany
| | - Michael Heistermann
- Endocrinology Laboratory, German Primate Center, Leibniz Institute for Primate Research, Goettingen, Germany
| | - Tobias Deschner
- Department of Primatology, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
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Lavin SR, Woodruff MC, Atencia R, Cox D, Woodruff GT, Setchell JM, Wheaton CJ. Biochemical and biological validations of a faecal glucocorticoid metabolite assay in mandrills ( Mandrillus sphinx). CONSERVATION PHYSIOLOGY 2019; 7:coz032. [PMID: 31528347 PMCID: PMC6736364 DOI: 10.1093/conphys/coz032] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 05/01/2019] [Accepted: 05/16/2019] [Indexed: 06/10/2023]
Abstract
Stress is a major factor in determining success when releasing endangered species into the wild but is often overlooked. Mandrills (Mandrills sphinx) are vulnerable to extinction due to habitat loss and demand for bush meat and the pet trade. To help bolster in situ populations, rehabilitated rescued mandrills recently were released into a protected area in the Republic of Congo. The goal of this study was to validate the use of faecal glucocorticoid metabolite enzyme immunoassays (EIAs) in mandrills and test field-friendly faecal hormone extraction techniques that can subsequently be used to monitor the stress physiology and welfare of mandrills throughout the release process. Using faecal samples collected from ex situ mandrills, we tested cortisol, corticosterone, 11β-hydroxyetiocholanolone (69a), and 11-oxoetiocholanolone EIAs. Absolute concentrations, hormone profiles following medical procedures or translocation, and high-performance liquid chromatography fraction immunoreactivity showed that the 69a assay was the best choice to monitor the stress response in this species. Samples with delayed extraction or drying times had 40-80% lower 69a concentrations than samples extracted immediately post-collection and frozen. The 69a EIA is an appropriate assay for monitoring welfare in this species in situ or ex situ, and results indicated that consistent extraction methods are important for accurate comparisons.
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Affiliation(s)
- Shana R Lavin
- Animals, Science and Environment, Disney’s Animal Kingdom®, Lake Buena Vista, FL, USA
| | - Miles C Woodruff
- Anthropology Department and Behavior, Ecology and Evolution Research Centre, Durham University, Durham, UK
- The Jane Goodall Institute, Vienna, VA, USA
| | | | - Debby Cox
- The Jane Goodall Institute, Vienna, VA, USA
| | | | - Joanna M Setchell
- Anthropology Department and Behavior, Ecology and Evolution Research Centre, Durham University, Durham, UK
| | - Catharine J Wheaton
- Animals, Science and Environment, Disney’s Animal Kingdom®, Lake Buena Vista, FL, USA
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Chave E, Edwards KL, Paris S, Prado N, Morfeld KA, Brown JL. Variation in metabolic factors and gonadal, pituitary, thyroid, and adrenal hormones in association with musth in African and Asian elephant bulls. Gen Comp Endocrinol 2019; 276:1-13. [PMID: 30735672 DOI: 10.1016/j.ygcen.2019.02.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Revised: 02/03/2019] [Accepted: 02/04/2019] [Indexed: 11/28/2022]
Abstract
Longitudinal analyses of serum testosterone, luteinizing hormone (LH), follicle-stimulating hormone (FSH), prolactin, glucose, insulin, triglycerides, cholesterol, total and free thyroxine (T4), total triiodothyronine (T3), thyroid stimulating hormone (TSH), and cortisol were conducted to investigate pituitary, metabolic, and adrenal changes related to testicular function and musth status in zoo-housed elephant bulls. Blood samples were collected twice a month for 12 months from 14 African and 12 Asian bulls at 17 facilities in North America. Building on previous studies, our results show that musth is associated with increased testosterone, LH, FSH, and cortisol secretion, and a decrease in thyroid hormone (total and free T4) production. In addition, glucose and triglycerides were higher during musth than non-musth periods, indicative of altered sugar and fat metabolism. There were significant differences associated with age for LH, FSH and testosterone, all increasing, whereas the glucose-to-insulin ratio (G:I) decreased with age. A species comparison found African and Asian elephants differed in measures of insulin, prolactin, cholesterol and the G:I. Across all hormones, high inter-individual variability was observed, making it difficult to define a general musth endocrine profile or to assess musth status from single samples. These results highlight the need for facilities hosting bulls to closely and consistently monitor each individual from an early age and throughout musth and non-musth periods to determine the pattern for each male.
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Affiliation(s)
- Emmanuelle Chave
- Center for Species Survival, Smithsonian Conservation Biology Institute, 1500 Remount Rd., Front Royal, VA 22630, USA; Université François-Rabelais, 60 Rue du Plat d'Étain, 37000 Tours, France
| | - Katie L Edwards
- Center for Species Survival, Smithsonian Conservation Biology Institute, 1500 Remount Rd., Front Royal, VA 22630, USA.
| | - Steve Paris
- Center for Species Survival, Smithsonian Conservation Biology Institute, 1500 Remount Rd., Front Royal, VA 22630, USA
| | - Natalia Prado
- Center for Species Survival, Smithsonian Conservation Biology Institute, 1500 Remount Rd., Front Royal, VA 22630, USA
| | - Kari A Morfeld
- Lincoln Children's Zoo, 1222 S 27th Street, Lincoln, NE 68502, USA
| | - Janine L Brown
- Center for Species Survival, Smithsonian Conservation Biology Institute, 1500 Remount Rd., Front Royal, VA 22630, USA.
