1
|
Pokharel SS, Brown JL. Physiological plasticity in elephants: highly dynamic glucocorticoids in African and Asian elephants. CONSERVATION PHYSIOLOGY 2023; 11:coad088. [PMCID: PMC10673820 DOI: 10.1093/conphys/coad088] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 10/04/2023] [Accepted: 11/01/2023] [Indexed: 09/27/2024]
Abstract
Slowly reproducing and long-lived terrestrial mammals are often more at risk from challenges that influence fitness and survival. It is, therefore, important to understand how animals cope with such challenges and how coping mechanisms translate over generations and affect phenotypic plasticity. Rapidly escalating anthropogenic challenges may further diminish an animal’s ability to reinstate homeostasis. Research to advance insights on elephant stress physiology has predominantly focused on relative or comparative analyses of a major stress response marker, glucocorticoids (GCs), across different ecological, anthropogenic, and reproductive contexts. This paper presents an extensive review of published findings on Asian and African elephants from 1980 to 2023 (May) and reveals that stress responses, as measured by alterations in GCs in different sample matrices, often are highly dynamic and vary within and across individuals exposed to similar stimuli, and not always in a predictable fashion. Such dynamicity in physiological reactivity may be mediated by individual differences in personality traits or coping styles, ecological conditions, and technical factors that often are not considered in study designs. We describe probable causations under the ‘Physiological Dynamicity Model’, which considers context–experience–individuality effects. Highly variable adrenal responses may affect physiological plasticity with potential fitness and survival consequences. This review also addresses the significance of cautious interpretations of GCs data in the context of normal adaptive stress versus distress. We emphasize the need for long-term assessments of GCs that incorporate multiple markers of ‘stress’ and ‘well-being’ to decipher the probable fitness consequences of highly dynamic physiological adrenal responses in elephants. Ultimately, we propose that assessing GC responses to current and future challenges is one of the most valuable and informative conservation tools we have for guiding conservation strategies.
Collapse
Affiliation(s)
- Sanjeeta Sharma Pokharel
- Center for Species Survival, Smithsonian National Zoo Conservation Biology Institute, 1500 Remount Road, Front Royal, VA 22630, USA
| | - Janine L Brown
- Center for Species Survival, Smithsonian National Zoo Conservation Biology Institute, 1500 Remount Road, Front Royal, VA 22630, USA
| |
Collapse
|
2
|
Woodruff MC, Atencia R, Cox D, Woodruff GT, Wheaton CJ, Lavin SR, Setchell JM. Successful acclimatization of mandrills ( Mandrillus sphinx) translocated to Conkouati-Douli National Park, Republic of Congo, as measured by fecal glucocorticoid metabolites. CONSERVATION PHYSIOLOGY 2023; 11:coad025. [PMID: 37179706 PMCID: PMC10170324 DOI: 10.1093/conphys/coad025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Revised: 03/11/2023] [Accepted: 04/14/2023] [Indexed: 05/15/2023]
Abstract
Translocation and reintroduction are common tools in conservation management and can be very successful. However, translocation can be stressful for the animals involved, and stress is implicated as a major cause of failure in release programs. Conservation managers should therefore seek to understand how the stages of translocation impact stress physiology in the animals involved. We quantified fecal glucocorticoid metabolites (fGCMs) as a noninvasive measure of response to potential stressors during a translocation of 15 mandrills (Mandrillus sphinx) into Conkouati-Douli National Park, Republic of Congo. The mandrills were initially housed in a sanctuary, transferred to a pre-release enclosure in the National Park and then released into the forest. We collected repeated fecal samples (n = 1101) from known individuals and quantified fGCMs using a previously validated enzyme immunoassay. Transfer from the sanctuary to the pre-release enclosure correlated with a significant 1.93-fold increase in fGCMs, suggesting that transfer was a stressor for the mandrills. fGCM values decreased over time in the pre-release enclosure, suggesting that the mandrills recovered from the transfer and acclimatized to the enclosure. Release to the forest was not linked to a significant increase in fGCMs over the final values in the enclosure. Following release, fGCMs continued to decrease, fell below sanctuary values after just over a month and were about half the sanctuary values after 1 year. Overall, our results suggest that the translocation, although initially presenting a physiological challenge to the animals, was not detrimental to the well-being of the animals over the timescale of the study and, in fact, may have been beneficial. Our findings show the value of non-invasive physiology in monitoring, evaluating and designing wildlife translocations and, ultimately, contributing to their success.
