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Hariohay KM, Hunninck L, Ranke PS, Fyumagwa RD, Palme R, Røskaft E. Between hunter and climate: the effects of hunting and environmental change on fecal glucocorticoid metabolite levels in two sympatric ungulate species in the Ruaha-Rungwa ecosystem, Tanzania. CONSERVATION PHYSIOLOGY 2023; 11:coad002. [PMID: 38026801 PMCID: PMC10660377 DOI: 10.1093/conphys/coad002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 11/22/2022] [Accepted: 01/31/2023] [Indexed: 12/01/2023]
Abstract
Understanding the drivers of animal population decline is a key focus of conservation biologists. Anthropogenic activities such as hunting have long been established as potentially detrimental to a population's persistence. However, environmental perturbations such as increased temperature variability, exacerbated by climate change, can also have important effects on animal populations. Animals can respond to these challenges by adjusting both their behavior and physiology. We measured fecal glucocorticoid metabolites (FGMs) of common impala (Aepyceros melampus) and greater kudu (Tragelaphus strepsiceros), both currently in stable populations, to examine effects of hunting, forage availability, daily variability in temperature and group size on their physiological stress response. The study was conducted across two adjacent protected areas, (i) one non-hunted area (Ruaha National Park; RNP) and (ii) one area used for trophy hunting (Rungwa Game Reserve; RGR). Both impala and kudu had significantly higher FGM levels in the area that allows hunting, while FGM levels decreased with increasing forage availability and increasing daily temperature. Moreover, impala (but not kudu) had lower FGM levels with larger group sizes. Our results indicate that the management regime can significantly alter the physiological state of wild ungulate populations. We also highlight the importance of considering the combined effects of anthropogenic, environmental and social contexts when studying the stress response of wild populations. Our results emphasize the value of protected areas and continued monitoring of hunting quota in order to maintain ungulate populations that are less vulnerable to population declines.
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Affiliation(s)
- Kwaslema Malle Hariohay
- Department of Wildlife Management, College of African Wildlife Management, Mweka, P. O. Box 3031, Moshi, Tanzania
- Department of Biology, Norwegian University of Science and Technology, Realfagbygget, NO-7491, Trondheim, Norway
| | - Louis Hunninck
- Department of Biology, Norwegian University of Science and Technology, Realfagbygget, NO-7491, Trondheim, Norway
- Department of Natural Resources and Environmental Sciences, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
| | - Peter S Ranke
- Department of Biology, Norwegian University of Science and Technology, Realfagbygget, NO-7491, Trondheim, Norway
- Center for Biodiversity Dynamics (CBD), Department of Biology, Norwegian University of Science and Technology, Realfagbygget, NO-7491, Trondheim, Norway
| | - Robert D Fyumagwa
- Department of Wildlife Management, Tanzania Wildlife Research Institute (TAWIRI), P.O. Box 661, Arusha
| | - Rupert Palme
- Department of Biomedical Sciences, University of Veterinary Medicine, Vienna
| | - Eivin Røskaft
- Department of Biology, Norwegian University of Science and Technology, Realfagbygget, NO-7491, Trondheim, Norway
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Thant ZM, May R, Røskaft E. Human–elephant coexistence challenges in Myanmar: An analysis of fatal elephant attacks on humans and elephant mortality. J Nat Conserv 2022. [DOI: 10.1016/j.jnc.2022.126260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
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Tavolaro FM, Woodgate Z, Brown C, Redpath SM, O'Riain MJ. Multispecies study of patterns and drivers of wildlife impacts on human livelihoods in communal conservancies. CONSERVATION SCIENCE AND PRACTICE 2022. [DOI: 10.1111/csp2.12773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Affiliation(s)
- Francesca Marina Tavolaro
- Institute for Communities and Wildlife in Africa (iCWild) University of Cape Town Cape Town South Africa
- Namibian Chamber of Environment (NCE) Windhoek Namibia
| | - Zoe Woodgate
- Institute for Communities and Wildlife in Africa (iCWild) University of Cape Town Cape Town South Africa
| | - Chris Brown
- Namibian Chamber of Environment (NCE) Windhoek Namibia
| | - Steve M. Redpath
- Institute for Communities and Wildlife in Africa (iCWild) University of Cape Town Cape Town South Africa
| | - Mannus Justin O'Riain
- Institute for Communities and Wildlife in Africa (iCWild) University of Cape Town Cape Town South Africa
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Benitez L, Kilian JW, Wittemyer G, Hughey LF, Fleming CH, Leimgruber P, du Preez P, Stabach JA. Precipitation, vegetation productivity, and human impacts control home range size of elephants in dryland systems in northern Namibia. Ecol Evol 2022; 12:e9288. [PMID: 36177134 PMCID: PMC9471278 DOI: 10.1002/ece3.9288] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 07/29/2022] [Accepted: 08/18/2022] [Indexed: 11/29/2022] Open