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Paschek N, Müller N, Heistermann M, Ostner J, Schülke O. Subtypes of aggression and their relation to anxiety in Barbary macaques. Aggress Behav 2019; 45:120-128. [PMID: 30318602 DOI: 10.1002/ab.21801] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 07/09/2018] [Accepted: 07/30/2018] [Indexed: 12/29/2022]
Abstract
Human aggression can be differentiated into reactive aggression (RA), displayed in face of a real or perceived threat and associated with high levels of anxiety, and proactive aggression (PA), displayed to achieve a certain goal and linked to lower anxiety levels. To study the origins of these aggression subtypes and their relation to anxiety, we tested if both subtypes can be distinguished in a nonhuman primate species, characterized their occurrence within the study group, and examined the link between aggression subtype and anxiety. Data were collected on 29 individuals of a semi-free ranging group of Barbary macaques (Macaca sylvanus) at Affenberg Salem, Germany, via focal animal (303 hr) and event sampling (1,222 agonistic events). Using a priori definitions, each aggressive event was classified as either reactive or proactive. We found both aggression types in our study population as well as individual differences in the proportion at which they occurred. The predominant use of one subtype of aggression was linked to the individual's dominance rank, age and sex, but not related to standard behavioral and physiological measures of anxiety. Our results suggest that reactive and proactive subtypes of aggression also exist in Barbary macaques, indicating a deeper evolutionary history of these aggression types observed in humans.
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Affiliation(s)
- Nicole Paschek
- Department of Behavioural Ecology; University of Göttingen; Göttingen Niedersachsen Germany
| | - Nadine Müller
- Department of Behavioural Ecology; University of Göttingen; Göttingen Niedersachsen Germany
| | - Michael Heistermann
- Endocrinology Laboratory; German Primate Center; Leibniz Institute for Primate Research; Göttingen Germany
| | - Julia Ostner
- Department of Behavioural Ecology; University of Göttingen; Göttingen Niedersachsen Germany
- Primate Social Evolution Research Group; German Primate Center; Leibniz Institute for Primate Research; Göttingen Niedersachsen Germany
| | - Oliver Schülke
- Department of Behavioural Ecology; University of Göttingen; Göttingen Niedersachsen Germany
- Primate Social Evolution Research Group; German Primate Center; Leibniz Institute for Primate Research; Göttingen Niedersachsen Germany
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Maag N, Cozzi G, Bateman A, Heistermann M, Ganswindt A, Manser M, Clutton-Brock T, Ozgul A. Cost of dispersal in a social mammal: body mass loss and increased stress. Proc Biol Sci 2019; 286:20190033. [PMID: 30963932 PMCID: PMC6408599 DOI: 10.1098/rspb.2019.0033] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2019] [Accepted: 01/16/2019] [Indexed: 01/12/2023] Open
Abstract
Dispersal is a key process influencing the dynamics of socially and spatially structured populations. Dispersal success is determined by the state of individuals at emigration and the costs incurred after emigration. However, quantification of such costs is often difficult, due to logistical constraints of following wide-ranging individuals. We investigated the effects of dispersal on individual body mass and stress hormone levels in a cooperative breeder, the meerkat ( Suricata suricatta). We measured body mass and faecal glucocorticoid metabolite (fGCM) concentrations from 95 dispersing females in 65 coalitions through the entire dispersal process. Females that successfully settled lost body mass, while females that did not settle but returned to their natal group after a short period of time did not. Furthermore, dispersing females had higher fGCM levels than resident females, and this was especially pronounced during the later stages of dispersal. By adding information on the transient stage of dispersal and by comparing dispersers that successfully settled to dispersers that returned to their natal group, we expand on previous studies focusing on the earlier stages of dispersal. We propose that body mass and stress hormone levels are good indicators to investigate dispersal costs, as these traits often play an important role in mediating the effects of the environment on other life-history events and individual fitness.
