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Robertson MR, Olivier LJ, Roberts J, Yonthantham L, Banda C, N’gombwa IB, Dale R, Tiller LN. Testing the Effectiveness of the "Smelly" Elephant Repellent in Controlled Experiments in Semi-Captive Asian and African Savanna Elephants. Animals (Basel) 2023; 13:3334. [PMID: 37958089 PMCID: PMC10647569 DOI: 10.3390/ani13213334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 10/12/2023] [Accepted: 10/19/2023] [Indexed: 11/15/2023] Open
Abstract
Crop-raiding by elephants is one of the most prevalent forms of human-elephant conflict and is increasing with the spread of agriculture into wildlife range areas. As the magnitude of conflicts between people and elephants increases across Africa and Asia, mitigating and reducing the impacts of elephant crop-raiding has become a major focus of conservation intervention. In this study, we tested the responses of semi-captive elephants to the "smelly" elephant repellent, a novel olfactory crop-raiding mitigation method. At two trial sites, in Zambia and Thailand, African elephants (Loxodonta africana) and Asian elephants (Elephas maximus) were exposed to the repellent, in order to test whether or not they entered an area protected by the repellent and whether they ate the food provided. The repellent elicited clear reactions from both study groups of elephants compared to control conditions. Generalised linear models revealed that the elephants were more alert, sniffed more, and vocalised more when they encountered the repellent. Although the repellent triggered a response, it did not prevent elephants from entering plots protected by the repellent or from eating crops, unlike in trials conducted with wild elephants. Personality played a role in responses towards the repellent, as the elephants that entered the experimental plots were bolder and more curious individuals. We conclude that, although captive environments provide controlled settings for experimental testing, the ecological validity of testing human-elephant conflict mitigation methods with captive wildlife should be strongly considered. This study also shows that understanding animal behaviour is essential for improving human-elephant coexistence and for designing deterrence mechanisms. Appreciating personality traits in elephants, especially amongst "problem" elephants who have a greater propensity to crop raid, could lead to the design of new mitigation methods designed to target these individuals.
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Affiliation(s)
| | - Lisa J. Olivier
- Game Rangers International, Plot 2374, The Village, Leopards Hill Road, Lusaka 10101, Zambia; (L.J.O.); (C.B.)
| | - John Roberts
- Golden Triangle Asian Elephant Foundation, 229 Moo 1, Chiang Saen, Chiang Rai 57150, Thailand; (J.R.); (L.Y.)
| | - Laddawan Yonthantham
- Golden Triangle Asian Elephant Foundation, 229 Moo 1, Chiang Saen, Chiang Rai 57150, Thailand; (J.R.); (L.Y.)
| | - Constance Banda
- Game Rangers International, Plot 2374, The Village, Leopards Hill Road, Lusaka 10101, Zambia; (L.J.O.); (C.B.)
| | - Innocent B. N’gombwa
- Department of National Parks and Wildlife, Ministry of Tourism, Chilanga 10101, Zambia;
| | - Rachel Dale
- Department for Psychosomatic Medicine and Psychotherapy, University for Continuing Education Krems, 3500 Krems an der Donau, Austria;
| | - Lydia N. Tiller
- Amboseli Trust for Elephants, Langata, Nairobi 15135, Kenya;
- Durrell Institute of Conservation and Ecology, University of Kent, Canterbury CT2 7NZ, UK
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2
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Lo Preti M, Beccai L. Sensorized objects used to quantitatively study distal grasping in the African elephant. iScience 2023; 26:107657. [PMID: 37744412 PMCID: PMC10517398 DOI: 10.1016/j.isci.2023.107657] [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: 02/10/2023] [Revised: 06/23/2023] [Accepted: 08/15/2023] [Indexed: 09/26/2023] Open
Abstract
Nature evolved many ways to grasp objects without using hands: elephants, octopuses, and monkeys use highly dexterous appendices. From a roboticist's perspective, the elephant trunk is a fascinating manipulator, which strategies can empower robots' interaction capabilities. However, quantifying prehensile forces in such large animals in a safe, ethical, and reproducible manner is challenging. We developed two sensorized objects to investigate the grasping of an adult African elephant with deliberately occluded vision. A cylinder and a handle provided a distributed force (80 and 6 taxels) and inertial measurements in real-time, resisting dirt and shocks. The animal curled the distal portion of the trunk to grasp the tools. Using force and contact area data of the cylinder revealed the animal's ability to finely modulate pressure. The handle data provided insights into the energy-efficient behavior of the animal, with no significant grasping force changes despite variations imposed on both weight (5-15 kg) and initial position of the object.
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Affiliation(s)
- Matteo Lo Preti
- Soft BioRobotics Perception Lab, Istituto Italiano di Tecnologia, 16163 Genova, Italy
- The BioRobotics Institute, Scuola Superiore Sant’Anna, 56025 Pontedera, Italy
| | - Lucia Beccai
- Soft BioRobotics Perception Lab, Istituto Italiano di Tecnologia, 16163 Genova, Italy
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3
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Nguyen VP, Dhyan SB, Mai V, Han BS, Chow WT. Bioinspiration and Biomimetic Art in Robotic Grippers. MICROMACHINES 2023; 14:1772. [PMID: 37763934 PMCID: PMC10535325 DOI: 10.3390/mi14091772] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 09/07/2023] [Accepted: 09/09/2023] [Indexed: 09/29/2023]
Abstract
The autonomous manipulation of objects by robotic grippers has made significant strides in enhancing both human daily life and various industries. Within a brief span, a multitude of research endeavours and gripper designs have emerged, drawing inspiration primarily from biological mechanisms. It is within this context that our study takes centre stage, with the aim of conducting a meticulous review of bioinspired grippers. This exploration involved a nuanced classification framework encompassing a range of parameters, including operating principles, material compositions, actuation methods, design intricacies, fabrication techniques, and the multifaceted applications into which these grippers seamlessly integrate. Our comprehensive investigation unveiled gripper designs that brim with a depth of intricacy, rendering them indispensable across a spectrum of real-world scenarios. These bioinspired grippers with a predominant emphasis on animal-inspired solutions have become pivotal tools that not only mirror nature's genius but also significantly enrich various domains through their versatility.
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Affiliation(s)
- Van Pho Nguyen
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore 639798, Singapore or (V.P.N.); (S.B.D.)
- Schaeffler Hub for Advanced Research at NTU, Singapore 637460, Singapore;
| | - Sunil Bohra Dhyan
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore 639798, Singapore or (V.P.N.); (S.B.D.)
- Schaeffler Hub for Advanced Research at NTU, Singapore 637460, Singapore;
| | - Vu Mai
- Faculty of Engineering, Dong Nai Technology University, Bien Hoa City 76000, Vietnam;
| | - Boon Siew Han
- Schaeffler Hub for Advanced Research at NTU, Singapore 637460, Singapore;
| | - Wai Tuck Chow
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore 639798, Singapore or (V.P.N.); (S.B.D.)
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4
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Chu PC, Wierucka K, Murphy D, Tilley HB, Mumby HS. Human interventions in a behavioural experiment for Asian Elephants (Elephas maximus). Anim Cogn 2023; 26:393-404. [PMID: 35987800 PMCID: PMC9392510 DOI: 10.1007/s10071-022-01668-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 07/21/2022] [Accepted: 08/01/2022] [Indexed: 11/30/2022]
Abstract
Experiments are widely used to investigate the behaviour and cognition of animals. While the automation of experiments to avoid potential experimenter bias is sometimes possible, not all experiments can be conducted without human presence. This is particularly true for large animals in captivity, which are often managed by professional handlers. For the safety of the animals and experimenters, a handler must be present during behavioural studies with certain species. It is not always clear to what extent cues provided by handlers affect the animals, and therefore the experimental results. In this study, we investigate handler interventions during the training process for a behavioural experiment with Asian elephants (Elephas maximus) in Nepal. We show that elephant handlers (mahouts) intervened to guide elephants in performing the learning task using vocal and behavioural cues, despite experimenters requesting minimal intervention. We found that although the frequency of mahout interventions did not decrease as the training progressed, the nature of their interventions changed. We also found more non-verbal than verbal cues across the training. Our results suggest that guidance from handlers may be common in behavioural studies, and continued consideration should be put into experimental design to reduce or account for cues that animals may receive from humans. This study also emphasises the need to take into account the presence of humans in interpreting the results of animal behavioural experiments, which not only presents challenges to behavioural research, but also represents opportunities for further study.