Collapse
Affiliation(s)
- Miles C Woodruff
- Department of Anthropology, Durham University, South Road, Durham, DH1 3LE, UK
| | - Rebeca Atencia
- The Jane Goodall Institute, 1120 20th St NW, Washington, DC 20036, USA
| | - Debby Cox
- The Jane Goodall Institute, 1120 20th St NW, Washington, DC 20036, USA
| | - Glenn T Woodruff
- The Jane Goodall Institute, 1120 20th St NW, Washington, DC 20036, USA
| | | | - Shana R Lavin
- Disney’s Animals, Science and Environment, Bay Lake, FL, 32830, USA
| | - Joanna M Setchell
- Department of Anthropology, Durham University, South Road, Durham, DH1 3LE, UK
| |
Collapse
|
3
|
Pero EM, Chitwood MC, Hildreth AM, Keller BJ, Millspaugh RJ, Sumners JA, Hansen LP, Isabelle JL, Breuner CW, Millspaugh JJ. Physiological acclimation of elk during population restoration in the Missouri Ozarks, USA. CONSERVATION PHYSIOLOGY 2022; 10:coac009. [PMID: 35492406 PMCID: PMC9040282 DOI: 10.1093/conphys/coac009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 01/25/2022] [Accepted: 03/01/2022] [Indexed: 06/14/2023]
Abstract
Conservation translocations-the intentional movement of animals to restore populations-have increased over the past 30 years to halt and reverse species declines and losses. However, there are many challenges translocated animals face that should be considered for restoration programs to be successful. Understanding how long it takes for translocated animals to acclimate to these challenges and their new landscape is a critical component of post-release population management. Physiological measures such as hormone responses are increasingly used to assess animal responses and acclimation to disturbances including translocation. We determined the physiological acclimation period of elk (Cervus canadensis) translocated to the Missouri Ozarks, USA, as part of a restoration effort. From 2011 to 2013, we translocated 108 GPS-radio-collared elk from Kentucky, USA, to Missouri, USA, and collected faecal samples for glucocorticoid metabolite extraction to use as an indicator of physiological acclimation. We modelled the response of population-wide faecal glucocorticoid metabolites (fGCMs) across the initial 9 years of the restoration in response to days following release and additional site-specific covariates. Presence of white-tailed deer (Odocoileus virginianus) hunts and monthly precipitation levels were positively and negatively associated with fGCM levels, respectively. Concurrent with influences from site-specific conditions on the release landscape, fGCM levels declined following release. We identified a breakpoint in fGCM decline at ~42 days following translocation releases suggesting elk acclimated physiologically relatively quickly compared to other species. The fast physiological acclimation by Missouri elk suggests effective use of temporary post-release management efforts. Determining how quickly animals acclimate following translocations allows researchers to tailor post-release management plans to each species' needs, thus maximizing the success of future translocation efforts while minimizing costs.
Collapse
Affiliation(s)
- Ellen M Pero
- Corresponding author: Wildlife Biology Program, University of Montana, 32 Campus Drive, Missoula, MT 59812, USA. Tel: +1 (810) 623-1218.
| | - M Colter Chitwood
- Natural Resource Ecology & Management, Oklahoma State University, 008C Agriculture Hall, Stillwater, OK 74078, USA
| | - Aaron M Hildreth
- Missouri Department of Conservation, 3500 E Gans Rd, Columbia, MO 65201, USA
| | - Barbara J Keller
- Minnesota Department of Natural Resources, 500 Lafayette Rd, St. Paul, MN 55155, USA
| | - Rami J Millspaugh
- School of Natural Resources, University of Missouri, Columbia, MO 65211, USA
| | - Jason A Sumners
- Missouri Department of Conservation, 2901 W Truman Blvd, Jefferson City, MO 65102, USA
| | - Lonnie P Hansen
- Missouri Department of Conservation, 3500 E Gans Rd, Columbia, MO 65201, USA
| | - Jason L Isabelle
- Missouri Department of Conservation, 3500 E Gans Rd, Columbia, MO 65201, USA
| | - Creagh W Breuner
- Division of Biological Sciences, University of Montana, 32 Campus Drive, Missoula, MT 59812, USA
| | - Joshua J Millspaugh
- Wildlife Biology Program, University of Montana, 32 Campus Drive, Missoula, MT 59812, USA
| |
Collapse
|
4
|
Shultz S, Britnell JA, Harvey N. Untapped potential of physiology, behaviour and immune markers to predict range dynamics and marginality. Ecol Evol 2021; 11:16446-16461. [PMID: 34938448 PMCID: PMC8668750 DOI: 10.1002/ece3.8331] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 09/09/2021] [Accepted: 10/14/2021] [Indexed: 11/16/2022] Open
Abstract
Linking environmental conditions to the modulators of individual fitness is necessary to predict long-term population dynamics, viability, and resilience. Functional physiological, behavioral, and reproductive markers can provide this mechanistic insight into how individuals perceive physiological, psychological, chemical, and physical environmental challenges through physiological and behavioral responses that are fitness proxies. We propose a Functional Marginality framework where relative changes in allostatic load, reproductive health, and behavior can be scaled up to evidence and establish causation of macroecological processes such as local extirpation, colonization, population dynamics, and range dynamics. To fully exploit functional traits, we need to move beyond single biomarker studies to develop an integrative approach that models the interactions between extrinsic challenges, physiological, and behavioral pathways and their modulators. In addition to providing mechanistic markers of range dynamics, this approach can also serve as a valuable conservation tool for evaluating individual- and population-level health, predicting responses to future environmental change and measuring the impact of interventions. We highlight specific studies that have used complementary biomarkers to link extrinsic challenges to population performance. These frameworks of integrated biomarkers have untapped potential to identify causes of decline, predict future changes, and mitigate against future biodiversity loss.