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Affiliation(s)
- Nino Maag
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
- Kalahari Research Centre, Kuruman River Reserve, Van Zylsrus 8467, South Africa
| | - Gabriele Cozzi
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
- Kalahari Research Centre, Kuruman River Reserve, Van Zylsrus 8467, South Africa
| | - Andrew Bateman
- Department of Geography, University of Victoria, 3800 Finnerty Road, Victoria, CanadaV8P 5C2
| | - Michael Heistermann
- Endocrinology Laboratory, German Primate Center, Leibniz Institute for Primate Research, Kellnerweg 4, 37077 Göttingen, Germany
| | - André Ganswindt
- Mammal Research Institute, University of Pretoria, cnr Lynnwood Road and Roper Street, Hatfield 0028, South Africa
| | - Marta Manser
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
- Kalahari Research Centre, Kuruman River Reserve, Van Zylsrus 8467, South Africa
| | - Tim Clutton-Brock
- Kalahari Research Centre, Kuruman River Reserve, Van Zylsrus 8467, South Africa
- Mammal Research Institute, University of Pretoria, cnr Lynnwood Road and Roper Street, Hatfield 0028, South Africa
- Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK
| | - Arpat Ozgul
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
- Kalahari Research Centre, Kuruman River Reserve, Van Zylsrus 8467, South Africa
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Thompson NA, Higham JP, Heistermann M, Vogel E, Cords M. Energy balance but not competitive environment corresponds with allostatic load during development in an Old World monkey. Horm Behav 2019; 108:30-41. [PMID: 30597140 DOI: 10.1016/j.yhbeh.2018.12.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 11/03/2018] [Accepted: 12/25/2018] [Indexed: 12/13/2022]
Abstract
Primates develop slowly relative to their body size, a pattern posited to result from ecological risk aversion. Little is known, however, about how energy balance contributes to allostatic load in juveniles. Using data collected over 8 consecutive months, we examined variation in energy balance (as measured by urinary C-peptide) and how energy balance, life history status, and social competition related to allostatic load (as measured by deviation from baseline fecal glucocorticoid metabolites, dfGCs) in 41 wild juvenile blue monkeys from 3 social groups. Juvenile energy balance was higher among females, when ripe fruit was more available, and when rainfall was lower. Energy balance, but not life history or competitive environments, predicted dfGC concentrations, such that juveniles generally had lower mean dfGCs when they had higher energy balance. An additional exploratory analysis of how dfGCs relate to social strategies revealed that subjects had lower dfGCs when they groomed less, and played more. Time spent grooming interacted with energy balance in predicting dfGC concentrations, so that individuals that groomed more actually had higher dfGCs when they had higher energy balance. Together these results reveal that energetic deficiencies are a true ecological risk factor in blue monkeys, and suggest that navigating the social environment via overt affiliative behavior is potentially both a stress-relieving and stress-inducing endeavor during development.
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Affiliation(s)
- Nicole A Thompson
- Columbia University, Department of Ecology, Evolution, and Environmental Biology, United States of America; New York Consortium in Evolutionary Primatology, United States of America.
| | - James P Higham
- New York Consortium in Evolutionary Primatology, United States of America; New York University, Department of Anthropology, United States of America
| | | | - Erin Vogel
- Rutgers University, Department of Anthropology, United States of America
| | - Marina Cords
- Columbia University, Department of Ecology, Evolution, and Environmental Biology, United States of America; New York Consortium in Evolutionary Primatology, United States of America
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Pokharel SS, Seshagiri PB, Sukumar R. Influence of the number of calves and lactating adult females in a herd on the adrenocortical activity of free-ranging Asian elephants. WILDLIFE RESEARCH 2019. [DOI: 10.1071/wr18163] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Abstract
ContextPhysiological stress has the potential to influence animal population persistence. The endangered Asian elephant (Elephas maximus) is involved in intense conflict with humans in many parts of its range, which likely leads to stress for individuals and groups, with consequences for population survival. Thus, it is important to understand how the elephants’ stress levels are influenced by socio-ecological factors when not directly exposed to human-induced threats, and to use this understanding to improve conservation and management strategies.
AimsThe present study was designed to provide baseline information on the link between socio-ecological factors and stress levels of undisturbed populations of elephants. The main aim was to determine the influence of a number of factors – herd size, season, number of calves and adult females present in a herd and their lactational status and body condition – on the adrenocortical activity of free-ranging adult female Asian elephants living in protected forests (without any direct exposure to human-induced threats), by measuring their faecal glucocorticoid metabolite (fGCM) levels.
MethodsA total of 145 fresh faecal samples were collected from 123 identified adult female elephants inhabiting Bandipur and Nagarahole National Parks of southern India, between the years 2013 and 2015. fGCM levels were measured by employing a group-specific standardised 11-oxoetiocholanolone enzyme immunoassay (EIA). A generalised linear mixed-effects model (GLMM) was used to assess the influence of socio-ecological factors on fGCM levels of adult female elephants.
Key resultsWhen fGCM levels were analysed with a GLMM, the following patterns were observed: fGCM levels were negatively correlated with the number of adult females (herd size) and positively correlated with the number of calves in a herd and active lactational status of an adult female. fGCM levels of adult female elephants were higher during the dry season (February to May) than wet season (August to December) and negatively correlated with body condition scores.
ConclusionsAdrenocortical activity of female elephants is significantly influenced by the number of calves and adult females present in the herd, seasonality and lactational status.
ImplicationsIt is important to consider the influence of multiple ecological and social correlates when assessing and interpreting the adrenocortical activity of Asian elephants. Our findings highlight the importance of maintaining the social structure of elephants in the wild to avoid detrimental effects on their physiological health. Insights from such assessments could be used to evaluate the stress in elephants that are involved in direct conflicts with humans to take appropriate management decisions for mitigating conflicts.
