1
|
Anderson JA, Lin D, Lea AJ, Johnston RA, Voyles T, Akinyi MY, Archie EA, Alberts SC, Tung J. DNA methylation signatures of early-life adversity are exposure-dependent in wild baboons. Proc Natl Acad Sci U S A 2024; 121:e2309469121. [PMID: 38442181 PMCID: PMC10945818 DOI: 10.1073/pnas.2309469121] [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: 06/06/2023] [Accepted: 12/13/2023] [Indexed: 03/07/2024] Open
Abstract
The early-life environment can profoundly shape the trajectory of an animal's life, even years or decades later. One mechanism proposed to contribute to these early-life effects is DNA methylation. However, the frequency and functional importance of DNA methylation in shaping early-life effects on adult outcomes is poorly understood, especially in natural populations. Here, we integrate prospectively collected data on fitness-associated variation in the early environment with DNA methylation estimates at 477,270 CpG sites in 256 wild baboons. We find highly heterogeneous relationships between the early-life environment and DNA methylation in adulthood: aspects of the environment linked to resource limitation (e.g., low-quality habitat, early-life drought) are associated with many more CpG sites than other types of environmental stressors (e.g., low maternal social status). Sites associated with early resource limitation are enriched in gene bodies and putative enhancers, suggesting they are functionally relevant. Indeed, by deploying a baboon-specific, massively parallel reporter assay, we show that a subset of windows containing these sites are capable of regulatory activity, and that, for 88% of early drought-associated sites in these regulatory windows, enhancer activity is DNA methylation-dependent. Together, our results support the idea that DNA methylation patterns contain a persistent signature of the early-life environment. However, they also indicate that not all environmental exposures leave an equivalent mark and suggest that socioenvironmental variation at the time of sampling is more likely to be functionally important. Thus, multiple mechanisms must converge to explain early-life effects on fitness-related traits.
Collapse
Affiliation(s)
- Jordan A. Anderson
- Department of Evolutionary Anthropology, Duke University, Durham, NC27708
| | - Dana Lin
- Department of Evolutionary Anthropology, Duke University, Durham, NC27708
| | - Amanda J. Lea
- Canadian Institute for Advanced Research, Child & Brain Development Program, Toronto, ONM5G 1M1, Canada
- Department of Biological Sciences, Vanderbilt University, Nashville, TN37235
| | | | - Tawni Voyles
- Department of Evolutionary Anthropology, Duke University, Durham, NC27708
| | - Mercy Y. Akinyi
- Institute of Primate Research, National Museums of Kenya, Nairobi00502, Kenya
| | - Elizabeth A. Archie
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN46556
| | - Susan C. Alberts
- Department of Evolutionary Anthropology, Duke University, Durham, NC27708
- Department of Biology, Duke University, Durham, NC27708
- Duke Population Research Institute, Duke University, Durham, NC27708
| | - Jenny Tung
- Department of Evolutionary Anthropology, Duke University, Durham, NC27708
- Canadian Institute for Advanced Research, Child & Brain Development Program, Toronto, ONM5G 1M1, Canada
- Department of Biology, Duke University, Durham, NC27708
- Duke Population Research Institute, Duke University, Durham, NC27708
- Department of Primate Behavior and Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig04103, Germany
| |
Collapse
|
2
|
Age and Social History Impact Social Interactions between Bull Asian Elephants (Elephas maximus) at Denver Zoo. JOURNAL OF ZOOLOGICAL AND BOTANICAL GARDENS 2023. [DOI: 10.3390/jzbg4010018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/06/2023] Open
Abstract
Wild bull Asian elephants spend time in all-male groups. Therefore, managers of ex situ populations increasingly house bulls together. We examined the social interactions of five bull Asian elephants at Denver Zoo, using instantaneous sampling to compare social interactions across adolescent and mature bulls, and bulls with a social history prior to the integration of this group compared to bulls with no social history. Both age and social history significantly affected bull behavior. Adolescent bulls exhibited more affiliative and submissive behaviors when housed with mixed-age and mature social partners compared to with only adolescents, and less non-contact agonistic behavior and less time in proximity to a conspecific with mixed-age groups compared to with only other adolescents. Mature bulls exhibited more affiliative behavior when they were with only adolescent bulls compared to only mature bulls, and more time in proximity to a conspecific and increased contact agonistic behavior with at least one adolescent compared to only mature bulls. Bulls in new social groups engaged in more affiliative, agonistic, and submissive behaviors, and spent less time in proximity, than when they were in previously established social combinations. As more institutions house bulls socially, our results provide insights into factors that may affect bull social interactions.