Abstract
Climatic variability, resource availability, and anthropogenic impacts heavily influence an animal's home range. This makes home range size an effective metric for understanding how variation in environmental factors alter the behavior and spatial distribution of animals. In this study, we estimated home range size of African elephants (Loxodonta africana) across four sites in Namibia, along a gradient of precipitation and human impact, and investigated how these gradients influence the home range size on regional and site scales. Additionally, we estimated the time individuals spent within protected area boundaries. The mean 50% autocorrelated kernel density estimate for home range was 2200 km2 [95% CI:1500–3100 km2]. Regionally, precipitation and vegetation were the strongest predictors of home range size, accounting for a combined 53% of observed variation. However, different environmental covariates explained home range variation at each site. Precipitation predicted most variation (up to 74%) in home range sizes (n = 66) in the drier western sites, while human impacts explained 71% of the variation in home range sizes (n = 10) in Namibia's portion of the Kavango‐Zambezi Transfrontier Conservation Area. Elephants in all study areas maintained high fidelity to protected areas, spending an average of 85% of time tracked on protected lands. These results suggest that while most elephant space use in Namibia is driven by natural dynamics, some elephants are experiencing changes in space use due to human modification.
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Affiliation(s)
- Lorena Benitez
- Smithsonian National Zoo & Conservation Biology Institute Front Royal Virginia USA
| | - J Werner Kilian
- Etosha Ecological Institute, Ministry of Environment, Forestry and Tourism Okaukuejo Namibia
| | - George Wittemyer
- Department of Fish, Wildlife, and Conservation Biology Colorado State University Fort Collins Colorado USA.,Save the Elephants Nairobi Kenya
| | - Lacey F Hughey
- Smithsonian National Zoo & Conservation Biology Institute Front Royal Virginia USA
| | - Chris H Fleming
- Smithsonian National Zoo & Conservation Biology Institute Front Royal Virginia USA.,Department of Biology University of Maryland Maryland USA
| | - Peter Leimgruber
- Smithsonian National Zoo & Conservation Biology Institute Front Royal Virginia USA
| | | | - Jared A Stabach
- Smithsonian National Zoo & Conservation Biology Institute Front Royal Virginia USA
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Garai ME, Roos T, Eggeling T, Ganswindt A, Pretorius Y, Henley M. Developing welfare parameters for African elephants (Loxodonta africana) in fenced reserves in South Africa. PLoS One 2022; 17:e0264931. [PMID: 35324916 PMCID: PMC8947097 DOI: 10.1371/journal.pone.0264931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 02/21/2022] [Indexed: 12/02/2022] Open
Abstract
South Africa has many fenced reserves harbouring small to medium sized populations of African elephant (Loxodonta africana), most of which have been translocated. Elephants on fenced reserves may be exposed to various management interventions and practices (translocation, hunting, darting, high tourism impact, contraception programs, disruption due to infrastructure maintenance, etc.). These factors may impact the welfare of elephants. Poor elephant welfare may have serious consequences such as increased inter- and intra-species aggression that could result in fatalities. This is the first study to attempt to define behavioural and physiological welfare parameters for free-ranging elephants on small to medium sized reserves. The eight study sites incorporated reserves with different social structure combinations, elephant life-histories, reserve sizes, habitat, management, and tourism intensity. Data collection consisted of behavioural observations (10-minute videos) as well as faecal samples. By incorporating both behavioural and physiological (faecal glucocorticoid metabolite (fGCM) concentration) parameters, we aimed to investigate whether the two parameters showed similar trends. Five behavioural categories were identified (Arousal, Assessing, Ambivalent, Ambivalent/ Body care, and Frustrated behaviour), with various detailed behaviours demonstrated by the elephants that may indicate the influence of anthropogenic disturbance and possibly impact on animal welfare. The study showed significant differences between the selected detailed behaviours, behavioural categories and fGCM concentrations of elephants across the eight reserves. History seemed to be a decisive factor, as reserves with predominantly ex-captive elephants showed higher frequencies of certain behaviours as well as higher fGCM concentrations. Age, sex, reserve size and season were also found to contribute to our defined welfare indices and fGCM concentrations. This indicates that behavioural parameters, indicative of certain behavioural states, are valuable indicators of welfare, as supported by the physiological response of the elephants. The results also highlight the importance of taking multiple specified behaviours from a category into consideration when evaluating the welfare of elephants, to account for individual variation.