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Müller-Klein N, Heistermann M, Strube C, Morbach ZM, Lilie N, Franz M, Schülke O, Ostner J. Physiological and social consequences of gastrointestinal nematode infection in a nonhuman primate. Behav Ecol 2018. [DOI: 10.1093/beheco/ary168] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Affiliation(s)
- Nadine Müller-Klein
- Department for Behavioral Ecology, University of Göttingen, Göttingen, Germany
| | - Michael Heistermann
- Endocrinology Laboratory, German Primate Centre, Leibniz Institute for Primate Research, Göttingen, Germany
| | - Christina Strube
- Institute for Parasitology, Centre for Infection Medicine, University of Veterinary Medicine Hannover, Hanover, Germany
| | - Zina M Morbach
- Department for Behavioral Ecology, University of Göttingen, Göttingen, Germany
- Department of Life Sciences, University of Roehampton, Parkstead House, Whitelands, London, UK
| | - Navina Lilie
- Department for Behavioral Ecology, University of Göttingen, Göttingen, Germany
- Department for Animal Behaviour, Bielefeld University, Bielefeld, Germany
| | - Mathias Franz
- Department of Wildlife Diseases, Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany
| | - Oliver Schülke
- Department for Behavioral Ecology, University of Göttingen, Göttingen, Germany
- Primate Social Evolution, German Primate Centre, Leibniz Institute for Primate Research, Göttingen, Germany
| | - Julia Ostner
- Department for Behavioral Ecology, University of Göttingen, Göttingen, Germany
- Primate Social Evolution, German Primate Centre, Leibniz Institute for Primate Research, Göttingen, Germany
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Palme R. Non-invasive measurement of glucocorticoids: Advances and problems. Physiol Behav 2018; 199:229-243. [PMID: 30468744 DOI: 10.1016/j.physbeh.2018.11.021] [Citation(s) in RCA: 269] [Impact Index Per Article: 44.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 11/16/2018] [Accepted: 11/16/2018] [Indexed: 01/19/2023]
Abstract
Glucocorticoids (GCs; i.e. cortisol/corticosterone) are a central component of the stress response and thus their measurement is frequently used to evaluate the impact of stressful situations. Their metabolites from faeces of various animal species are more and more taken as a non-invasive aid to assess GC release and thus adrenocortical activity. The current literature review includes an extensive collection (1327 papers) and evaluation (see also Supplementary Tables) of the literature on faecal cortisol/corticosterone metabolite (FCM) analysis published to date. It aims at giving reference for researchers interested in implementing FCM analysis into their study or seeking to improve such methods by providing background knowledge on GC metabolism and excretion, conveying insights into methodological issues and stating caveats of FCM analysis and by highlighting prerequisites for and some examples of a successful application of such methods. Collecting faecal samples and analysing FCMs may appear simple and straightforward, but researchers have to select and apply methods correctly. They also need to be aware of the many pitfalls and potentially confounding factors and, last but not least, have to carefully interpret results. Applied properly, measurement of FCMs is a powerful non-invasive tool in a variety of research areas, such as (stress) biology, ethology, ecology, animal conservation and welfare, but also biomedicine.
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Affiliation(s)
- Rupert Palme
- Unit of Physiology, Pathophysiology and Experimental Endocrinology, Department of Biomedical Sciences, University of Veterinary Medicine, Veterinärplatz 1, 1210 Vienna, Austria.
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Pokharel SS, Singh B, Seshagiri PB, Sukumar R. Lower levels of glucocorticoids in crop‐raiders: diet quality as a potential ‘pacifier’ against stress in free‐ranging Asian elephants in a human‐production habitat. Anim Conserv 2018. [DOI: 10.1111/acv.12450] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- S. S. Pokharel
- Centre for Ecological Sciences Indian Institute of Science Bangalore India
| | - B. Singh
- Centre for Ecological Sciences Indian Institute of Science Bangalore India
| | - P. B. Seshagiri
- Department of Molecular Reproduction and Developmental Genetics Indian Institute of Science Bangalore India
| | - R. Sukumar
- Centre for Ecological Sciences Indian Institute of Science Bangalore India
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Medger K, Bennett NC, Lutermann H, Ganswindt A. Non-invasive assessment of glucocorticoid and androgen metabolite levels in cooperatively breeding Damaraland mole-rats (Fukomys damarensis). Gen Comp Endocrinol 2018; 266:202-210. [PMID: 29782838 DOI: 10.1016/j.ygcen.2018.05.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Revised: 05/08/2018] [Accepted: 05/17/2018] [Indexed: 10/16/2022]
Abstract
Dominant females of cooperative breeding species often use aggression to suppress reproduction of subordinate females, resulting in subordinates experiencing stress-related increases in glucocorticoid levels, which may cause reproductive down-regulation. This would suggest a general pattern with higher glucocorticoid levels in subordinate compared to dominant individuals; however, the opposite was found in a number of cooperatively breeding species. Furthermore, breeding females of the cooperatively breeding Damaraland mole-rats (Fukomys damarensis) exhibit very high androgen concentrations during the wet season, presumably to support their breeding monopoly. Hormone analysis in Damaraland mole-rats have typically been measured using plasma and urine, but faecal analysis offers additional advantages especially for field studies on this species. The present study examines the suitability of Damaraland mole-rat faecal samples for determining glucocorticoid metabolite (fGCM) and androgen metabolite (fAM) concentrations using enzyme immunoassays. Using these assays, we further evaluated the effects of breeding status on fGCM and fAM concentrations in wild-caught and captive Damaraland mole-rats. Wild-caught breeding and non-breeding males and females exhibited no differences in fAM concentrations. Immunoreactive fGCM concentrations were only high in male breeders and comparatively low in non-breeders and breeding females. Concentrations of fAMs and fGCMs were similar in captive males and females, but fAM concentrations were elevated in captive compared to wild-caught individuals, which may be related to a higher reproductive activity due to removal from the breeding female. The relatively uniform fAM and fGCM concentrations found in wild-caught mole-rats may be explained by a stable colony structure during the dry season during which this study was conducted. Limited dispersal opportunities result in lower aggression and stress levels within a colony and as a result lower fAM and fGCM concentrations.