Collapse
Affiliation(s)
- Susanne Shultz
- School of Earth and Environmental SciencesUniversity of ManchesterManchesterUK
| | - Jake A. Britnell
- School of Earth and Environmental SciencesUniversity of ManchesterManchesterUK
- Chester ZooUpton‐By‐ChesterUK
| | - Nicholas Harvey
- School of Earth and Environmental SciencesUniversity of ManchesterManchesterUK
- Chester ZooUpton‐By‐ChesterUK
| |
Collapse
|
5
|
Szott ID, Pretorius Y, Ganswindt A, Koyama NF. Physiological stress response of African elephants to wildlife tourism in Madikwe Game Reserve, South Africa. WILDLIFE RESEARCH 2020. [DOI: 10.1071/wr19045] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Abstract
ContextWildlife tourism has been shown to increase stress in a variety of species and can negatively affect survival, reproduction, welfare, and behaviour of individuals. In African elephants, Loxodonta africana, increased physiological stress has been linked to use of refugia, rapid movement through corridors, and heightened aggression towards humans. However, we are unaware of any studies assessing the impact of tourism pressure (tourist numbers) on physiological stress in elephants.
AimsWe used faecal glucocorticoid metabolite (fGCM) concentrations to investigate whether tourist numbers in Madikwe Game Reserve, South Africa, were related to changes in physiological stress in elephants.
MethodsWe repeatedly collected dung samples (n=43) from 13 individually identified elephants over 15 months. Using a generalised linear mixed model and a Kenward–Roger approximation, we assessed the impact of monthly tourist numbers, season, age, and sex on elephant fGCM concentrations.
Key resultsHigh tourist numbers were significantly related to elevated fGCM concentrations. Overall, fGCM concentrations increased by 112% (from 0.26 to 0.55µgg−1 dry weight) in the months with the highest tourist pressure, compared to months with the lowest tourist pressure.
ConclusionsManagers of fenced reserves should consider providing potential alleviation measures for elephants during high tourist pressure, for example, by ensuring that refuge areas are available. This may be of even higher importance if elephant populations have had traumatic experiences with humans in the past, such as poaching or translocation. Such management action will improve elephant welfare and increase tourist safety.
ImplicationsAlthough tourism can generate substantial revenue to support conservation action, careful monitoring of its impact on wildlife is required to manage potential negative effects.