Collapse
|
3
|
Elephant Scar Prevalence in the Kasigau Wildlife Corridor, Kenya: Echoes of Human-Elephant Conflict. Animals (Basel) 2023; 13:ani13040605. [PMID: 36830392 PMCID: PMC9951691 DOI: 10.3390/ani13040605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Revised: 02/03/2023] [Accepted: 02/07/2023] [Indexed: 02/11/2023] Open
Abstract
Human-elephant conflict (HEC) compromises crop security and threatens elephant conservation. Most commonly, HEC manifests as crop-foraging as elephants modify natural foraging strategies to incorporate crops. Farmers may retaliate by frightening or harming elephants, leaving scars from inflicted wounds. We assessed the prevalence and distribution of scars on the bodies of African savanna elephants (Loxodonta africana) observed in the Kasigau Wildlife Corridor (KWC), part of the Greater Tsavo Ecosystem of Kenya, where conflict is prevalent. We surmised that scars on the body are largely a result of HEC as opposed to scars on the rump or head, which we attributed primarily to elephant-elephant conflict. We hypothesized that: (1) male elephants would have more scars than females; (2) older males would be more likely to have scars than younger males; and (3) most scars would be located on the bodies of elephants. We assessed scars from a photographic catalogue of elephants from the KWC. In line with our hypotheses, male elephants were more likely to have scars than females (32% of males compared to 6% of females); older males had significantly more scars than younger males (61% compared to 24%); and the majority of scars (89%) were located on the body. Scar presence may be useful as an animal-centered indicator to estimate the prevalence and demographic patterns of HEC.
Collapse
|
4
|
Smit JB, Searle CE, Buchanan‐Smith HM, Strampelli P, Mkuburo L, Kakengi VA, Kohi EM, Dickman AJ, Lee PC. Anthropogenic risk increases night‐time activities and associations in African elephants (
Loxodonta africana
) in the
Ruaha‐Rungwa
ecosystem, Tanzania. Afr J Ecol 2022. [DOI: 10.1111/aje.13083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Josephine B. Smit
- Psychology, Faculty of Natural Sciences University of Stirling Stirling UK
- Southern Tanzania Elephant Program Iringa Tanzania
| | - Charlotte E. Searle
- Wildlife Conservation Research Unit, Department of Zoology The Recanati‐Kaplan Centre Tubney UK
- Lion Landscapes Iringa Tanzania
| | | | - Paolo Strampelli
- Wildlife Conservation Research Unit, Department of Zoology The Recanati‐Kaplan Centre Tubney UK
- Lion Landscapes Iringa Tanzania
| | - Lameck Mkuburo
- Southern Tanzania Elephant Program Iringa Tanzania
- Tanzanian Elephant Foundation Moshi Tanzania
| | | | | | - Amy J. Dickman
- Wildlife Conservation Research Unit, Department of Zoology The Recanati‐Kaplan Centre Tubney UK
- Lion Landscapes Iringa Tanzania
| | - Phyllis C. Lee
- Psychology, Faculty of Natural Sciences University of Stirling Stirling UK
| |
Collapse
|
5
|
Social Behavior and Group Formation in Male Asian Elephants (Elephas maximus): The Effects of Age and Musth in Wild and Zoo-Housed Animals. Animals (Basel) 2022; 12:ani12091215. [PMID: 35565641 PMCID: PMC9100748 DOI: 10.3390/ani12091215] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 05/03/2022] [Accepted: 05/06/2022] [Indexed: 12/10/2022] Open
Abstract
Simple Summary The conservation of wild and zoo-housed Asian elephants partly depends on developing our understanding of male elephant social behavior. Once thought to be solitary, we now know that male elephants can display rich social exchanges with both males and females. However, these interactions are expected to change with age and around the sexually active state of “musth.” We used behavioral data from wild and zoo-housed elephant populations to investigate how age, musth, and environmental factors influence how male elephants socialize and associate with group members. In Sri Lanka, only male elephants of older age (>20 years) exhibited signs of musth, but even some of the youngest zoo-housed elephants underwent musth (as young as 11 years). Additionally, we found that age and musth status predicted whether a wild male elephant associated with females, other males or was alone, as well as the number of conspecifics (males and females) in the same group with which a male was observed. Finally, rates of aggression, prosocial behavior (affiliative behaviors that promote positive