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Affiliation(s)
- Katarina Medger
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa.
| | - Nigel C Bennett
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa; SARChI Chair of Mammal Behavioural Ecology and Physiology, Department of Zoology and Entomology, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Heike Lutermann
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Andre Ganswindt
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa; Endocrine Research Laboratory, Department of Anatomy and Physiology, Faculty of Veterinary Science, Private Bag X04, Onderstepoort 0110, South Africa
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Molina‐García L, Pérez JM, Sarasa M, Ureña‐Gutiérrez B, Espinosa J, Azorit C. HPLC-QTOF method for quantifying 11-ketoetiocholanolone, a cortisol metabolite, in ruminants' feces: Optimization and validation. Ecol Evol 2018; 8:9218-9228. [PMID: 30377495 PMCID: PMC6194299 DOI: 10.1002/ece3.4285] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Revised: 04/23/2018] [Accepted: 05/19/2018] [Indexed: 11/26/2022] Open
Abstract
Studies of animal ecology can benefit from a quantified understanding of eco-physiological processes and, in particular, of the physiological responses in free-ranging animals to potential stressors. The determination of fecal cortisol metabolites as a noninvasive method for monitoring stress has proved to be a powerful tool. High-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS) has emerged as the most accurate method for avoiding problems related to the nonspecificity of immunoassays. In this study, we optimize and validate a reliable method using HPLC-MS/MS for quantifying 11-ketoetiocholanolone (11-k), a representative fecal cortisol metabolite in ruminants. An appropriate extraction and purification procedure was developed taking into account the complex nature of feces. The final extract obtained was then analyzed with HPLC-MS/MS using a quadrupole-time-of-fly (QTOF) tandem mass spectrometer with an electrospray ionization interface operating in positive mode, which allowed an unequivocal determination of the metabolite due to its accurate mass capabilities. After rigorous optimization of both sample extraction and the HPLC-QTOF parameters, making use of feces from free-ranging Iberian ibex, ideal conditions were established. Matrix-matched standards were used to calibrate the method. The limit of detection and quantification was 13- and 40- ng/g, respectively. The validation of the method was performed with recoveries in the range of 85-110%, a figure much higher than the 60% obtained with the previous extraction methods used in our laboratory, and with relative standard deviations (RSDs) no higher than 15% for the complete analytical procedure, including extraction and analysis. The time required for the fecal 11-k analysis was greatly reduced in comparison with the previous work carried out in our laboratory. This is the first time that QTOF mass detection coupled with HPLC has been validated for 11-k quantification in feces from free-ranging ruminants such as Iberian ibex. Given the high selectivity and sensitivity attained, our method could become a useful tool for noninvasive stress quantification in ruminants.