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Affiliation(s)
- Pui Ching Chu
- Area of Ecology and Biodiversity, School of Biological Sciences, University of Hong Kong, Pok Fu Lam, Hong Kong
| | - Kaja Wierucka
- Area of Ecology and Biodiversity, School of Biological Sciences, University of Hong Kong, Pok Fu Lam, Hong Kong
- Department of Anthropology, University of Zurich, Zurich, Switzerland
| | - Derek Murphy
- Area of Ecology and Biodiversity, School of Biological Sciences, University of Hong Kong, Pok Fu Lam, Hong Kong
- Cognitive Ethology Laboratory, German Primate Centre, Göttingen, Germany
| | - Hannah Bethany Tilley
- Area of Ecology and Biodiversity, School of Biological Sciences, University of Hong Kong, Pok Fu Lam, Hong Kong
| | - Hannah Sue Mumby
- Area of Ecology and Biodiversity, School of Biological Sciences, University of Hong Kong, Pok Fu Lam, Hong Kong.
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von Dürckheim KEM, Hoffman LC, Poblete-Echeverría C, Bishop JM, Goodwin TE, Schulte BA, Leslie A. A pachyderm perfume: odour encodes identity and group membership in African elephants. Sci Rep 2022; 12:16768. [PMID: 36202901 PMCID: PMC9537315 DOI: 10.1038/s41598-022-20920-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 09/20/2022] [Indexed: 11/09/2022] Open
Abstract
Group-living animals that live in complex social systems require effective modes of communication to maintain social cohesion, and several acoustic, olfactory and visual signaling systems have been described. Individuals need to discriminate between in- and out-group odour to both avoid inbreeding and to identify recipients for reciprocal behaviour. The presence of a unique group odour, identified in several social mammals, is a proposed mechanism whereby conspecifics can distinguish group from non-group members. African elephants (Loxodonta africana) live in stable, socially complex, multi-female, fission-fusion groups, characterized by female philopatry, male dispersal and linear dominance hierarchies. Elephant social behaviour suggests that individuals use odour to monitor the sex, reproductive status, location, health, identity and social status of conspecifics. To date, it is not clear what fixed or variable information is contained in African elephant secretions, and whether odour encodes kinship or group membership information. Here we use SPME GC-MS generated semiochemical profiles for temporal, buccal and genital secretions for 113 wild African elephants and test their relationship with measures of genetic relatedness. Our results reveal the existence of individual identity odour profiles in African elephants as well as a signature for age encoded in temporal gland and buccal secretions. Olfactory signatures for genetic relatedness were found in labial secretions of adult sisters. While group odour was not correlated with group genetic relatedness, our analysis identified "group membership" as a significant factor explaining chemical differences between social groups. Saturated and short-chain fatty acids (SCFAs), derived from key volatile compounds from bacterial fermentation, were identified in temporal, buccal and genital secretions suggesting that group odour in African elephants may be the result of bacterial elements of the gut microbiome. The frequent affiliative behavior of African elephants is posited as a likely mechanism for bacterial transmission. Our findings favour flexible group-specific bacterial odours, which have already been proposed for other social mammals and present a useful form of olfactory communication that promotes bond group cohesion among non-relatives in fission-fusion mammals.
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Affiliation(s)
- Katharina E M von Dürckheim
- Department of Conservation Ecology and Entomology, Faculty of AgriSciences, University of Stellenbosch, Stellenbosch, South Africa. .,Department of Animal Sciences, Faculty of AgriSciences, University of Stellenbosch, Stellenbosch, South Africa.
| | - Louwrens C Hoffman
- Department of Animal Sciences, Faculty of AgriSciences, University of Stellenbosch, Stellenbosch, South Africa.,Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation (QAAFI), The University of Queensland, Digital Agricultural Building, 8115, Office 110, Gatton, QLD, 4343, Australia
| | - Carlos Poblete-Echeverría
- Department of Viticulture and Oenology, Faculty of AgriSciences, University of Stellenbosch, Stellenbosch, South Africa
| | - Jacqueline M Bishop
- Institute for Communities and Wildlife in Africa, Department of Biological Sciences, University of Cape Town, Private Bag X3, Cape Town, 7701, South Africa
| | - Thomas E Goodwin
- Department of Chemistry, Hendrix College, Conway, AR, 72032, USA
| | - Bruce A Schulte
- Department of Biology, Western Kentucky University, 1906 College Heights Blvd., #11080, Bowling Green, KY, 42101-1080, USA
| | - Alison Leslie
- Department of Conservation Ecology and Entomology, Faculty of AgriSciences, University of Stellenbosch, Stellenbosch, South Africa
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Plotnik JM, Jacobson SL. A “thinking animal” in conflict: studying wild elephant cognition in the shadow of anthropogenic change. Curr Opin Behav Sci 2022. [DOI: 10.1016/j.cobeha.2022.101148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Acknowledging the Relevance of Elephant Sensory Perception to Human–Elephant Conflict Mitigation. Animals (Basel) 2022; 12:ani12081018. [PMID: 35454264 PMCID: PMC9031250 DOI: 10.3390/ani12081018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Revised: 04/11/2022] [Accepted: 04/12/2022] [Indexed: 02/05/2023] Open
Abstract
Simple Summary Elephants have a unique sensory perspective of the world, using their complex olfactory and auditory systems to make foraging and social decisions. All three species of elephants are endangered and inhabit environments, which are being affected rapidly by human development. Anthropogenic disturbances can have significant effects on elephants’ abilities to perceive sensory information and communicate with one another, potentially further endangering their survival. Conflicts over high-quality resources also arise from the overlapping habitation of humans and elephants. While many different methods have been employed to reduce this conflict, we propose that elephants’ unique olfactory and acoustic sensory strengths be considered in future mitigation strategies to achieve coexistence. Abstract Elephants are well known for their socio-cognitive abilities and capacity for multi-modal sensory perception and communication. Their highly developed olfactory and acoustic senses provide them with a unique non-visual perspective of their physical and social worlds. The use of these complex sensory signals is important not only for communication between conspecifics, but also for decisions about foraging and navigation. These decisions have grown increasingly risky given the exponential increase in unpredictable anthropogenic change in elephants’ natural habitats. Risk taking often develops from the overlap of human and elephant habitat in Asian and African range countries, where elephants forage for food in human habitat and crop fields, leading to conflict over high-quality resources. To mitigate this conflict, a better understanding of the elephants’ sensory world and its impact on their decision-making process should be considered seriously in the development of long-term strategies for promoting coexistence between humans and elephants. In this review, we explore the elephants’ sensory systems for audition and olfaction, their multi-modal capacities for communication, and the anthropogenic changes that are affecting their behavior, as well as the need for greater consideration of elephant behavior in elephant conservation efforts.