social bonds between elephants), and submissive behavior exhibited by wild and zoo-housed male elephants were associated with age, musth status, the number of elephants presented, and group type (all-male or mixed sex). These results provide motivation for future studies of social behavior in male Asian elephants, as they will contribute to the reproduction and conservation of this endangered species. Abstract Asian elephants are endangered, and the long-term viability of the species depends on integrative approaches to address the sustainability of in-situ and ex-situ populations. Growing evidence shows that male elephants exhibit extensive and flexible social behavior that rivals the complexity of that of females. Male elephant sociality is expected to change dramatically around the unique sexual state of musth. However, data related to male Asian elephant sociality is lacking. Here, we conducted complementary observations in Wasgamuwa National Park, Sri Lanka, and North American zoos of male Asian elephant social behavior. Age and musth status, along with other factors, were associated with variation in social behavior and group formation of males. In wild male elephants, both musth status and age impacted elephant associations within all-male and mixed-sex groups: non-musth elephants were generally sighted less often in mixed-sex groups as they aged, while the inverse occurred with musth elephants. Musth status interacted with age to predict the number of conspecifics with which a wild male elephant associated: younger males were observed with more females during non-musth (but the opposite was true during musth), and male elephants between 20 and 30 years were observed with the highest number of male conspecifics except during musth. Finally, we found variation in aggression, prosocial behavior, and submissive behavior was influenced by intrinsic (age and musth status) and extrinsic factors (group size and type) in similar ways in both populations; prosocial behavior was most common and was influenced by the number of conspecifics present (both populations), and age, group type, and musth status (zoo population), while aggression was rare, especially among older elephants. We suggest that longitudinal studies of this threatened species will be particularly helpful to promote the reproduction and conservation of Asian elephants in in-situ and ex-situ environments.
Collapse
|
6
|
Lee PC, Moss CJ, Njiraini N, Poole JH, Sayialel K, Fishlock VL. Cohort consequences of drought and family disruption for male and female African elephants. Behav Ecol 2021. [DOI: 10.1093/beheco/arab148] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Cohort effects, reflecting early adversity or advantage, have persisting consequences for growth, reproductive onset, longevity, and lifetime reproductive success. In species with prolonged life histories, cohort effects may establish variation in age-sex structures, while social structure may buffer individuals against early adversity. Using periods of significant ecological adversity, we examined cohort effects for male and female elephants (Loxodonta africana) over almost 50 years in Amboseli, Kenya. Mortality spiked during severe droughts with highest mortality among calves under 2 years and females over 40 years. Deaths of oldest females resulted in social disruption via matriarch turnover, with potential impacts on resource acquisition for survivors. We predicted that survivors of high mortality and social challenges would have altered life-history trajectories, with later age at first reproduction and reduced age-specific fertility for females and slow transitions to independence and late-onset of potential mating or musth among males. Contrary to expectations, there were no persisting early drought effects on female age at first conception while matriarch loss around puberty accelerated reproductive onset. Experience of an early life drought did not influence age-specific reproductive rates once females commenced reproduction. Males who survived an early drought exhibited complex consequences: male age at family independence was later with larger peer cohort size, but earlier with drought in year of independence (13.9 vs 14.6 years). Early drought had no effect on age at first musth, but male reproductive onset was weakly associated with the number of peers (negative) and age at independence (positive).