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Affiliation(s)
- Lucía Molina‐García
- Department of Animal and Plant Biology, and EcologyUniversity of JaénJaénSpain
| | - Jesus M. Pérez
- Department of Animal and Plant Biology, and EcologyUniversity of JaénJaénSpain
| | - Mathieu Sarasa
- Fédération Nationale des Chasseurs (FNC)Issy‐les‐MoulineauxFrance
- Present address:
BEOPSToulouseFrance
| | | | - Jose Espinosa
- Department of Animal and Plant Biology, and EcologyUniversity of JaénJaénSpain
| | - Concepción Azorit
- Department of Animal and Plant Biology, and EcologyUniversity of JaénJaénSpain
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Bertocchi M, Pelizzone I, Parmigiani E, Ponzio P, Macchi E, Righi F, Di Girolamo N, Bigliardi E, Denti L, Bresciani C, Di Ianni F. Monitoring the reproductive activity in captive bred female ball pythons (P. regius) by ultrasound evaluation and noninvasive analysis of faecal reproductive hormone (progesterone and 17β-estradiol) metabolites trends. PLoS One 2018; 13:e0199377. [PMID: 29949610 PMCID: PMC6021098 DOI: 10.1371/journal.pone.0199377] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 06/06/2018] [Indexed: 11/28/2022] Open
Abstract
The royal python (Python regius) is commonly bred in captivity. To have a successful breeding season, accurate monitoring of the reproductive activity is necessary. The use of non-invasive monitoring methods in exotics is important in order to minimize stress. For this purpose ultrasound has been anecdotally used to monitor royal python reproductive activity. However, there is limited information regarding the reproductive cycle of this species. The aim of the present study is to monitor the female reproductive cycle of the royal python using ultrasonography and gonadal steroid metabolite measurements in the faeces. The reproductive activity of one hundred twenty-nine adult female P. regius was examined during two consecutive years. We performed brief scans on non-anaesthetized snakes using a portable ultrasound system and a 10–12 MHz linear array transducer (MyLab™ 30 Gold, Esaote). Ultrasound features, dimension and echogenicity of the reproductive structures were determined. During the second reproductive cycle, the hormonal profiles of 30 animals were also evaluated, with a monthly collection of faecal samples. These samples were classified according to reproductive stage, as identified by ultrasonographic examination, and the mean faecal progesterone and 17β-estradiol levels were calculated using the results from an enzyme-linked immunosorbent assay (ELISA). Progesterone levels increased during the reproductive cycle. Estradiol levels showed greater variability, although they appeared to increase before coupling when compared to the levels between coupling and egg laying. The present study suggests that it is possible to identify different phases in the female royal python reproductive cycle: anovulatory phase, transition, folliculogenesis and embryogenesis. Ultrasound is also useful for identifying follicular regression or slugs. Gonadal steroid metabolite measurements from the faeces could help integrate reproductive information. The use of ultrasonography in addition to the steroid metabolite measurement in the faeces gives an accurate picture of ovarian activity in captive adult female royal pythons.
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Affiliation(s)
- Mara Bertocchi
- Department of Veterinary Science, Università degli Studi di Parma, Via Del Taglio, Parma, Italy
| | | | - Enrico Parmigiani
- Department of Veterinary Science, Università degli Studi di Parma, Via Del Taglio, Parma, Italy
| | - Patrizia Ponzio
- Department of Veterinary Science, Università degli Studi di Torino, Via Leonardo da Vinci, Grugliasco (TO), Italy
| | - Elisabetta Macchi
- Department of Veterinary Science, Università degli Studi di Torino, Via Leonardo da Vinci, Grugliasco (TO), Italy
| | - Federico Righi
- Department of Veterinary Science, Università degli Studi di Parma, Via Del Taglio, Parma, Italy
| | - Nicola Di Girolamo
- Tai Wai Small Animal and Exotic Hospital, Lap Wo Building, Tai Wai, Sha Tin, Hong Kong
| | - Enrico Bigliardi
- Department of Veterinary Science, Università degli Studi di Parma, Via Del Taglio, Parma, Italy
- * E-mail:
| | - Laura Denti
- Department of Veterinary Science, Università degli Studi di Parma, Via Del Taglio, Parma, Italy
| | - Carla Bresciani
- Department of Veterinary Science, Università degli Studi di Parma, Via Del Taglio, Parma, Italy
| | - Francesco Di Ianni
- Department of Veterinary Science, Università degli Studi di Parma, Via Del Taglio, Parma, Italy
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Webber JT, Henley MD, Pretorius Y, Somers MJ, Ganswindt A. Changes in African Elephant (Loxodonta africana) faecal steroid concentrations post-defaecation. ACTA ACUST UNITED AC 2018. [DOI: 10.4102/abc.v48i2.2312] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
Background: Faecal hormone metabolite measurement is a widely used tool for monitoring reproductive function and response to stressors in wildlife. Despite many advantages of this technique, the delay between defaecation, sample collection and processing may influence steroid concentrations, as faecal bacterial enzymes can alter steroid composition post-defaecation.Objectives: This study investigated changes in faecal glucocorticoid (fGCM), androgen (fAM) and progestagen (fPM) metabolite concentrations in faeces of a male and female African elephant (Loxodonta africana) post-defaecation and the influence of different faeces-drying regimes.Method: Subsamples of fresh faeces were frozen after being dried in direct sun or shade for 6, 20, 24, 48 and 72 h and 7 and 34 days. A subset of samples for each sex was immediately frozen as controls. Faecal hormone metabolite concentrations were determined using enzyme immunoassays established for fGCM, fAM and fPM monitoring in male and female African elephants.Results: Hormone metabolite concentrations of all three steroid classes were stable at first, but changed distinctively after 20 h post-defaecation, with fGCM concentrations decreasing over time and fPM and fAM concentrations steadily increasing. In freeze-dried faeces fGCM concentrations were significantly higher than respective concentrations in sun-dried material, which were in turn significantly higher than fGCM concentrations in shade-dried material. In contrast, fAM concentrations were significantly higher in sun- and shade-dried faeces compared to freeze-dried faeces. Higher fPM concentrations were also found in air-dried samples compared to lyophilised faeces, but the effect was only significant for sun-dried material.Conclusion: The revealed time restriction for collecting faecal material for hormone monitoring from elephants in the wild should be taken into account to assure reliable and comparable results. However, if logistics allow a timely collection, non-invasive hormone measurement remains a powerful and reliable approach to provide information about an elephant’s endocrine status.