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8
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Soppelsa J, Pouydebat E, Lefeuvre M, Mulot B, Houssin C, Cornette R. The relationship between distal trunk morphology and object grasping in the African savannah elephant ( Loxodonta africana). PeerJ 2022; 10:e13108. [PMID: 35368332 PMCID: PMC8969868 DOI: 10.7717/peerj.13108] [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: 10/08/2021] [Accepted: 02/22/2022] [Indexed: 01/12/2023] Open
Abstract
Background During reach-to-grasp movements, the human hand is preshaped depending on the properties of the object. Preshaping may result from learning, morphology, or motor control variability and can confer a selective advantage on that individual or species. This preshaping ability is known in several mammals (i.e., primates, carnivores and rodents). However, apart from the tongue preshaping of lizards and chameleons, little is known about preshaping of other grasping appendages. In particular, the elephant trunk, a muscular hydrostat, has impressive grasping skills and thus is commonly called a hand. Data on elephant trunk grasping strategies are scarce, and nothing is known about whether elephants preshape their trunk tip according to the properties of their food. Methods To determine the influence of food sizes and shapes on the form of the trunk tip, we investigated the morphology of the distal part of the trunk during grasping movements. The influence of food item form on trunk tip shape was quantified in six female African savannah elephants (Loxodonta africana). Three food item types were presented to the elephants (elongated, flat, and cubic), as well as three different sizes of cubic items. A total of 107 ± 10 grips per individual were video recorded, and the related trunk tip shapes were recorded with a 2D geometric morphometric approach. Results Half of the individuals adjusted the shape of the distal part of their trunk according to the object type. Of the three elephants that did not preshape their trunk tip, one was blind and another was subadult. Discussion and perspectives We found that elephants preshaped their trunk tip, similar to the preshaping of other species' hands or paws during reach-to-grasp movements. This preshaping may be influenced by visual feedback and individual learning. To confirm these results, this study could be replicated with a larger sample of elephants.
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Affiliation(s)
- Julie Soppelsa
- Adaptive Mechanisms and Evolution (MECADEV), Centre national de la recherche scientifique/Muséum national d’Histoire naturelle, Paris, France
| | - Emmanuelle Pouydebat
- Adaptive Mechanisms and Evolution (MECADEV), Centre national de la recherche scientifique/Muséum national d’Histoire naturelle, Paris, France
| | - Maëlle Lefeuvre
- Institute of Environmental Sciences, Faculty of Biology, Jagiellonian University Cracow, Cracow, Poland
| | - Baptiste Mulot
- Zooparc de Beauval & Beauval Nature, Saint-Aignan, France
| | - Céline Houssin
- Institut de Systématique, Evolution, Biodiversité (ISYEB), Centre national de la recherche scientifique/ Muséum national d’Histoire naturelle, SU, EPHE, UA, Paris, France
| | - Raphaël Cornette
- Institut de Systématique, Evolution, Biodiversité (ISYEB), Centre national de la recherche scientifique/ Muséum national d’Histoire naturelle, SU, EPHE, UA, Paris, France
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9
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10
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Second-order characteristics don't favor a number-representing ANS. Behav Brain Sci 2021; 44:e184. [PMID: 34907869 DOI: 10.1017/s0140525x21000960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Clarke and Beck argue that the ANS doesn't represent non-numerical magnitudes because of its second-order character. A sensory integration mechanism can explain this character as well, provided the dumbbell studies involve interference from systems that segment by objects such as the Object Tracking System. Although currently equal hypotheses, I point to several ways the two can be distinguished.
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11
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Persistence is key: investigating innovative problem solving by Asian elephants using a novel multi-access box. Anim Cogn 2021; 25:657-669. [PMID: 34839408 DOI: 10.1007/s10071-021-01576-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 10/24/2021] [Accepted: 11/01/2021] [Indexed: 10/19/2022]
Abstract
Innovative problem solving is considered a hallmark measure of behavioral flexibility as it describes behavior by which an animal manipulates its environment in a novel way to reach a goal. Elephants are a highly social taxa that have demonstrated a remarkable capacity for adapting to changing environments. To understand how individual differences in behavior impact expressions of innovation, we used a novel extractive foraging device comprised of three compartments to evaluate innovation in 14 captive Asian elephants. In the first phase of testing, elephants had an opportunity to learn one solution, while the second phase gave them an opportunity to innovate to open two other compartments with different solutions. We measured the behavioral traits of neophilia, persistence, motivation, and exploratory diversity, and hypothesized that higher levels of each would be associated with more success in the second phase. Eight elephants innovated to solve three compartments, three solved two, and two solved only one. Consistent with studies in other species, we found that higher success was associated with greater persistence, but not with any other behavioral traits when analyzed per test session. Greater persistence and, unexpectedly, lower exploratory diversity, were associated with success when analyzed at the level of each individual door. Further work is needed to understand how innovation varies both within and between species, with particular attention to the potential impact of anthropogenic changes in wild environments.
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12
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Dagenais P, Hensman S, Haechler V, Milinkovitch MC. Elephants evolved strategies reducing the biomechanical complexity of their trunk. Curr Biol 2021; 31:4727-4737.e4. [PMID: 34428468 DOI: 10.1016/j.cub.2021.08.029] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 06/25/2021] [Accepted: 08/09/2021] [Indexed: 02/06/2023]
Abstract
The elephant proboscis (trunk), which functions as a muscular hydrostat with a virtually infinite number of degrees of freedom, is a spectacular organ for delicate to heavy object manipulation as well as social and sensory functions. Using high-resolution motion capture and functional morphology analyses, we show here that elephants evolved strategies that reduce the biomechanical complexity of their trunk. Indeed, our behavioral experiments with objects of various shapes, sizes, and weights indicate that (1) complex behaviors emerge from the combination of a finite set of basic movements; (2) curvature, torsion, and strain provide an appropriate kinematic representation, allowing us to extract motion primitives from the trunk trajectories; (3) transport of objects involves the proximal propagation of an inward curvature front initiated at the tip; (4) the trunk can also form pseudo-joints for point-to-point motion; and (5) the trunk tip velocity obeys a power law with its path curvature, similar to human hand drawing movements. We also reveal with unprecedented precision the functional anatomy of the African and Asian elephant trunks using medical imaging and macro-scale serial sectioning, thus drawing strong connections between motion primitives and muscular synergies. Our study is the first combined quantitative analysis of the mechanical performance, kinematic strategies, and functional morphology of the largest animal muscular hydrostat on Earth. It provides data for developing innovative "soft-robotic" manipulators devoid of articulations, replicating the high compliance, flexibility, and strength of the elephant trunk. VIDEO ABSTRACT.
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Affiliation(s)
- Paule Dagenais
- Laboratory of Artificial and Natural Evolution (LANE), Department of Genetics and Evolution, University of Geneva, 30, Quai Ernest-Ansermet, 1211 Geneva, Switzerland; SIB Swiss Institute of Bioinformatics, 30, Quai Ernest-Ansermet, 1211 Geneva, Switzerland
| | - Sean Hensman
- Adventure with Elephants, Bela Bela, South Africa
| | - Valérie Haechler
- Laboratory of Artificial and Natural Evolution (LANE), Department of Genetics and Evolution, University of Geneva, 30, Quai Ernest-Ansermet, 1211 Geneva, Switzerland
| | - Michel C Milinkovitch
- Laboratory of Artificial and Natural Evolution (LANE), Department of Genetics and Evolution, University of Geneva, 30, Quai Ernest-Ansermet, 1211 Geneva, Switzerland; SIB Swiss Institute of Bioinformatics, 30, Quai Ernest-Ansermet, 1211 Geneva, Switzerland.