Collapse
|
6
|
Increasing conservation translocation success by building social functionality in released populations. Glob Ecol Conserv 2019. [DOI: 10.1016/j.gecco.2019.e00604] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
|
7
|
Szott ID, Pretorius Y, Koyama NF. Behavioural changes in African elephants in response to wildlife tourism. J Zool (1987) 2019. [DOI: 10.1111/jzo.12661] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- I. D. Szott
- School of Natural Sciences and Psychology Liverpool John Moores University Liverpool UK
| | - Y. Pretorius
- Centre for Wildlife Management University of Pretoria Pretoria South Africa
| | - N. F. Koyama
- School of Natural Sciences and Psychology Liverpool John Moores University Liverpool UK
| |
Collapse
|
8
|
Navarro JL, Lèche A, Della Costa NS, Vera Cortez M, Marin RH, Martella MB. State of the art knowledge in adrenocortical and behavioral responses to environmental challenges in a threatened South American ratite: Implications to in situ and ex-situ conservation. Gen Comp Endocrinol 2019; 273:52-60. [PMID: 29656044 DOI: 10.1016/j.ygcen.2018.04.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 04/04/2018] [Accepted: 04/11/2018] [Indexed: 10/17/2022]
Abstract
The Greater Rhea (Rhea americana) is an endemic ratite to South America, whose wild populations have undergone a remarkable decrease due to habitat degradation and fragmentation by the expansion of the agricultural frontier, poaching and predation by dogs. Anthropogenic perturbations in wild environments, as well as the management in captivity, can generate different stress responses in this species, thus, the monitoring of adrenocortical and behavioral activities are considered primary assessment tools with both conservation and welfare implications. In this review we analyze and integrate the different measurements of glucocorticoids (in plasma, feces, and yolk) carried out in different captive and wild populations, taking into account the diverse predictable and unpredictable conditions to which the Greater Rhea responds in each of those environments. In addition, the translocation of this bird is presented as an application of stress physiology in field ecology for conservation purposes, in which we evaluated how this species responds when it is released into a novel environment. Our results indicate that this ratite has a striking high sensitivity of the hypothalamic-pituitary-adrenal (HPA) axis compared to that of other bird species and shows a wide variety of adrenocortical responses depending on the environment in which it lives. This suggests that its HPA axis has a phenotypic plasticity that enables the rhea to cope with the environmental challenges. In this sense, we propose that one of the routes of this plasticity could be mediated by the maternal transfer of steroid hormones to the egg. Finally, we discuss the importance of integrating the monitoring of the adrenocortical response along with the environmental variables that define the life history of the species, in management and conservation programs ex-situ and in situ.
Collapse
Affiliation(s)
- Joaquín Luis Navarro
- Universidad Nacional de Córdoba, Facultad de Ciencias Exactas, Físicas y Naturales, Centro de Zoología Aplicada, Rondeau 798, CP 5000 Córdoba, Argentina; Universidad Nacional de Córdoba, Facultad de Ciencias Exactas, Físicas y Naturales, Departamento de Diversidad Biológica y Ecología, Cátedra de Problemática Ambiental, Av. Vélez Sarsfield 299, CP 5000 Córdoba, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Diversidad y Ecología Animal (IDEA), Av. Vélez Sarsfield 299, CP 5000 Córdoba, Argentina
| | - Alvina Lèche
- Universidad Nacional de Córdoba, Facultad de Ciencias Exactas, Físicas y Naturales, Centro de Zoología Aplicada, Rondeau 798, CP 5000 Córdoba, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Diversidad y Ecología Animal (IDEA), Av. Vélez Sarsfield 299, CP 5000 Córdoba, Argentina
| | - Natalia S Della Costa
- Universidad Nacional de Córdoba, Facultad de Ciencias Exactas, Físicas y Naturales, Centro de Zoología Aplicada, Rondeau 798, CP 5000 Córdoba, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Diversidad y Ecología Animal (IDEA), Av. Vélez Sarsfield 299, CP 5000 Córdoba, Argentina
| | - Marilina Vera Cortez
- Universidad Nacional de Córdoba, Facultad de Ciencias Exactas, Físicas y Naturales, Centro de Zoología Aplicada, Rondeau 798, CP 5000 Córdoba, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Diversidad y Ecología Animal (IDEA), Av. Vélez Sarsfield 299, CP 5000 Córdoba, Argentina
| | - Raúl H Marin
- Universidad Nacional de Córdoba, Facultad de Ciencias Exactas, Físicas y Naturales, Instituto de Ciencia y Tecnología de los Alimentos (ICTA) y Cátedra de Química Biológica, Av. Vélez Sarsfield 1611, X5000AVP Córdoba, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Investigaciones Biológicas y Tecnológicas (IIBYT), Av. Vélez Sarsfield 1611, CP 5016 Córdoba, Argentina
| | - Mónica B Martella
- Universidad Nacional de Córdoba, Facultad de Ciencias Exactas, Físicas y Naturales, Centro de Zoología Aplicada, Rondeau 798, CP 5000 Córdoba, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Diversidad y Ecología Animal (IDEA), Av. Vélez Sarsfield 299, CP 5000 Córdoba, Argentina.