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Comparison of fecal preservation and extraction methods for steroid hormone metabolite analysis in wild crested macaques. Primates 2018; 59:281-292. [PMID: 29429140 DOI: 10.1007/s10329-018-0653-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 02/02/2018] [Indexed: 10/18/2022]
Abstract
Since the non-invasive field endocrinology techniques were developed, several fecal preservation and extraction methods have been established for a variety of species. However, direct adaptation of methods from previous studies for use in crested macaques should be taken with caution. We conducted an experiment to assess the accuracy and stability of fecal estrogen metabolite (E1C) and glucocorticoid metabolite (GCM) concentrations in response to several preservation parameters: (1) time lag between sample collection and fecal preservation; (2) long-term storage of fecal samples in 80% methanol (MeOH) at ambient temperature; (3) different degrees of feces drying temperature using a conventional oven; and (4) different fecal preservation techniques (i.e., freeze-drying, oven-drying, and field-friendly extraction method) and extraction solvents (methanol, ethanol, and commercial alcohol). The study used fecal samples collected from crested macaques (Macaca nigra) living in the Tangkoko Reserve, North Sulawesi, Indonesia. Samples were assayed using validated E1C and GCM enzyme immunoassays. Concentrations of E1C and GCM in unprocessed feces stored at ambient temperature remained stable for up to 8 h of storage after which concentrations of both E1C and GCM changed significantly compared to controls extracted at time 0. Long-term storage in 80% MeOH at ambient temperature affected hormone concentrations significantly with concentrations of both E1C and GCM increasing after 6 and 4 months of storage, respectively. Drying fecal samples using a conventional oven at 50, 70, and 90 °C did not affect the E1C concentrations, but led to a significant decline for GCM concentrations in samples dried at 90 °C. Different fecal preservation techniques and extraction solvents provided similar results for both E1C and GCM concentrations. Our results confirm previous studies that prior to application of fecal hormone analysis in a new species, several preservation parameters should be evaluated for their effects on hormone metabolite stability. The results also provide several options for fecal preservation, extraction, and storage methods that can be selected depending on the condition of the field site and laboratory.
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Milich KM, Georgiev AV, Petersen RM, Emery Thompson M, Maestripieri D. Alpha male status and availability of conceptive females are associated with high glucocorticoid concentrations in high-ranking male rhesus macaques (Macaca mulatta) during the mating season. Horm Behav 2018; 97:5-13. [PMID: 28954215 PMCID: PMC6180231 DOI: 10.1016/j.yhbeh.2017.09.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2016] [Revised: 09/18/2017] [Accepted: 09/22/2017] [Indexed: 11/29/2022]
Abstract
The relationship between male mating opportunities, stress, and glucocorticoid concentrations is complicated by the fact that physiological stress and glucocorticoid concentrations can be influenced by dominance rank, group size, and the stability of the male dominance hierarchy, along with ecological factors. We studied the three highest-ranking males in nine different social groups within the same free-ranging population of rhesus macaques on Cayo Santiago, Puerto Rico, during the mating season, to examine variation in glucocorticoid concentrations in relation to number of females that conceived each month, alpha status, number of adult males in a group, and male rank hierarchy stability. We found that glucocorticoid concentrations were highest in the early mating season period when more females conceived in each group and declined linearly as the mating season progressed and the number of conceptive females decreased. Alpha males had significantly higher mean monthly glucocorticoid concentrations than other high-ranking males throughout the study period. Male age, number of adult males in a group, and hierarchy stability were not significantly associated with glucocorticoid concentrations. Our findings suggest that alpha males may experience significantly higher levels of physiological stress than their immediate subordinates and that this stress coincides with the period of the mating season when most conceptions occur.
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Affiliation(s)
- Krista M Milich
- Institute for Mind and Biology, The University of Chicago, USA; Department of Anthropology, Washington University in St. Louis, USA.
| | - Alexander V Georgiev
- Institute for Mind and Biology, The University of Chicago, USA; School of Biological Sciences, Bangor University, UK
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Hunninck L, Ringstad IH, Jackson CR, May R, Fossøy F, Uiseb K, Killian W, Palme R, Røskaft E. Being stressed outside the park-conservation of African elephants ( Loxodonta africana) in Namibia. CONSERVATION PHYSIOLOGY 2017; 5:cox067. [PMID: 29270294 PMCID: PMC5734242 DOI: 10.1093/conphys/cox067] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 10/27/2017] [Accepted: 11/06/2017] [Indexed: 05/30/2023]
Abstract
The conservation of the African savanna elephant (Loxodonta africana) is of prime importance for many African countries. Interactions between elephants and humans are known to induce stress and thereby have the potential to affect elephants' fitness. In Namibia, anthropogenic disturbances are increasing due to increasing human population size and development, particularly near protected areas, such as national parks. In this study, we investigated elephant stress levels in relation to their land use, specifically their protection status, comparing elephants within Etosha National Park in Namibia with elephants residing outside the park. We noninvasively collected dung samples of 91 elephants and determined the concentration of faecal glucocorticoid metabolites (fGCM), an indicator of physiological stress. Elephants outside the park (N = 35) had significantly higher concentrations of fGCM than those inside ENP (N = 56), suggesting that, despite including community-based conservancies, unprotected areas are more stressful for elephants than protected areas, most likely due to increased interactions with humans. We also found that males had lower fGCM concentrations than females, but no significant effect of age, body size or group size was detected. Additionally, herd sizes were significantly smaller and calf recruitment was potentially lower in unprotected areas. These findings underpin the importance of protected areas such as ENP, while encouraging decision-makers to continue reducing and mitigating potential human-induced disturbances.