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13
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Searching high and low: domestic dogs' understanding of solidity. Anim Cogn 2021; 25:555-570. [PMID: 34714437 DOI: 10.1007/s10071-021-01568-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 10/14/2021] [Accepted: 10/18/2021] [Indexed: 10/20/2022]
Abstract
Physical reasoning appears central to understanding how the world works, suggesting adaptive function across the animal kingdom. However, conclusive evidence for inferential reasoning about physical objects is limited to primates. We systematically tested a central feature-understanding of solidity-in domestic dogs, by adapting a validated procedure (the shelf task) previously used to test children and non-human primates. Dogs watched a treat dropped into an apparatus with a shelf either present (treat landing on the shelf) or absent (treat landing on the bottom surface) and chose where to search for it (above or below the shelf). Across four studies (n = 64), we manipulated visual access to the treat trajectory and apparatus interior. Dogs correctly inferred the location of treats using physical cues when the shelf was present (Study 1), and learned rapidly when visual cues of continuity were limited (Study 2), and when the shelf was absent (Study 3). Dogs were at chance when the apparatus was fully occluded, and the presence and absence of the shelf varied across trials within subjects, and showed no evidence of learning (Study 4). The findings of these four studies suggest that dogs may be able to make some inferences using solidity and continuity and do not exhibit proximity or gravity biases. However, dogs did not always search correctly from Trial 1, and failed to search correctly when the rewarded location varied within-subjects, suggesting a role for learning, and possible limits to their ability to make inferences about physical objects.
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Schulte BA, LaDue CA. The Chemical Ecology of Elephants: 21st Century Additions to Our Understanding and Future Outlooks. Animals (Basel) 2021; 11:2860. [PMID: 34679881 PMCID: PMC8532676 DOI: 10.3390/ani11102860] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 09/24/2021] [Accepted: 09/28/2021] [Indexed: 01/19/2023] Open
Abstract
Chemical signals are the oldest and most ubiquitous means of mediating intra- and interspecific interactions. The three extant species of elephants, the Asian elephant and the two African species, savanna and forest share sociobiological patterns in which chemical signals play a vital role. Elephants emit secretions and excretions and display behaviors that reveal the importance of odors in their interactions. In this review, we begin with a brief introduction of research in elephant chemical ecology leading up to the 21st century, and then we summarize the body of work that has built upon it and occurred in the last c. 20 years. The 21st century has expanded our understanding on elephant chemical ecology, revealing their use of odors to detect potential threats and make dietary choices. Furthermore, complementary in situ and ex situ studies have allowed the careful observations of captive elephants to be extended to fieldwork involving their wild counterparts. While important advances have been made in the 21st century, further work should investigate the roles of chemical signaling in elephants and how these signals interact with other sensory modalities. All three elephant species are threatened with extinction, and we suggest that chemical ecology can be applied for targeted conservation efforts.
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Affiliation(s)
- Bruce A. Schulte
- Department of Biology, Western Kentucky University, Bowling Green, KY 42101, USA
| | - Chase A. LaDue
- Department of Environmental Science and Policy, George Mason University, Fairfax, VA 22030, USA;
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15
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Li LL, Plotnik JM, Xia SW, Meaux E, Quan RC. Cooperating elephants mitigate competition until the stakes get too high. PLoS Biol 2021; 19:e3001391. [PMID: 34582437 PMCID: PMC8478180 DOI: 10.1371/journal.pbio.3001391] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 08/15/2021] [Indexed: 12/05/2022] Open
Abstract
Cooperation is ubiquitous in the animal kingdom as it aims to maximize benefits through joint action. Selection, however, may also favor competitive behaviors that could violate cooperation. How animals mitigate competition is hotly debated, with particular interest in primates and little attention paid thus far to nonprimates. Using a loose-string pulling apparatus, we explored cooperative and competitive behavior, as well as mitigation of the latter, in semi-wild Asian elephants (Elephas maximus). Our results showed that elephants first maintained a very high cooperation rate (average = 80.8% across 45 sessions). Elephants applied “block,” “fight back,” “leave,” “move side,” and “submission” as mitigation strategies and adjusted these strategies according to their affiliation and rank difference with competition initiators. They usually applied a “fight back” mitigation strategy as a sanction when competition initiators were low ranking or when they had a close affiliation, but were submissive if the initiators were high ranking or when they were not closely affiliated. However, when the food reward was limited, the costly competitive behaviors (“monopoly” and “fight”) increased significantly, leading to a rapid breakdown in cooperation. The instability of elephant cooperation as a result of benefit reduction mirrors that of human society, suggesting that similar fundamental principles may underlie the evolution of cooperation across species. This study shows that in a task requiring coordinated pulling, elephants compete for access to food but work to mitigate competition in order to maintain cooperation. If the cost of competition becomes too high, however, cooperation breaks down entirely. This behavior mirrors that seen in humans and other great apes, suggesting that certain cooperative mechanisms are not unique to primates.
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Affiliation(s)
- Li-Li Li
- Center for Integrative Conservation, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, China and Southeast Asia Biodiversity Research Institute, Chinese Academy of Sciences, Nay Pyi Taw, Myanmar
- University of Chinese Academy of Sciences, Beijing, China
| | - Joshua M. Plotnik
- Department of Psychology, Hunter College, City University of New York, New York, New York, United States of America
- Department of Psychology, The Graduate Center, City University of New York, New York, New York, United States of America
- * E-mail: (JMP); (R-CQ)
| | - Shang-Wen Xia
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, China
| | - Estelle Meaux
- Guangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning, Guangxi, China
| | - Rui-Chang Quan
- Center for Integrative Conservation, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, China and Southeast Asia Biodiversity Research Institute, Chinese Academy of Sciences, Nay Pyi Taw, Myanmar
- Center of Conservation Biology, Core Botanical Gardens, Chinese Academy of Sciences, Mengla, Yunnan, China
- * E-mail: (JMP); (R-CQ)
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16
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Lin FC, Whiting MJ, Hsieh MY, Shaner PJL, Lin SM. Superior continuous quantity discrimination in a freshwater turtle. Front Zool 2021; 18:49. [PMID: 34563231 PMCID: PMC8466656 DOI: 10.1186/s12983-021-00431-y] [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: 04/01/2021] [Accepted: 09/06/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Quantity discrimination, the ability to discriminate a magnitude of difference or discrete numerical information, plays a key role in animal behavior. While quantitative ability has been well documented in fishes, birds, mammals, and even in previously unstudied invertebrates and amphibians, it is still poorly understood in reptiles and has never been tested in an aquatic turtle despite the fact that evidence is accumulating that reptiles possess cognitive skills and learning ability. To help address this deficiency in reptiles, we investigated the quantitative ability of an Asian freshwater turtle, Mauremys sinensis, using red cubes on a white background in a trained quantity discrimination task. While spontaneous quantity discrimination methods are thought to be more ecologically relevant, training animals on a quantity discrimination task allows more comparability across taxa. RESULTS We assessed the turtles' quantitative performance in a series of tests with increasing quantity ratios and numerosities. Surprisingly, the turtles were able to discriminate quantities of up to 9 versus 10 (ratio = 0.9), which shows a good quantitative ability that is comparable to some endotherms. Our results showed that the turtles' quantitative performance followed Weber's law, in which success rate decreased with increasing quantity ratio across a wide range of numerosities. Furthermore, the gradual improvement of their success rate across different experiments and phases suggested that the turtles possess learning ability. CONCLUSIONS Reptile quantitative ability has long been ignored and therefore is likely under-estimated. More comparative research on numerical cognition across a diversity of species will greatly contribute to a clearer understanding of quantitative ability in animals and whether it has evolved convergently in diverse taxa.
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Affiliation(s)
- Feng-Chun Lin
- School of Life Science, National Taiwan Normal University, Taipei, Taiwan
| | - Martin J Whiting
- Department of Biological Sciences, Macquarie University, Sydney, NSW, Australia
| | | | - Pei-Jen Lee Shaner
- School of Life Science, National Taiwan Normal University, Taipei, Taiwan.
| | - Si-Min Lin
- School of Life Science, National Taiwan Normal University, Taipei, Taiwan.