| |
Collapse
|
9
|
Jachowski DS, Washburn BE, Millspaugh JJ. Revisiting the importance of accounting for seasonal and diel rhythms in fecal stress hormone studies. WILDLIFE SOC B 2015. [DOI: 10.1002/wsb.592] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- David S. Jachowski
- Department of Forestry and Environmental Conservation; Clemson University; 258 Lehotsky Hall Clemson SC 29634 USA
| | - Brian E. Washburn
- United States Department of Agriculture; Wildlife Services, National Wildlife Research Center; 6100 Columbus Avenue Sandusky OH 44870 USA
| | - Joshua J. Millspaugh
- Department of Fisheries and Wildlife Sciences; University of Missouri; 302 Natural Resources Building Columbia MO 65211 USA
| |
Collapse
|
10
|
Anderson LE, Cree A, Towns DR, Nelson NJ. Moving house: long-term dynamics of corticosterone secretion are unaltered in translocated populations of a rare reptile (the tuatara, Sphenodon punctatus). CONSERVATION PHYSIOLOGY 2015; 3:cov014. [PMID: 27293699 PMCID: PMC4778483 DOI: 10.1093/conphys/cov014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Revised: 03/02/2015] [Accepted: 03/04/2015] [Indexed: 05/13/2023]
Abstract
Translocations are an important conservation tool used to restore at-risk species to their historical range. Unavoidable procedures during translocations, such as habitat disturbance, capture, handling, processing, captivity, transport and release to a novel environment, have the potential to be stressful for most species. In this study, we examined acute and chronic stress (through the measurement of the glucocorticoid corticosterone) in a rare reptile (the tuatara, Sphenodon punctatus). We found that: (i) the acute corticosterone response remains elevated during the initial translocation process but is not amplified by cumulative stressors; and (ii) the long-term dynamics of corticosterone secretion are similar in translocated and source populations. Taken together, our results show that translocated tuatara are generally resistant to cumulative acute stressors and show no hormonal sign of chronic stress. Translocation efforts in tuatara afford the potential to reduce extinction risk and restore natural ecosystems.
Collapse
Affiliation(s)
- Lindsay E. Anderson
- Allan Wilson Centre for Molecular Ecology and Evolution, School of Biological Sciences, Victoria University of Wellington, PO Box 600, Wellington 6140, New Zealand
- Corresponding author:Allan Wilson Centre for Molecular Ecology and Evolution, School of Biological Sciences, Victoria University of Wellington, PO Box 600, Wellington 6140, New Zealand. Tel: +1 250 551 2884.
| | - Alison Cree
- Department of Zoology, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - David R. Towns
- Ecosystem Development Team, Science and Technical Group, Department of Conservation, Private Bag 68-908 Newton, Auckland 1145, New Zealand
| | - Nicola J. Nelson
- Allan Wilson Centre for Molecular Ecology and Evolution, School of Biological Sciences, Victoria University of Wellington, PO Box 600, Wellington 6140, New Zealand
| |
Collapse
|
11
|
Jachowski DS, Dobony CA, Coleman LS, Ford WM, Britzke ER, Rodrigue JL. Disease and community structure: white-nose syndrome alters spatial and temporal niche partitioning in sympatric bat species. DIVERS DISTRIB 2014. [DOI: 10.1111/ddi.12192] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Affiliation(s)
- David S. Jachowski
- Department of Fisheries and Wildlife Conservation; Virginia Polytechnic Institute and State University; Blacksburg VA 24061 USA
| | - Chris A. Dobony
- Fort Drum Military Installation; Natural Resources Branch; 85 First Street West IMNE-DRM-PWE Fort Drum NY 13602 USA
| | - Laci S. Coleman
- Department of Fisheries and Wildlife Conservation; Virginia Polytechnic Institute and State University; Blacksburg VA 24061 USA
| | - William M. Ford
- U.S. Geological Survey; Virginia Cooperative Fish and Wildlife Research Unit; Virginia Polytechnic Institute and State University; Blacksburg VA 24061 USA
| | - Eric R. Britzke
- U.S. Army Research and Development Center; Environmental Laboratory; Vicksburg MS 39180 USA
| | - Jane L. Rodrigue
- U.S. Forest Service; Northern Research Station Princeton WV 24740 USA
| |
Collapse
|
12
|
Jachowski DS, Montgomery RA, Slotow R, Millspaugh JJ. Unravelling complex associations between physiological state and movement of African elephants. Funct Ecol 2013. [DOI: 10.1111/1365-2435.12118] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | | | - Rob Slotow
- Amarula Elephant Research Programme; School of Life Sciences; University of KwaZulu-Natal; Westville Campus; Durban; South Africa
| | - Joshua J. Millspaugh
- Department of Fisheries and Wildlife Sciences; University of Missouri; Columbia; Missouri; 65201; USA
| |
Collapse
|