1
|
Granweiler J, Cristóbal-Azkarate J, Morton N, Palme R, Shultz S. The paradox of spring: Thyroid and glucocorticoid responses to cold temperatures and food availability in free living Carneddau ponies. Horm Behav 2024; 161:105526. [PMID: 38503098 DOI: 10.1016/j.yhbeh.2024.105526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 02/20/2024] [Accepted: 02/29/2024] [Indexed: 03/21/2024]
Abstract
In seasonal environments, maintaining a constant body temperature poses challenges for endotherms. Cold winters at high latitudes, with limited food availability, create opposing demands on metabolism: upregulation preserves body temperature but depletes energy reserves. Examining endocrine profiles, such as thyroid hormone triiodothyronine (T3) and glucocorticoids (GCs), proxies for changes in metabolic rate and acute stressors, offer insights into physiological trade-offs. We evaluated how environmental conditions and gestation impact on faecal hormone metabolites (fT3Ms and fGCMs) from late winter to spring in a free-living population of Carneddau ponies. Faecal T3Ms were highest in late February and March, when temperatures were lowest. Then, fT3Ms concentrations decreased throughout April and were at the lowest in May before increasing towards the end of the study. The decline in fT3M levels in April and May was associated with warmer weather but poor food availability, diet diversity and diet composition. On the other hand, fGCM levels did not display a clear temporal pattern but were associated with reproductive status, where pregnant and lactating females had higher fGCM levels as compared to adult males and non-reproductive females. The temporal profile of fT3Ms levels highlights metabolic trade-offs in a changing environment. In contrast, the ephemeral but synchronous increase in fGCM concentrations across the population suggest a shared experience of acute stressors (i.e., weather, disturbance or social). This multi-biomarker approach can evaluate the role of acute stressors versus energy budgets in the context of interventions, reproduction, seasonality and environmental change, or across multiple scales from individuals to populations.
Collapse
Affiliation(s)
- Jessica Granweiler
- School of Earth and Environmental Sciences, The University of Manchester, Manchester, UK.
| | - Jurgi Cristóbal-Azkarate
- Department of Basic Psychological Processes and their Development, Faculty of Psychology, University of the Basque Country, Donostia, Spain
| | - Nathan Morton
- School of Earth and Environmental Sciences, The University of Manchester, Manchester, UK
| | - Rupert Palme
- Unit of Physiology, Pathophysiology and Experimental Endocrinology, Department of Biomedical Sciences, University of Veterinary Medicine, Vienna, Austria
| | - Susanne Shultz
- School of Earth and Environmental Sciences, The University of Manchester, Manchester, UK
| |
Collapse
|
2
|
Glucocorticoids of European Bison in Relation to Their Status: Age, Dominance, Social Centrality and Leadership. Animals (Basel) 2022; 12:ani12070849. [PMID: 35405836 PMCID: PMC8996974 DOI: 10.3390/ani12070849] [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: 02/14/2022] [Revised: 03/18/2022] [Accepted: 03/24/2022] [Indexed: 02/04/2023] Open
Abstract
Simple Summary This study quantified glucocorticoids in faeces of wild European bison and correlated it to different aspects of social status (leadership, age as a proxy of experience, dominance, social centrality) in order to better understand social mechanisms in this endangered species. Measurement of faecal glucocorticoid metabolites could thus be a valuable tool to follow and improve the adaptation and the welfare of herds in the semi-wild and in captivity by long-term following states of animals and changing conditions, according to them. Abstract Stress is the body’s response to cope with the environment and generally better survive unless too much chronic stress persists. While some studies suggest that it would be more stressful to be the dominant individual of the group, others support the opposite hypothesis. Several variables can actually affect this relationship, or even cancel it. This study therefore aims to make the link between social status and the basal level of stress of 14 wild European bison (Bison bonasus, L. 1758) living together. We collected faeces and measured the faecal glucocorticoid metabolites (FGM). We showed that FGM is linked to different variables of social status of European bison, specifically age, dominance rank, eigenvector centrality but also to interactions between the variables. Preferential leaders in bison, i.e., the older and more dominant individuals which are more central ones, are less stressed compared to other group members. Measurement of such variables could thus be a valuable tool to follow and improve the conservation of species by collecting data on FGM and other social variables and adapt group composition or environmental conditions (e.g., supplement in food) according to the FGM concentration of herd individuals.