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17
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Tollis M, Ferris E, Campbell MS, Harris VK, Rupp SM, Harrison TM, Kiso WK, Schmitt DL, Garner MM, Aktipis CA, Maley CC, Boddy AM, Yandell M, Gregg C, Schiffman JD, Abegglen LM. Elephant Genomes Reveal Accelerated Evolution in Mechanisms Underlying Disease Defenses. Mol Biol Evol 2021; 38:3606-3620. [PMID: 33944920 PMCID: PMC8383897 DOI: 10.1093/molbev/msab127] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Disease susceptibility and resistance are important factors for the conservation of endangered species, including elephants. We analyzed pathology data from 26 zoos and report that Asian elephants have increased neoplasia and malignancy prevalence compared with African bush elephants. This is consistent with observed higher susceptibility to tuberculosis and elephant endotheliotropic herpesvirus (EEHV) in Asian elephants. To investigate genetic mechanisms underlying disease resistance, including differential responses between species, among other elephant traits, we sequenced multiple elephant genomes. We report a draft assembly for an Asian elephant, and defined 862 and 1,017 conserved potential regulatory elements in Asian and African bush elephants, respectively. In the genomes of both elephant species, conserved elements were significantly enriched with genes differentially expressed between the species. In Asian elephants, these putative regulatory regions were involved in immunity pathways including tumor-necrosis factor, which plays an important role in EEHV response. Genomic sequences of African bush, forest, and Asian elephant genomes revealed extensive sequence conservation at TP53 retrogene loci across three species, which may be related to TP53 functionality in elephant cancer resistance. Positive selection scans revealed outlier genes related to additional elephant traits. Our study suggests that gene regulation plays an important role in the differential inflammatory response of Asian and African elephants, leading to increased infectious disease and cancer susceptibility in Asian elephants. These genomic discoveries can inform future functional and translational studies aimed at identifying effective treatment approaches for ill elephants, which may improve conservation.
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Affiliation(s)
- Marc Tollis
- School of Informatics, Computing, and Cyber Systems, Northern Arizona University, Flagstaff, AZ, USA
- Arizona Cancer Evolution Center, Arizona State University, Tempe, AZ, USA
| | - Elliott Ferris
- Department of Neurobiology and Anatomy, University of Utah, Salt Lake City, UT, USA
| | | | - Valerie K Harris
- Arizona Cancer Evolution Center, Arizona State University, Tempe, AZ, USA
- Center for Biocomputing, Security and Society, Biodesign Institute, Arizona State University, Tempe, AZ, USA
| | - Shawn M Rupp
- Arizona Cancer Evolution Center, Arizona State University, Tempe, AZ, USA
- Center for Biocomputing, Security and Society, Biodesign Institute, Arizona State University, Tempe, AZ, USA
| | - Tara M Harrison
- Arizona Cancer Evolution Center, Arizona State University, Tempe, AZ, USA
- Department of Clinical Sciences, North Carolina State University, Raleigh, NC, USA
| | - Wendy K Kiso
- Ringling Bros Center for Elephant Conservation, Polk City, FL, USA
| | - Dennis L Schmitt
- Ringling Bros Center for Elephant Conservation, Polk City, FL, USA
- William H. Darr College of Agriculture, Missouri State University, Springfield, MO, USA
| | | | - Christina Athena Aktipis
- Arizona Cancer Evolution Center, Arizona State University, Tempe, AZ, USA
- Department of Psychology, Arizona State University, Tempe, AZ, USA
| | - Carlo C Maley
- Arizona Cancer Evolution Center, Arizona State University, Tempe, AZ, USA
- Center for Biocomputing, Security and Society, Biodesign Institute, Arizona State University, Tempe, AZ, USA
| | - Amy M Boddy
- Arizona Cancer Evolution Center, Arizona State University, Tempe, AZ, USA
- Department of Anthropology, University of California, Santa Barbara, CA, USA
| | - Mark Yandell
- Department of Genetics, University of Utah, Salt Lake City, UT, USA
| | - Christopher Gregg
- Department of Neurobiology and Anatomy, University of Utah, Salt Lake City, UT, USA
| | - Joshua D Schiffman
- Arizona Cancer Evolution Center, Arizona State University, Tempe, AZ, USA
- Department of Pediatrics & Huntsman Cancer Institute, University of Utah, Salt Lake City, UT, USA
- PEEL Therapeutics, Inc., Salt Lake City, UT, USA & Haifa, Israel
| | - Lisa M Abegglen
- Arizona Cancer Evolution Center, Arizona State University, Tempe, AZ, USA
- Department of Pediatrics & Huntsman Cancer Institute, University of Utah, Salt Lake City, UT, USA
- PEEL Therapeutics, Inc., Salt Lake City, UT, USA & Haifa, Israel
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18
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Liehrmann O, Crawley JAH, Seltmann MW, Feillet S, Nyein UK, Aung HH, Htut W, Lahdenperä M, Lansade L, Lummaa V. Handler familiarity helps to improve working performance during novel situations in semi-captive Asian elephants. Sci Rep 2021; 11:15480. [PMID: 34326446 PMCID: PMC8322261 DOI: 10.1038/s41598-021-95048-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 07/19/2021] [Indexed: 11/12/2022] Open
Abstract
Working animals spend hours each day in close contact with humans and require training to understand commands and fulfil specific tasks. However, factors driving cooperation between humans and animals are still unclear, and novel situations may present challenges that have been little-studied to-date. We investigated factors driving cooperation between humans and animals in a working context through behavioural experiments with 52 working semi-captive Asian elephants. Human-managed Asian elephants constitute approximately a third of the remaining Asian elephants in the world, the majority of which live in their range countries working alongside traditional handlers. We investigated how the familiarity and experience of the handler as well as the elephant's age and sex affected their responses when asked to perform a basic task and to cross a novel surface. The results highlighted that when novelty is involved in a working context, an elephant's relationship length with their handler can affect their cooperation: elephants who had worked with their handler for over a year were more willing to cross the novel surface than those who had a shorter relationship with their handler. Older animals also tended to refuse to walk on the novel surface more but the sex did not affect their responses. Our study contributes much needed knowledge on human-working animal relationships which should be considered when adjusting training methods and working habits.
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Affiliation(s)
- Océane Liehrmann
- Department of Biology, University of Turku, 20500, Turku, Finland.
| | | | | | - Sherine Feillet
- Department of Biology, University of Turku, 20500, Turku, Finland
- Université Sorbonne Paris Nord, 93430, Villetaneuse, France
| | - U Kyaw Nyein
- Myanma Timber Enterprise, Gyogone Forest Compound, Bayint Naung Road, Insein Township, Yangon, 11011, Myanmar
| | - Htoo Htoo Aung
- Myanma Timber Enterprise, Gyogone Forest Compound, Bayint Naung Road, Insein Township, Yangon, 11011, Myanmar
| | - Win Htut
- Myanma Timber Enterprise, Gyogone Forest Compound, Bayint Naung Road, Insein Township, Yangon, 11011, Myanmar
| | - Mirkka Lahdenperä
- Department of Public Health, University of Turku and Turku University Hospital, 20520, Turku, Finland
| | - Léa Lansade
- CNRS, IFCE, INRAE, Université de Tours, PRC, 37380, Nouzilly, France
| | - Virpi Lummaa
- Department of Biology, University of Turku, 20500, Turku, Finland
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19
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20
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Abstract
On a now orthodox view, humans and many other animals possess a "number sense," or approximate number system (ANS), that represents number. Recently, this orthodox view has been subject to numerous critiques that question whether the ANS genuinely represents number. We distinguish three lines of critique-the arguments from congruency, confounds, and imprecision-and show that none succeed. We then provide positive reasons to think that the ANS genuinely represents numbers, and not just non-numerical confounds or exotic substitutes for number, such as "numerosities" or "quanticals," as critics propose. In so doing, we raise a neglected question: numbers of what kind? Proponents of the orthodox view have been remarkably coy on this issue. But this is unsatisfactory since the predictions of the orthodox view, including the situations in which the ANS is expected to succeed or fail, turn on the kind(s) of number being represented. In response, we propose that the ANS represents not only natural numbers (e.g. 7), but also non-natural rational numbers (e.g. 3.5). It does not represent irrational numbers (e.g. √2), however, and thereby fails to represent the real numbers more generally. This distances our proposal from existing conjectures, refines our understanding of the ANS, and paves the way for future research.