Collapse
Affiliation(s)
- Phyllis C Lee
- Amboseli Trust for Elephants, Langata, Nairobi, Kenya
- Behaviour & Evolution Research Group, Psychology, Faculty of Natural Sciences, University of Stirling, Stirling, UK
| | | | | | - Joyce H Poole
- ElephantVoices, Buskhellinga 3, 3236 Sandefjord, Norway
| | | | - Vicki L Fishlock
- Amboseli Trust for Elephants, Langata, Nairobi, Kenya
- Centre for Ecology and Conservation, College of Life & Environmental Sciences, University of Exeter, UK
| |
Collapse
|
7
|
Allen CRB, Croft DP, Brent LJN. Reduced older male presence linked to increased rates of aggression to non-conspecific targets in male elephants. Proc Biol Sci 2021; 288:20211374. [PMID: 34933598 PMCID: PMC8692974 DOI: 10.1098/rspb.2021.1374] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Males in many large mammal species spend a considerable portion of their lives in all-male groups segregated from females. In long-lived species, these all-male groups may contain individuals of vastly different ages, providing the possibility that behaviours such as aggression vary with the age demographic of the social environment, as well as an individual's own age. Here, we explore social factors affecting aggression and fear behaviours in non-musth male African elephants (Loxodonta africana) aggregating in an all-male area. Adolescent males had greater probabilities of directing aggressive and fearful behaviours to non-elephant targets when alone compared to when with other males. All males, regardless of age, were less aggressive towards non-elephant targets (e.g. vehicles and non-elephant animals) when larger numbers of males from the oldest age cohort were present. The presence of older males did not influence the probability that other males were aggressive to conspecifics or expressed fearful behaviours towards non-elephant targets. Older bulls may police aggression directed towards non-elephant targets or may lower elephants' perception of their current threat level. Our results suggest male elephants may pose an enhanced threat to humans and livestock when adolescents are socially isolated, and when fewer older bulls are nearby.
Collapse
Affiliation(s)
- Connie R. B. Allen
- Centre for Research in Animal Behaviour, College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QG, UK,Elephants for Africa, 5 Balfour Road, London N5 2HB, UK,School of Biological Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Darren P. Croft
- Centre for Research in Animal Behaviour, College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QG, UK
| | - Lauren J. N. Brent
- Centre for Research in Animal Behaviour, College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QG, UK
| |
Collapse
|
8
|
du Plessis K, Ganswindt SB, Bertschinger H, Crossey B, Henley MD, Ramahlo M, Ganswindt A. Social and Seasonal Factors Contribute to Shifts in Male African Elephant ( Loxodonta africana) Foraging and Activity Patterns in Kruger National Park, South Africa. Animals (Basel) 2021; 11:ani11113070. [PMID: 34827802 PMCID: PMC8614333 DOI: 10.3390/ani11113070] [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: 08/26/2021] [Revised: 10/16/2021] [Accepted: 10/18/2021] [Indexed: 11/16/2022] Open
Abstract
African savannah elephants (Loxodonta africana) are well-known as ecosystem engineers with the ability to modify vegetation structure. The present study aimed to examine how male elephant foraging behaviour is affected across (a) season (wet versus dry); (b) time of day (before or after noon); (c) presence or absence of other elephants; and (d) reproductive state (musth versus no musth). Six radio-collared adult elephant bulls were observed twice per week from June 2007-June 2008 in Kruger National Park (KNP), South Africa. Using generalized linear mixed effect modeling, results indicate that elephant bulls graze more during the wet season and browse more during the dry season. To potentially offset the costs associated with thermoregulation during the heat of the day, KNP elephants spent more time foraging during the morning, and more time resting during the afternoon. Male elephants also foraged significantly less when they were associated with females compared to when they were alone or with other males. This is likely due to male-female associations formed mainly for reproductive purposes, thus impeding on male foraging behaviours. In contrast, the condition of musth, defined by the presence of related physical signs, had no significant effect on foraging behaviour.