Collapse
|
3
|
Effect of density and relative aggressiveness on agonistic and affiliative interactions in a newly formed group of horses. J Vet Behav 2019. [DOI: 10.1016/j.jveb.2018.03.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
4
|
Seeber PA, Quintard B, Sicks F, Dehnhard M, Greenwood AD, Franz M. Environmental stressors may cause equine herpesvirus reactivation in captive Grévy's zebras ( Equus grevyi). PeerJ 2018; 6:e5422. [PMID: 30155350 PMCID: PMC6109370 DOI: 10.7717/peerj.5422] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 07/20/2018] [Indexed: 12/15/2022] Open
Abstract
Equine Herpesviruses (EHV) are common and often latent pathogens of equids which can cause fatalities when transmitted to non-equids. Stress and elevated glucocorticoids have been associated with EHV reactivation in domestic horses, but little is known about the correlation between stress and viral reactivation in wild equids. We investigated the effect of an environmental stressor (social group restructuring following a translocation event) on EHV reactivation in captive Grévy's zebras (Equus grevyi). A mare was translocated by road transport from Zoo Mulhouse, France, to join a resident group of three mares in Tierpark Berlin, Germany. We used an indirect sampling method to assess the frequency of EHV shedding for 14 days immediately after the translocation event (termed the 'experimental period'). The results were compared with those from two control periods, one preceding and one subsequent to the experimental period. In addition, we measured fecal glucocorticoid metabolite (fGCM) concentrations daily in all individuals from 6 days before, to 14 days after translocation. We found significantly higher EHV shedding frequencies during the experimental period, compared to each of the two control periods. All animals showed significantly elevated fGCM concentrations, compared to fGCM levels before translocation. Finally, we found that an increase in fGCM concentration was significantly associated with an increased likelihood of EHV shedding. Although the small number of animals in the study limits the conclusions that can be drawn from the study, taken together, our results support the hypothesis that environmental stressors induce viral reactivation in wild equids. Our results suggest that potentials stressors such as group restructuring and translocation should be considered in the management of zoological collections to reduce the risk of fatal EHV infections in novel hosts. Moreover, environmental stressors may play an important role in EHV reactivation and spread in wild equid populations.
Collapse
Affiliation(s)
- Peter A. Seeber
- Department of Wildlife Diseases, Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany
| | | | | | - Martin Dehnhard
- Department of Reproduction Biology, Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany
| | - Alex D. Greenwood
- Department of Wildlife Diseases, Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany
- Department of Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
| | - Mathias Franz
- Department of Wildlife Diseases, Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany
| |
Collapse
|
5
|
Seeber PA, Franz M, Dehnhard M, Ganswindt A, Greenwood AD, East ML. Plains zebra (Equus quagga) adrenocortical activity increases during times of large aggregations in the Serengeti ecosystem. Horm Behav 2018; 102:1-9. [PMID: 29630896 DOI: 10.1016/j.yhbeh.2018.04.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 03/19/2018] [Accepted: 04/03/2018] [Indexed: 11/25/2022]
Abstract
Adverse environmental stimuli (stressors) activate the hypothalamic-pituitary-adrenal axis and contribute to allostatic load. This study investigates the contribution of environmental stressors and life history stage to allostatic load in a migratory population of plains zebras (Equus quagga) in the Serengeti ecosystem, in Tanzania, which experiences large local variations in aggregation. We expected higher fGCM response to the environmental stressors of feeding competition, predation pressure and unpredictable social relationships in larger than in smaller aggregations, and in animals at energetically costly life history stages. As the study was conducted during the 2016 El Niño, we did not expect food quality of forage or a lack of water to strongly affect fGCM responses in the dry season. We measured fecal glucocorticoid metabolite (fGCM) concentrations using an enzyme immunoassay (EIA) targeting 11β-hydroxyetiocholanolone and validated its reliability in captive plains zebras. Our results revealed significantly higher fGCM concentrations 1) in large aggregations than in smaller groupings, and 2) in band stallions than in bachelor males. Concentrations of fGCM were not significantly higher in females at the energetically costly life stage of late pregnancy/lactation. The higher allostatic load of stallions associated with females, than bachelor males is likely caused by social stressors. In conclusion, migratory zebras have elevated allostatic loads in large aggregations that probably result from their combined responses to increased feeding competition, predation pressure and various social stressors. Further research is required to disentangle the contribution of these stressors to allostatic load in migratory populations.