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21
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Snyder RJ, Barrett LP, Emory RA, Perdue BM. Performance of Asian elephants (Elephas maximus) on a quantity discrimination task is similar to that of African savanna elephants (Loxodonta africana). Anim Cogn 2021; 24:1121-1131. [PMID: 33811595 DOI: 10.1007/s10071-021-01504-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 01/24/2021] [Accepted: 03/08/2021] [Indexed: 02/04/2023]
Abstract
Using an object-choice task, we measured the relative quantity discrimination ability of Asian elephants. Two zoo-housed elephants were given auditory cues of food being dropped into two containers (Nonvisible condition), and in one condition they could also see the food on top of the containers (Visible condition). Elephants received sets of varying ratios and magnitudes. We found that the elephants chose the greater quantity of food significantly above chance in both the Visible and Nonvisible conditions. Additionally, we found the elephants' ability to discriminate between quantities decreased as the ratio, and not the absolute difference, between the quantities increased, which is predicted by the accumulator model. We also compare our findings to those from a study using the same methods with African savanna elephants and found that the two species performed at similar levels, but given our small sample size it is difficult to make strong species-level conclusions. In discussing our results, we consider differences between the two species' wild environments as well as the types of sensory cues provided in human care, and we provide recommendations for extensions of this work.
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Affiliation(s)
- Rebecca J Snyder
- Oklahoma City Zoo, 2000 Remington Way, Oklahoma City, OK, 73111, USA.
| | - Lisa P Barrett
- Oklahoma City Zoo, 2000 Remington Way, Oklahoma City, OK, 73111, USA
| | - Rachel A Emory
- Oklahoma City Zoo, 2000 Remington Way, Oklahoma City, OK, 73111, USA
| | - Bonnie M Perdue
- Agnes Scott College, 141 E. College Avenue, Decatur, GA, 30030, USA
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22
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Abstract
Social cooperation in rodents was recently validated in rats, and we recently successfully applied a modified automated analysis to mice. Here, we describe a detailed procedure for using this paradigm in mice that relies on reward-based mutual communication that is automatically detected by a software algorithm embedded in the custom-made equipment. We also describe exemplary results of analyses in mice as a guide to broader neuroscience research applications employing transgenic knockout mice modeling neuropsychiatric disorders and mice of various ages. For complete details on the use and execution of this protocol, please refer to Han et al. (2020). Detailed protocol for performing customized social cooperation tests in mice Detailed guidelines for analyzing social cooperation in mice Troubleshooting of the most common pitfalls associated with the procedure
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Affiliation(s)
- Jungsu Shin
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Korea
| | - Jaewon Ko
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Korea
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23
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The olfactory capability of dogs to discriminate between different quantities of food. Learn Behav 2021; 49:321-329. [PMID: 33620699 DOI: 10.3758/s13420-021-00463-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/11/2021] [Indexed: 11/08/2022]
Abstract
A previous study failed to find evidence that dogs could use olfactory cues to discriminate between 1 and 5 hot dog slices presented on a single trial (Horowitz et al., Learning and Motivation, 44, 207-217, 2013). In the experiments reported here, multiple trials were used to test dogs' ability to use olfaction to choose one of two opaque containers under which a larger number of food items was placed. In Experiment 1, dogs chose between 1 and 5 hot dog slices. In Experiments 2 and 3, we examined dogs' ability to discriminate between numbers of hot dog slices that varied in the numerical distance and the ratio between the smaller and larger quantities. Experiment 4 explored olfactory discrimination between quantities of a different food, dog kibble. Experiments 1-3 all showed that dogs used olfactory stimuli to choose the larger number of hot dog slices, but Experiments 2 and 3 revealed no effects of distance or ratio between numerical quantities. In Experiment 4, dogs failed to discriminate between 1 and 5 pieces of dog kibble. Factors that allow dogs to use olfactory cues to discriminate between quantities are discussed.
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24
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Prey quantity discrimination and social experience affect foraging decisions of rock lizards. Behav Ecol Sociobiol 2021. [DOI: 10.1007/s00265-021-02979-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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25
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Tan WH, Hii A, Solana‐Mena A, Wong EP, Loke VPW, Tan ASL, Kromann‐Clausen A, Hii N, bin Pura P, bin Tunil MT, A/L Din S, Chin CF, Campos‐Arceiz A. Long‐term monitoring of seed dispersal by Asian elephants in a Sundaland rainforest. Biotropica 2021. [DOI: 10.1111/btp.12889] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Wei Harn Tan
- School of Environmental and Geographical Sciences The University of Nottingham Malaysia Kajang Malaysia
| | - Adeline Hii
- School of Environmental and Geographical Sciences The University of Nottingham Malaysia Kajang Malaysia
| | - Alicia Solana‐Mena
- School of Environmental and Geographical Sciences The University of Nottingham Malaysia Kajang Malaysia
| | - Ee Phin Wong
- School of Environmental and Geographical Sciences The University of Nottingham Malaysia Kajang Malaysia
- Management & Ecology of Malaysian Elephants University of Nottingham Malaysia Semenyih Malaysia
| | - Vivienne P. W. Loke
- School of Environmental and Geographical Sciences The University of Nottingham Malaysia Kajang Malaysia
| | - Ange S. L. Tan
- School of Environmental and Geographical Sciences The University of Nottingham Malaysia Kajang Malaysia
| | - Anders Kromann‐Clausen
- School of Environmental and Geographical Sciences The University of Nottingham Malaysia Kajang Malaysia
| | - Ning Hii
- School of Environmental and Geographical Sciences The University of Nottingham Malaysia Kajang Malaysia
| | - Param bin Pura
- School of Environmental and Geographical Sciences The University of Nottingham Malaysia Kajang Malaysia
| | - Muhamad Tauhid bin Tunil
- School of Environmental and Geographical Sciences The University of Nottingham Malaysia Kajang Malaysia
| | - Sudin A/L Din
- School of Environmental and Geographical Sciences The University of Nottingham Malaysia Kajang Malaysia
| | - Chiew Foan Chin
- School of Biosciences The University of Nottingham Malaysia Kajang Malaysia
| | - Ahimsa Campos‐Arceiz
- School of Environmental and Geographical Sciences The University of Nottingham Malaysia Kajang Malaysia
- Southeast Asia Biodiversity Research Institute Chinese Academy of Sciences Nay Pyi Taw Myanmar
- Center for Integrative Conservation Xishuangbanna Tropical Botanical GardenChinese Academy of Sciences Mengla China
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26
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Jim HL, Range F, Marshall-Pescini S, Dale R, Plotnik JM. Investigating Indirect and Direct Reputation Formation in Asian Elephants ( Elephas maximus). Front Psychol 2021; 11:604372. [PMID: 33519611 PMCID: PMC7841644 DOI: 10.3389/fpsyg.2020.604372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Accepted: 11/17/2020] [Indexed: 11/17/2022] Open
Abstract
Reputation is a key component in social interactions of group-living animals and appears to play a role in the establishment of cooperation. Animals can form a reputation of an individual by directly interacting with them or by observing them interact with a third party, i.e., eavesdropping. Elephants are an interesting taxon in which to investigate eavesdropping as they are highly cooperative, large-brained, long-lived terrestrial mammals with a complex social organisation. The aim of this study was to investigate whether captive Asian elephants (Elephas maximus) could form reputations of humans through indirect and/or direct experience in two different paradigms: (1) a cooperative string-pulling task and (2) a scenario requiring begging. Fourteen captive Asian elephants in Thailand participated in an experimental procedure that consisted of three parts: baseline, observation, and testing. In the observation phase, the subject saw a conspecific interact with two people-one cooperative/generous and one non-cooperative/selfish. The observer could then choose which person to approach in the test phase. The elephants were tested in a second session 2-5 days later. We found no support for the hypothesis that elephants can form reputations of humans through indirect or direct experience, but these results may be due to challenges with experimental design rather than a lack of capacity. We discuss how the results may be due to a potential lack of ecological validity in this study and the difficulty of assessing motivation and attentiveness in elephants. Furthermore, we highlight the importance of designing future experiments that account for the elephants' use of multimodal sensory information in their decision-making.