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Affiliation(s)
| | - Tenisha Roos
- Elephant Reintegration Trust, Port Alfred, South Africa
| | | | - André Ganswindt
- Mammal Research Institute, University of Pretoria, Pretoria, South Africa
| | | | - Michelle Henley
- Applied Behavioural Ecology and Environmental Research Unit, University of South Africa, Pretoria, South Africa
- Elephants Alive, Hoedspruit, Limpopo, South Africa
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Effects of Positive Reinforcement Training and Novel Object Exposure on Salivary Cortisol Levels under Consideration of Individual Variation in Captive African Elephants ( Loxodonta africana). Animals (Basel) 2021; 11:ani11123525. [PMID: 34944300 PMCID: PMC8698154 DOI: 10.3390/ani11123525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 11/10/2021] [Accepted: 12/07/2021] [Indexed: 12/04/2022] Open
Abstract
Simple Summary Regular training for medical or enrichment purposes and the provision of environmental enrichment, such as varied feeding schedules and novel objects, are part of the management of African elephants in zoos. The present study aimed to find out whether training and enrichment in the form of a novel object induced physiological changes in captive African elephants. We repeatedly sampled the saliva of ten animals (three zoos) before and after training and the exposure to a novel object for the analysis of cortisol and as a measure of stress and arousal. We found high salivary cortisol levels before and low levels after training. A novel object, in contrast, moderately increased the salivary cortisol levels. Moreover, males and young elephants showed lower salivary cortisol levels than females and old elephants, respectively. The zoo, handling method (free vs. protected contact to keepers), reproductive and social status, however, did not influence the salivary cortisol levels of the animals studied. We conclude that the relatively high cortisol values before training could be due to anticipation of the training event. A novel object, in contrast, may have evoked arousal, which led to the observed cortisol increase. In addition, understanding why animals differ in stress responses will help to manage stress in zoo elephants with the goal of ensuring their welfare. Abstract Dealing with potential stress in species that have high husbandry requirements, such as elephants, is a challenge for zoos. The objective of the present study was to determine whether positive reinforcement training (PRT) and exposure to a novel object (NOV) for enrichment induced a salivary cortisol response indicative of activation of the hypothalamic–pituitary–adrenal (HPA) axis and which factors determine individual variation in this regard in captive African elephants. We repeatedly sampled the saliva of ten animals (three zoos) for the analysis of cortisol (SACort) before and up to 60 min (in 10–15 min intervals) after the onset of PRT (three repeats) or NOV (nine repeats), which lasted 10 min. There was considerable individual variation in SACort in response to PRT or NOV. Using mixed models, we were able to control these and to reveal that PRT was associated with high SACort before and relatively low SACort after PRT, while NOV induced a moderate SACort increase. The individual differences in SACort were related to age and sex (NOV), while the effects of zoo, handling method (free vs. protected contact) and reproductive and social status were variable. We conclude that positive affective states, such as anticipation or arousal, should be taken into account when interpreting the differences in the SACort responses between PRT and NOV. In addition, understanding the individuality of stress will support management decisions aimed at promoting captive elephant welfare.