Collapse
Affiliation(s)
- P A Seeber
- Leibniz-Institute for Zoo and Wildlife Research, Alfred-Kowalke-Strasse 17, 10315 Berlin, Germany
| | - M Franz
- Leibniz-Institute for Zoo and Wildlife Research, Alfred-Kowalke-Strasse 17, 10315 Berlin, Germany
| | - M Dehnhard
- Leibniz-Institute for Zoo and Wildlife Research, Alfred-Kowalke-Strasse 17, 10315 Berlin, Germany
| | - A Ganswindt
- Endocrine Research Laboratory, Department of Anatomy and Physiology, Faculty of Veterinary Science, University of Pretoria, Private Bag XO4, Onderstepoort 0110, South Africa; Mammal Research Institute, Department of Zoology and Entomology, Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria 0028, South Africa
| | - A D Greenwood
- Leibniz-Institute for Zoo and Wildlife Research, Alfred-Kowalke-Strasse 17, 10315 Berlin, Germany; Department of Veterinary Medicine, Freie Universität Berlin, Berlin, Germany.
| | - M L East
- Leibniz-Institute for Zoo and Wildlife Research, Alfred-Kowalke-Strasse 17, 10315 Berlin, Germany
| |
Collapse
|
6
|
Cassidy KA, Mech LD, MacNulty DR, Stahler DR, Smith DW. Sexually dimorphic aggression indicates male gray wolves specialize in pack defense against conspecific groups. Behav Processes 2017; 136:64-72. [PMID: 28143722 DOI: 10.1016/j.beproc.2017.01.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Revised: 11/25/2016] [Accepted: 01/18/2017] [Indexed: 10/20/2022]
Abstract
Aggression directed at conspecific groups is common among gregarious, territorial species, and for some species such as gray wolves (Canis lupus) intraspecific strife is the leading cause of natural mortality. Each individual in a group likely has different measures of the costs and benefits associated with a group task, such as an aggressive attack on another group, which can alter motivation and behavior. We observed 292 inter-pack aggressive interactions in Yellowstone National Park between 1 April 1995 and 1 April 2011 (>5300days of observation) in order to determine the role of both sexes, and the influence of pack, age, and other traits on aggression. We recorded the behaviors and characteristics of all individuals present during the interactions (n=534 individuals) and which individuals participated in each step (i.e. chase, attack, kill, flight) of the interaction. Overall, all wolves were more likely to chase rivals if they outnumbered their opponent, suggesting packs accurately assess their opponent's size during encounters and individuals adjust their behavior based on relative pack size. Males were more likely than females to chase rival packs and gray-colored wolves were more aggressive than black-colored wolves. Male wolves and gray-colored wolves also recorded higher cortisol levels than females and black-colored wolves, indicating hormonal support for more intense aggressive behavior. Further, we found a positive correlation between male age and probability of chasing, while age-specific participation for females remained constant. Chasing behavior was influenced by the sex of lone intruders, with males more likely to chase male intruders. This difference in behavior suggests male and female wolves may have different strategies and motivations during inter-pack aggressive interactions related to gray wolf mating systems. A division of labor between pack members concerning resource and territory defense suggests selection for specific traits related to aggression is an adaptive response to intense competition between groups of conspecifics.
Collapse
Affiliation(s)
- Kira A Cassidy
- Natural Resource Science and Management, 115 Green Hall, 1530 Cleveland Avenue N, University of Minnesota, St. Paul, MN, 55108, USA; Yellowstone Wolf Project, PO Box 168, Yellowstone Center for Resources, Yellowstone National Park, WY, 82190, USA.
| | - L David Mech
- U. S. Geological Survey, Northern Prairie Wildlife Research Center, 8711-37th St., S.E., Jamestown, ND, 58401-7317, USA
| | - Daniel R MacNulty
- Department of Wildland Resources, Utah State University, Logan, UT, 84322, USA
| | - Daniel R Stahler
- Yellowstone Wolf Project, PO Box 168, Yellowstone Center for Resources, Yellowstone National Park, WY, 82190, USA
| | - Douglas W Smith
- Yellowstone Wolf Project, PO Box 168, Yellowstone Center for Resources, Yellowstone National Park, WY, 82190, USA
| |
Collapse
|