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Affiliation(s)
- Louis Hunninck
- Norwegian University of Science and Technology—NTNU, Department of Biology, Høgskoleringen 1, 7491 Trondheim, Norway
| | - Iris H Ringstad
- Norwegian University of Science and Technology—NTNU, Department of Biology, Høgskoleringen 1, 7491 Trondheim, Norway
| | - Craig R Jackson
- Norwegian Institute for Nature Research—NINA, Department of Terrestrial Ecology, Høgskoleringen 9, 7034 Trondheim, Norway
| | - Roel May
- Norwegian Institute for Nature Research—NINA, Department of Terrestrial Ecology, Høgskoleringen 9, 7034 Trondheim, Norway
| | - Frode Fossøy
- Norwegian University of Science and Technology—NTNU, Department of Biology, Høgskoleringen 1, 7491 Trondheim, Norway
- Norwegian Institute for Nature Research—NINA, Department of Terrestrial Ecology, Høgskoleringen 9, 7034 Trondheim, Norway
| | - Kenneth Uiseb
- Ministry of Environment and Tourism, Directorate of Scientific Services, P/Bag 13306, Windhoek, Namibia
| | - Werner Killian
- Ministry of Environment and Tourism, Directorate of Scientific Services, P/Bag 13306, Windhoek, Namibia
| | - Rupert Palme
- University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria
| | - Eivin Røskaft
- Norwegian University of Science and Technology—NTNU, Department of Biology, Høgskoleringen 1, 7491 Trondheim, Norway
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Burgess EA, Hunt KE, Kraus SD, Rolland RM. Adrenal responses of large whales: Integrating fecal aldosterone as a complementary biomarker to glucocorticoids. Gen Comp Endocrinol 2017; 252:103-110. [PMID: 28757434 DOI: 10.1016/j.ygcen.2017.07.026] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 07/18/2017] [Accepted: 07/25/2017] [Indexed: 10/19/2022]
Abstract
Until now, physiological stress assessment of large whales has predominantly focused on adrenal glucocorticoid (GC) measures. Elevated GC concentrations in feces (fGC) are known to reflect stressful disturbances, such as fishing gear entanglement and human-generated underwater noise, in North Atlantic right whales (Eubalaena glacialis). However, there can be considerable variation in GC production as a function of sex and life history stage, which may confound the interpretation of fGC levels. Additionally, GC antibodies used in immunoassays can cross-react with other fecal metabolites (i.e., non-target steroids), potentially influencing fGC data. Here, aldosterone concentrations (fALD; aldosterone and related metabolites) were measured in fecal samples from right whales (total n=315 samples), including samples from identified individuals of known life history (n=82 individual whales), to evaluate its utility as a complementary biomarker to fGC for identifying adrenal activation. Concentrations of fALD were positively correlated with fGCs in right whales (r=0.59, P<0.001), suggesting concurrent secretion of these hormones by the adrenal gland. However, fALD levels were less influenced by concentrations of reproductive steroids in feces, minimizing the potential confounder of assay cross-reactivity in samples with highly skewed hormone ratios. Across different life history states for right whales, fALD concentrations showed similar patterns to those reported for fGC, with higher levels in pregnant females (35.9±7.6ng/g) followed by reproductively mature males (9.5±0.9ng/g) (P<0.05), providing further evidence of elevated adrenal activation in these groups of whales. The addition of fALD measurement as a biomarker of adrenal activation may help distinguish between intrinsic and external causes of stress hormone elevations in large whales, as well as other free-living wildlife species, providing a more comprehensive approach for associating adrenal activation with specific natural and anthropogenic stressors.
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Affiliation(s)
- Elizabeth A Burgess
- Anderson Cabot Center for Ocean Life, New England Aquarium, 1 Central Wharf, Boston, MA 02110, United States.
| | - Kathleen E Hunt
- Anderson Cabot Center for Ocean Life, New England Aquarium, 1 Central Wharf, Boston, MA 02110, United States
| | - Scott D Kraus
- Anderson Cabot Center for Ocean Life, New England Aquarium, 1 Central Wharf, Boston, MA 02110, United States
| | - Rosalind M Rolland
- Anderson Cabot Center for Ocean Life, New England Aquarium, 1 Central Wharf, Boston, MA 02110, United States
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