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Athira TK, Vidya TNC. Elephant Social Systems: What Do We Know and How Have Molecular Tools Helped? J Indian Inst Sci 2021. [DOI: 10.1007/s41745-021-00226-4] [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]
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Flølo LM, Hunninck L, May R, Jackson CR, Setsaas TH, Holmern T, Røskaft E. Behavioural and demographic changes in impala populations after 15 years of improved conservation management. Glob Ecol Conserv 2021. [DOI: 10.1016/j.gecco.2021.e01586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Oduor S, Brown J, Macharia GM, Boisseau N, Murray S, Obade P. Differing physiological and behavioral responses to anthropogenic factors between resident and non-resident African elephants at Mpala Ranch, Laikipia County, Kenya. PeerJ 2020; 8:e10010. [PMID: 33062433 PMCID: PMC7528812 DOI: 10.7717/peerj.10010] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 08/31/2020] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Heterogeneous landscapes like those of Laikipia County, Kenya consist of a mosaic of land-use types, which may exert differential physiological effects on elephants that occupy and traverse them. Understanding behavioral and physiological states of wild African elephants in response to the challenges of living in human-dominated landscapes is therefore important for conservation managers to evaluate risks imposed by elephants to humans and vice versa. Several conservation physiology tools have been developed to assess how animals respond to both natural and anthropogenic changes, and determine biological impacts. This study investigated how migratory and avoidance behavioral to vehicle presence, and vegetation quality affected fecal glucocorticoid (GC) metabolite (FGM) concentrations in African elephants at Mpala Ranch, Laikipia County, Kenya. METHODS The study compared adrenal glucocorticoid activity of resident elephants that live within Mpala (n = 57) and non-resident elephants whose space use patterns overlap several ranches (n = 99) in Laikipia County, Kenya. Fecal samples were collected for a 4-month period between April and August for analysis of FGM concentrations. Behavioral reactions to research vehicles and body condition also were assessed. Satellite images from Terra Moderate Resolution Imaging (MODIS MOD13Q1) were downloaded and processed using Google Earth Engine to calculate a Normalized Difference Vegetation Index (NDVI) as a measure of vegetation quality. RESULTS As expected, there was a positive correlation between avoidance behavior to vehicle presence and FGM concentrations in both resident and non-resident elephants, whereas there was an inverse relationship between FGM concentrations and NDVI values. Our study also found a positive influence of age on the FGM concentrations, but there were no relationships between FGM and sex, social group type, herd size, and body condition. However, contrary to our expectations, resident elephants had higher FGM concentrations than non-residents. DISCUSSION Findings reveal elephants with stronger avoidance responses to research vehicles and resident elephants with relatively smaller home ranges exhibited higher FGM concentrations within the Mpala Ranch, Kenya and surrounding areas. Higher vegetative quality within the ranges occupied by non-resident elephants in Laikipia may be one reason for lower FGM, and an indication that the non-residents are tracking better forage quality to improve energy balance and reduce overall GC output. Additionally, our study found a positive influence of age, but no other demographic variables on FGM concentrations. Finally, adrenal glucocorticoid activity was inversely related to vegetative quality. Our findings can help conservation managers better understand how behavior and environment influences the physiological states of African elephants, and how management intervention might mitigate negative human-elephant interactions.
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Affiliation(s)
- Sandy Oduor
- Research, Mpala Research Centre, Nanyuki, Laikipia, Kenya
| | - Janine Brown
- Center for Species Survival, Smithsonian Conservation Biology Institute, Front Royal, VA, USA
| | - Geoffrey M. Macharia
- Department of Environmental Science, Kenyatta University, Nairobi, Nairobi, Kenya
| | - Nicole Boisseau
- Endocrine Lab, Smithsonian Conservation Biology Institute, Front Royal, VA, USA
| | - Suzan Murray
- Global Health Program, Smithsonian Conservation Biology Institute, Washington, DC, USA
| | - Paul Obade
- Department of Environmental Science, Kenyatta University, Nairobi, Nairobi, Kenya
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Hunninck L, May R, Jackson CR, Palme R, Røskaft E, Sheriff MJ. Consequences of climate-induced vegetation changes exceed those of human disturbance for wild impala in the Serengeti ecosystem. CONSERVATION PHYSIOLOGY 2020; 8:coz117. [PMID: 32477568 PMCID: PMC7246078 DOI: 10.1093/conphys/coz117] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 12/11/2019] [Accepted: 12/29/2019] [Indexed: 05/21/2023]
Abstract
In East Africa, climate change is predicted to reduce vegetation quality, and pervasive human disturbance has already resulted in significant declines in biodiversity. We studied the combined effects of reduced forage quality and human disturbance on faecal glucocorticoid metabolite (FGM) concentrations. We predicted that decreasing nutritional quality and increasing human disturbance would have an additive positive effect on FGM levels in wild impala (Aepyceros melampus). Employing a space-for-time approach, we used normalized difference vegetation index (NDVI) as a measure of forage quality, combined with spatially explicit proxies of human disturbance across areas of different protection management strategies in the Serengeti ecosystem. We collected 639 faecal samples, spread over 4 years, including both wet and dry seasons. Impala FGM levels increased significantly with declining NDVI and, to a lesser extent, with increasing proxies for human disturbance. However, we found no interaction between the two, such that impala had elevated FGM levels with low NDVI and low FGM levels with high NDVI regardless of human disturbance levels. This implies that impala will have high FGM levels if forage quality is poor, even with significant protection and reduced human disturbance. Understanding how animals respond to and cope with changes in forage quality and human land use across different protected areas is important for conservationists and managers to better protect species at risk and predict population viability.