Collapse
Affiliation(s)
- Kara du Plessis
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa; (S.B.G.); (B.C.); (M.R.); (A.G.)
- Correspondence:
| | - Stefanie Birgit Ganswindt
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa; (S.B.G.); (B.C.); (M.R.); (A.G.)
| | - Henk Bertschinger
- Veterinary Population Management Laboratory, Section of Reproduction, Department of Production Animal Studies, University of Pretoria, Private Bag X04, Onderstepoort 0110, South Africa;
| | - Bruce Crossey
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa; (S.B.G.); (B.C.); (M.R.); (A.G.)
| | - Michelle Deborah Henley
- Applied Behavioural Ecology and Ecosystem Research Unit, School of Environmental Sciences, University of South Africa, Private Bag X5, Florida 1710, South Africa;
- Elephants Alive, P.O. Box 960, Hoedspruit 1380, South Africa
| | - Mmatsawela Ramahlo
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa; (S.B.G.); (B.C.); (M.R.); (A.G.)
| | - André Ganswindt
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa; (S.B.G.); (B.C.); (M.R.); (A.G.)
| |
Collapse
|
9
|
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.
Collapse
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;
| |
Collapse
|
10
|
LaDue CA, Schulte BA, Kiso WK, Freeman EW. Musth and sexual selection in elephants: a review of signalling properties and potential fitness consequences. BEHAVIOUR 2021. [DOI: 10.1163/1568539x-bja10120] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Abstract
Sexual selection mediated by multimodal signals is common among polygynous species, including seasonally breeding mammals. Indirect benefit models provide plausible explanations for how and why mate selection can occur in the absence of direct benefits. Musth — an asynchronous reproductive state in male elephants — facilitates both inter- and intrasexual selection via indirect benefits, and it is further communicated through a multimodal signal. In this review, we synthesise existing evidence that supports the hypothesis that musth is a multimodal signal subject to sexual selection and that male elephants increase their direct fitness by propagating this signal while females accrue indirect benefits. Musth is characterised by a suite of physiological and behavioural changes, serving to facilitate copulation between the sexes, and via multisensory modalities musth conveys honest information about the condition of a male. Female elephants mate preferentially with musth males, increasing their own fitness in the absence of direct benefits. In addition, musth resolves dynamic dominance hierarchies among male elephants and often eliminates the need for costly physical combat. Future work in this field should investigate potential postcopulatory selection mechanisms in elephants, including sperm competition and cryptic female choice. These topics join other fundamental questions related to sexual selection, signalling, and indirect benefits that are still unanswered in elephants.
Collapse
Affiliation(s)
- Chase A. LaDue
- Department of Environmental Science and Policy, George Mason University, Fairfax, VA, USA
| | - Bruce A. Schulte
- Department of Biology, Western Kentucky University, Bowling Green, KY, USA
| | | | | |
Collapse
|
11
|
|
12
|
LaDue CA, Vandercone RPG, Kiso WK, Freeman EW. Scars of human–elephant conflict: patterns inferred from field observations of Asian elephants in Sri Lanka. WILDLIFE RESEARCH 2021. [DOI: 10.1071/wr20175] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Abstract
ContextHuman–elephant conflict (HEC) is a major threat to Asian elephants as humans and elephants are forced to share common resources. In Sri Lanka, human-dominated landscapes adjacent to protected areas promote high rates of HEC, especially in the form of crop-foraging by elephants. Crop-foraging can be dangerous to both elephants and humans involved in the conflict. Gunfire is a common way for human communities to deter crop-foraging elephants, and gunshot wounds are commonly described in this elephant population on necropsy.