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Affiliation(s)
- Hoi-Lam Jim
- Domestication Lab, Department of Interdisciplinary Life Sciences, Konrad Lorenz Institute of Ethology, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Friederike Range
- Domestication Lab, Department of Interdisciplinary Life Sciences, Konrad Lorenz Institute of Ethology, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Sarah Marshall-Pescini
- Domestication Lab, Department of Interdisciplinary Life Sciences, Konrad Lorenz Institute of Ethology, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Rachel Dale
- Domestication Lab, Department of Interdisciplinary Life Sciences, Konrad Lorenz Institute of Ethology, University of Veterinary Medicine Vienna, Vienna, Austria
- Department for Psychotherapy and Biopsychosocial Health, Danube University Krems, Krems, Austria
| | - Joshua M. Plotnik
- Department of Psychology, Hunter College, City University of New York, New York, NY, United States
- Department of Psychology, The Graduate Center, City University of New York, New York, NY, United States
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27
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Valenta K, Schmitt MH, Ayasse M, Nevo O. The sensory ecology of fear: African elephants show aversion to olfactory predator signals. CONSERVATION SCIENCE AND PRACTICE 2020. [DOI: 10.1111/csp2.333] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Affiliation(s)
- Kim Valenta
- Department of Anthropology University of Florida Gainesville Florida USA
| | - Melissa H. Schmitt
- Department of Ecology Evolution and Marine Biology University of California Santa Barbara Santa Barbara California USA
- South African Environmental Observation Network, Ndlovu Node Phalaborwa South Africa
| | - Manfred Ayasse
- Ulm University, Institute of Evolutionary Ecology and Conservation Genomics Ulm Germany
| | - Omer Nevo
- Ulm University, Institute of Evolutionary Ecology and Conservation Genomics Ulm Germany
- German Centre for Integrative Biodiversity Research (iDiv) Halle‐Jena‐Leipzig Leipzig Germany
- Friedrich Schiller University Jena, Institute of Biodiversity Jena Germany
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28
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Birch J, Schnell AK, Clayton NS. Dimensions of Animal Consciousness. Trends Cogn Sci 2020; 24:789-801. [PMID: 32830051 PMCID: PMC7116194 DOI: 10.1016/j.tics.2020.07.007] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 07/21/2020] [Accepted: 07/23/2020] [Indexed: 01/29/2023]
Abstract
How does consciousness vary across the animal kingdom? Are some animals 'more conscious' than others? This article presents a multidimensional framework for understanding interspecies variation in states of consciousness. The framework distinguishes five key dimensions of variation: perceptual richness, evaluative richness, integration at a time, integration across time, and self-consciousness. For each dimension, existing experiments that bear on it are reviewed and future experiments are suggested. By assessing a given species against each dimension, we can construct a consciousness profile for that species. On this framework, there is no single scale along which species can be ranked as more or less conscious. Rather, each species has its own distinctive consciousness profile.
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Affiliation(s)
- Jonathan Birch
- Centre for Philosophy of Natural and Social Science, London School of Economics and Political Science, Houghton Street, London, WC2A 2AE, UK.
| | - Alexandra K Schnell
- Comparative Cognition Lab, Department of Psychology, University of Cambridge, Cambridge CB2 3EB, UK
| | - Nicola S Clayton
- Comparative Cognition Lab, Department of Psychology, University of Cambridge, Cambridge CB2 3EB, UK
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29
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Nevo O, Schmitt MH, Ayasse M, Valenta K. Sweet tooth: Elephants detect fruit sugar levels based on scent alone. Ecol Evol 2020; 10:11399-11407. [PMID: 33144973 PMCID: PMC7593167 DOI: 10.1002/ece3.6777] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 08/07/2020] [Accepted: 08/18/2020] [Indexed: 11/10/2022] Open
Abstract
The ability to assess food quality is crucial to all organisms. Fleshy fruits are a major source of nutrients to various animals, and unlike most food sources, have evolved to be attractive and to be consumed by animals to promote seed dispersal. It has recently been established that fruit scent-the bouquet of volatile chemicals emitted by ripe fruit-is an evolved communication system between plants and animals. Further, it has been argued that chemicals that are synthesized from sugar and its products may be an honest signal for sugar content and fruit quality. Elephants are important seed dispersers for numerous species and possess an olfactory system that is likely to outperform most other animals. We tested the hypothesis that fruit scent signifies sugar content and that elephants are capable of assessing fruit sugar levels based on scent alone. Using a paired-choice test of marula fruits (Sclerocarya birrea) by semitame African elephants, we show that elephants are capable of identifying more sugar-rich fruits based on scent alone and that this is likely based on two chemical compounds: ethanol and ethyl acetate, both downstream products of sugar fermentation. These results shed light on the mechanisms driving elephant feeding ecology, plant signaling, and the coevolutionary process between angiosperms and animal seed dispersers.
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Affiliation(s)
- Omer Nevo
- Institute of Evolutionary Ecology and Conservation GenomicsUlm UniversityUlmGermany
- German Centre for Integrative Biodiversity Research (iDiv) Halle‐Jena‐LeipzigLeipzigGermany
- Institute of BiodiversityFriedrich Schiller University JenaJenaGermany
| | - Melissa H. Schmitt
- Department of Ecology, Evolution, and Marine BiologyUniversity of California Santa BarbaraSanta BarbaraCAUSA
- South African Environmental Observation NetworkNdlovu NodePhalaborwaSouth Africa
| | - Manfred Ayasse
- Institute of Evolutionary Ecology and Conservation GenomicsUlm UniversityUlmGermany
| | - Kim Valenta
- Department of AnthropologyUniversity of FloridaGainesvilleFLUSA
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30
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DiPaola JD, Yindee M, Plotnik JM. Investigating the use of sensory information to detect and track prey by the Sunda pangolin (Manis javanica) with conservation in mind. Sci Rep 2020; 10:9787. [PMID: 32555311 PMCID: PMC7300028 DOI: 10.1038/s41598-020-65898-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 05/11/2020] [Indexed: 11/16/2022] Open
Abstract
Pangolins are of conservation concern as one of the most heavily poached, yet least understood mammals. The Sunda pangolin (Manis javanica) in particular is a critically endangered species. Here, we investigate the behaviour of these pangolins, for the first time, using a battery of cognitive tasks based on a manipulation of available sensory information. In an object-choice task in which only one of two containers was baited with food, the pangolins were able to find the food with olfactory information alone (N = 2), but not with visual or acoustic information alone (N = 1). The single subject tested on all three domains was further tested on how he used smell to find food by providing him with an opportunity to find it from a controlled distance or by using scent trails as a guide. The results suggest that our subject may have the capacity to exploit scent trails left by prey which can be tracked to a final source, though we found no evidence to suggest that he had the ability to initiate hunts based on distant prey odors. Despite the small sample size, this is the first controlled experiment to investigate pangolin foraging behaviour and cognition, which may have implications for the future protection of pangolin habitat based on the location of prey species.