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Affiliation(s)
- L Hunninck
- Department of Biology, Norwegian University of Science and
Technology, Høgskoleringen 5, 7034 Trondheim, Norway
- Corresponding author: NTNU, Høgskoleringen 1, 7491 Trondheim, Norway.
Tel: +47 474 43 361.
| | - R May
- Norwegian Institute for Nature Research, Høgskoleringen 9, 7034
Trondheim, Norway
| | - C R Jackson
- Norwegian Institute for Nature Research, Høgskoleringen 9, 7034
Trondheim, Norway
| | - R Palme
- Department of Biomedical Sciences, University of Veterinary
Medicine, Veterinärplatz 1, 1210 Vienna, Austria
| | - E Røskaft
- Department of Biology, Norwegian University of Science and
Technology, Høgskoleringen 5, 7034 Trondheim, Norway
| | - M J Sheriff
- Biology Department, University of Massachusetts, 285 Old Westport
Road, Dartmouth, MA 02747, USA
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Szott ID, Pretorius Y, Ganswindt A, Koyama NF. Physiological stress response of African elephants to wildlife tourism in Madikwe Game Reserve, South Africa. WILDLIFE RESEARCH 2020. [DOI: 10.1071/wr19045] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Abstract
ContextWildlife tourism has been shown to increase stress in a variety of species and can negatively affect survival, reproduction, welfare, and behaviour of individuals. In African elephants, Loxodonta africana, increased physiological stress has been linked to use of refugia, rapid movement through corridors, and heightened aggression towards humans. However, we are unaware of any studies assessing the impact of tourism pressure (tourist numbers) on physiological stress in elephants.
AimsWe used faecal glucocorticoid metabolite (fGCM) concentrations to investigate whether tourist numbers in Madikwe Game Reserve, South Africa, were related to changes in physiological stress in elephants.
MethodsWe repeatedly collected dung samples (n=43) from 13 individually identified elephants over 15 months. Using a generalised linear mixed model and a Kenward–Roger approximation, we assessed the impact of monthly tourist numbers, season, age, and sex on elephant fGCM concentrations.
Key resultsHigh tourist numbers were significantly related to elevated fGCM concentrations. Overall, fGCM concentrations increased by 112% (from 0.26 to 0.55µgg−1 dry weight) in the months with the highest tourist pressure, compared to months with the lowest tourist pressure.
ConclusionsManagers of fenced reserves should consider providing potential alleviation measures for elephants during high tourist pressure, for example, by ensuring that refuge areas are available. This may be of even higher importance if elephant populations have had traumatic experiences with humans in the past, such as poaching or translocation. Such management action will improve elephant welfare and increase tourist safety.
ImplicationsAlthough tourism can generate substantial revenue to support conservation action, careful monitoring of its impact on wildlife is required to manage potential negative effects.
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Gaynor KM, Branco PS, Long RA, Gonçalves DD, Granli PK, Poole JH. Effects of human settlement and roads on diel activity patterns of elephants (
Loxodonta africana
). Afr J Ecol 2018. [DOI: 10.1111/aje.12552] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Kaitlyn M. Gaynor
- Department of Environmental Science, Policy, and Management University of California Berkeley Berkeley California
| | - Paola S. Branco
- Department of Fish and Wildlife Sciences University of Idaho Moscow Idaho
| | - Ryan A. Long
- Department of Fish and Wildlife Sciences University of Idaho Moscow Idaho
| | - Dominique D. Gonçalves
- Department of Scientific Services Gorongosa National Park Gorongosa Mozambique
- Durrell Institute of Conservation and Ecology University of Kent Kent UK
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Setsaas T, Hunninck L, Jackson C, May R, Røskaft E. The impacts of human disturbances on the behaviour and population structure of impala (Aepyceros melampus) in the Serengeti ecosystem, Tanzania. Glob Ecol Conserv 2018. [DOI: 10.1016/j.gecco.2018.e00467] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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