AimsWe sought to quantify and describe unique scar patterns among Asian elephants in a protected area, Wasgamuwa National Park, attributed to HEC.
MethodsWe identified 38 adult female and 64 adult male elephants and recorded the age class and body condition of each with established standards. Using photographs, we counted the number, position, and relative size of all scars on each animal.
Key resultsMale elephants had significantly more scars than did females, and for males, the number of scars increased progressively with age. Additionally, male elephants with higher body conditions had more scars. Finally, males tended to have more scars towards the head, especially at older ages.
ConclusionsDifferences in total scar counts between the sexes in this population imply that male elephants in this area more frequently engage in HEC than do females, following observations previously described in the literature. Furthermore, the fact that male elephants acquired progressively more scars as they aged, and that fatter elephants had more scars, indicates that previous exposure to HEC may not have been a deterrent for future events among these males, and potentially, crops served as valuable food sources for these animals. Finally, the changing body locations of these scars with age in males possibly shows plastic behavioural responses during crop-foraging or lower tolerance by farmers towards habitual crop foragers.
ImplicationsThese results emphasise the need for animal-based approaches to HEC mitigation. Similarly, conservation managers in Sri Lanka and other elephant range countries should investigate similar methods that estimate patterns of HEC to develop effective management strategies directly targeting animals most likely to engage in conflict.
Collapse
|
13
|
Kioko J, Horton A, Libre M, Vickers J, Dressel E, Kasey H, Ndegeya PM, Gadiye D, Kissui B, Kiffner C. Distribution and abundance of African elephants in Ngorongoro Crater, northern Tanzania. AFRICAN ZOOLOGY 2020. [DOI: 10.1080/15627020.2020.1813625] [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)
- John Kioko
- School for Field Studies, Karatu, Tanzania
| | - Alanna Horton
- Department of Biology, Davidson College, Davidson, North Carolina, United States
| | - Margo Libre
- Department of Biology, Muhlenberg College, Allentown, United States
| | | | - Emma Dressel
- Department of Biology, University of Richmond, Richmond, Virginia, United States
| | - Heather Kasey
- Prescott College, Abington, Pennsylvania, United States
| | | | - Donatus Gadiye
- Ngorongoro Conservation Area Authority, Karatu, Tanzania
| | | | | |
Collapse
|
14
|
Weckerly FW. Frequency and Density Associated Grouping Patterns of Male Roosevelt Elk. Front Ecol Evol 2020. [DOI: 10.3389/fevo.2020.00204] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
15
|
|
16
|
Srinivasaiah N, Kumar V, Vaidyanathan S, Sukumar R, Sinha A. All-Male Groups in Asian Elephants: A Novel, Adaptive Social Strategy in Increasingly Anthropogenic Landscapes of Southern India. Sci Rep 2019; 9:8678. [PMID: 31273235 PMCID: PMC6609637 DOI: 10.1038/s41598-019-45130-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Accepted: 05/29/2019] [Indexed: 01/11/2023] Open
Abstract
Male Asian elephants are known to adopt a high-risk high-gain foraging strategy by venturing into agricultural areas and feeding on nutritious crops in order to improve their reproductive fitness. We hypothesised that the high risks to survival posed by increasingly urbanising and often unpredictable production landscapes may necessitate the emergence of behavioural strategies that allow male elephants to persist in such landscapes. Using 1445 photographic records of 248 uniquely identified male Asian elephants over a 23-month period, we show that male Asian elephants display striking emergent behaviour, particularly the formation of stable, long-term all-male groups, typically in non-forested or human-modified and highly fragmented areas. They remained solitary or associated in mixed-sex groups, however, within forested habitats. These novel, large all-male associations, may constitute a unique life history strategy for male elephants in the high-risk but resource-rich production landscapes of southern India. This may be especially true for the adolescent males, which seemed to effectively improve their body condition by increasingly exploiting anthropogenic resources when in all-male groups. This observation further supports our hypothesis that such emergent behaviours are likely to constitute an adaptive strategy for male Asian elephants that may be forced to increasingly confront anthropogenically intrusive environments.