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Affiliation(s)
- Joshua D DiPaola
- Animal Behavior and Conservation Program, Department of Psychology, Hunter College, City University of New York, 695 Park Avenue, Room 611N, New York, NY, 10065, USA
| | - Marnoch Yindee
- Livestock and Wildlife Hospital, Faculty of Veterinary Science, Mahidol University, 199 Moo 9, Highway No. 323, Sai Yok, Kanchanaburi, 71150, Thailand.,Akkharatchakumari Veterinary College, Walailak University, 222 Thaiburi, Thasala, Nakhon Si Thammarat, 80161, Thailand
| | - Joshua M Plotnik
- Animal Behavior and Conservation Program, Department of Psychology, Hunter College, City University of New York, 695 Park Avenue, Room 611N, New York, NY, 10065, USA. .,Psychology Program, The Graduate Center, City University of New York, 365 Fifth Avenue, New York, NY, 10016, USA.
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Janiak MC, Pinto SL, Duytschaever G, Carrigan MA, Melin AD. Genetic evidence of widespread variation in ethanol metabolism among mammals: revisiting the 'myth' of natural intoxication. Biol Lett 2020; 16:20200070. [PMID: 32343936 DOI: 10.1098/rsbl.2020.0070] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Humans have a long evolutionary relationship with ethanol, pre-dating anthropogenic sources, and possess unusually efficient ethanol metabolism, through a mutation that evolved in our last common ancestor with African great apes. Increased exposure to dietary ethanol through fermenting fruits and nectars is hypothesized to have selected for this in our lineage. Yet, other mammals have frugivorous and nectarivorous diets, raising the possibility of natural ethanol exposure and adaptation in other taxa. We conduct a comparative genetic analysis of alcohol dehydrogenase class IV (ADH IV) across mammals to provide insight into their evolutionary history with ethanol. We find genetic variation and multiple pseudogenization events in ADH IV, indicating the ability to metabolize ethanol is variable. We suggest that ADH enzymes are evolutionarily plastic and show promise for revealing dietary adaptation. We further highlight the derived condition of humans and draw attention to problems with modelling the physiological responses of other mammals on them, a practice that has led to potentially erroneous conclusions about the likelihood of natural intoxication in wild animals. It is a fallacy to assume that other animals share our metabolic adaptations, rather than taking into consideration each species' unique physiology.
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Affiliation(s)
- Mareike C Janiak
- Department of Anthropology and Archaeology, University of Calgary, 2500 University Dr NW, Calgary AB T2N 1N4, Canada.,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada
| | - Swellan L Pinto
- Department of Anthropology and Archaeology, University of Calgary, 2500 University Dr NW, Calgary AB T2N 1N4, Canada
| | - Gwen Duytschaever
- Department of Anthropology and Archaeology, University of Calgary, 2500 University Dr NW, Calgary AB T2N 1N4, Canada
| | | | - Amanda D Melin
- Department of Anthropology and Archaeology, University of Calgary, 2500 University Dr NW, Calgary AB T2N 1N4, Canada.,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada.,Department of Medical Genetics, University of Calgary, AB, Canada
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Hedwig D, Verahrami AK, Wrege PH. Acoustic structure of forest elephant rumbles: a test of the ambiguity reduction hypothesis. Anim Cogn 2019; 22:1115-1128. [PMID: 31535246 DOI: 10.1007/s10071-019-01304-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 08/13/2019] [Accepted: 08/31/2019] [Indexed: 11/27/2022]
Abstract
Quantitative assessments of the structure of vocalizations are a fundamental prerequisite to understand a species' vocal communication system and, more broadly, the selective pressures shaping vocal repertoires. For example, to reduce ambiguity in signal interpretation in the absence of auxiliary visual cues, species in densely vegetated habitats should exhibit more discrete vocal signals than species in open habitats. To test this "ambiguity reduction hypothesis", we conducted the first quantitative assessment of the rumble vocalizations of the forest elephant. Based on 686 forest elephant rumbles recorded with autonomous acoustic recording units at four sites across Central Africa, we used model-based cluster analyses paired with subsequent evaluation of cluster-discreteness and discriminant function analyses to quantify the structure of rumbles based on 23 source- and filter-related acoustic parameters. Model-based cluster analyses suggest that rumbles can be classified into five to eight types. Similar to previous findings in savannah elephants and contrary to the ambiguity reduction hypothesis, average silhouette coefficients below 0.34 indicated that these rumble types were highly intergraded. However, discriminant function analyses predicted rumble types with at least 75% accuracy whereby the location of the minimum fundamental frequency, middle slope and peak frequency contributed most to separation between types. In line with an increasing number of studies highlighting that a distinction between discrete and graded repertoires may have little biological significance, we propose that ambiguity reduction may take place through the evolution of perceptual and cognitive mechanisms, rather than acting on vocal production.
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Affiliation(s)
- Daniela Hedwig
- Elephant Listening Project, Center for Conservation Bioacoustics, Cornell Lab of Ornithology, Cornell University, Ithaca, USA.
| | - Anahita K Verahrami
- Elephant Listening Project, Center for Conservation Bioacoustics, Cornell Lab of Ornithology, Cornell University, Ithaca, USA
| | - Peter H Wrege
- Elephant Listening Project, Center for Conservation Bioacoustics, Cornell Lab of Ornithology, Cornell University, Ithaca, USA
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Ketchaisri O, Siripunkaw C, Plotnik JM. The use of a human's location and social cues by Asian elephants in an object-choice task. Anim Cogn 2019; 22:907-915. [PMID: 31218577 DOI: 10.1007/s10071-019-01283-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 06/10/2019] [Accepted: 06/12/2019] [Indexed: 11/28/2022]
Abstract
Asian elephants have previously demonstrated an ability to follow olfactory cues, but not human-provided social cues like pointing and gazing or orienting to find hidden food (Plotnik et al. in PLoS One 8:e61174, 2013; Anim Behav 88:91-98, 2014). In a study conducted with African elephants, however, elephants were able to follow a combination of these social cues to find food, even when the experimenter's position was counter to the location of the food. The authors of the latter study argued that the differences in the two species' performances might have been due to methodological differences in the study designs (Smet and Byrne in Curr Biol 23(20):2033-2037, 2013). To further investigate the reasons for these potential differences, we partially adapted Smet and Byrne (2013)'s design for a group of Asian elephants in Thailand. In a two-object-choice task in which only one of two buckets was baited with food, we found that, as a group, the elephants did not follow cues provided by an experimenter when she was positioned either equidistant between the buckets or closer to the incorrect bucket when providing the cues. The elephants did, however, follow cues when the experimenter was closer to the correct bucket. In addition, there was individual variability in the elephants' performance within and across experimental conditions. This indicates that in general, for Asian elephants, the pointing and/or gazing cues alone may not be salient enough; local enhancement in the form of the experimenter's position in relation to the food reward may represent a crucial, complementary cue. These results suggest that the variability within and between the species in their performance on these tasks could be due to a number of factors, including methodology, the elephants' experiences with their handlers, ecological differences in how Asian and African elephants use non-visual sensory information to find food in the wild, or some combination of the three.
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Affiliation(s)
- Oraya Ketchaisri
- Conservation Biology Program, Mahidol University, Kanchanaburi Campus, 199 Moo 9, Highway No. 323, Lum Sum, Sai Yok, Kanchanaburi 71150, Thailand
| | - Chomcheun Siripunkaw
- Conservation Biology Program, Mahidol University, Kanchanaburi Campus, 199 Moo 9, Highway No. 323, Lum Sum, Sai Yok, Kanchanaburi 71150, Thailand
| | - Joshua M Plotnik
- Conservation Biology Program, Mahidol University, Kanchanaburi Campus, 199 Moo 9, Highway No. 323, Lum Sum, Sai Yok, Kanchanaburi 71150, Thailand.
- Department of Psychology, Hunter College, City University of New York, 695 Park Avenue, New York, NY, 10065, USA.
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