Collapse
Affiliation(s)
- Nishant Srinivasaiah
- National Institute of Advanced Studies, Animal Behaviour and Cognition Programme, Bengaluru, 560012, India.
| | - Vinod Kumar
- Foundation for Ecological Research, Advocacy and Learning, Pondicherry, 605101, India
| | - Srinivas Vaidyanathan
- Foundation for Ecological Research, Advocacy and Learning, Pondicherry, 605101, India
| | - Raman Sukumar
- Indian Institute of Science, Centre for Ecological Sciences, Bengaluru, 560012, India
| | - Anindya Sinha
- National Institute of Advanced Studies, Animal Behaviour and Cognition Programme, Bengaluru, 560012, India.,Indian Institute of Science Education and Research Kolkata, Mohanpur, 741246, India
| |
Collapse
|
17
|
Boult VL, Sibly RM, Quaife T, Fishlock V, Moss C, Lee PC. Modelling large herbivore movement decisions: Beyond food availability as a predictor of ranging patterns. Afr J Ecol 2018. [DOI: 10.1111/aje.12553] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
| | | | - Tristan Quaife
- Department of Meteorology University of Reading Reading UK
| | - Vicki Fishlock
- Amboseli Trust for Elephants University of Stirling Stirling UK
- Psychology, Faculty of Natural Sciences University of Stirling Stirling UK
| | - Cynthia Moss
- Amboseli Trust for Elephants University of Stirling Stirling UK
| | - Phyllis C. Lee
- Amboseli Trust for Elephants University of Stirling Stirling UK
- Psychology, Faculty of Natural Sciences University of Stirling Stirling UK
| |
Collapse
|
18
|
Gara TW, Wang T, Skidmore AK, Zengeya FM, Ngene SM, Murwira A, Ndaimani H. Understanding the effect of landscape fragmentation and vegetation productivity on elephant habitat utilization in Amboseli ecosystem, Kenya. Afr J Ecol 2016. [DOI: 10.1111/aje.12346] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Tawanda W. Gara
- Faculty of Geo-Information Science and Earth Observation (ITC); University of Twente; Hengelosestraat 99 PO Box 6 7500 AA Enschede The Netherlands
- University of Zimbabwe; Department of Geography and Environmental Science; P.O. Box, MP167 Mount Pleasant Harare Zimbabwe
| | - Tiejun Wang
- Faculty of Geo-Information Science and Earth Observation (ITC); University of Twente; Hengelosestraat 99 PO Box 6 7500 AA Enschede The Netherlands
| | - Andrew K. Skidmore
- Faculty of Geo-Information Science and Earth Observation (ITC); University of Twente; Hengelosestraat 99 PO Box 6 7500 AA Enschede The Netherlands
| | - Fadzai M. Zengeya
- University of Zimbabwe; Department of Geography and Environmental Science; P.O. Box, MP167 Mount Pleasant Harare Zimbabwe
| | | | - Amon Murwira
- University of Zimbabwe; Department of Geography and Environmental Science; P.O. Box, MP167 Mount Pleasant Harare Zimbabwe
| | - Henry Ndaimani
- University of Zimbabwe; Department of Geography and Environmental Science; P.O. Box, MP167 Mount Pleasant Harare Zimbabwe
| |
Collapse
|