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Burger M, Webster AB, Majelantle TL, Scheun J, Ganswindt A. Method development: Assigning sex to African clawless otter spraints and assessing stability of faecal androgen and progestagen metabolites post-defaecation. MethodsX 2024; 13:102883. [PMID: 39206057 PMCID: PMC11350257 DOI: 10.1016/j.mex.2024.102883] [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: 06/12/2024] [Accepted: 07/30/2024] [Indexed: 09/04/2024] Open
Abstract
Monitoring reproductive physiology in wildlife can be a useful tool for assessing population dynamics for conservation and management purposes. Utilizing non-invasive approaches for this, such as quantifying reproductive hormone metabolites from faeces, can be challenging when defaecation events are not observed, or when cryptic species like African clawless otters (Aonyx capensis) are involved. Additionally, test systems for quantifying hormone metabolites in a species for the first time must first be reliably validated prior to use. Our results indicate that Epiandrosterone and Progesterone EIAs are most suitable for determining fAM and fPM concentrations in African clawless otter spraints. The fAM:fPM ratio and respective thresholds are more reliable in sex identification compared to the separate use of individual hormone classes. Sex-related hormone metabolite concentrations remained comparable for up to 12hrs post-defaecation in both sexes.•We screened two androgen and two progestagen enzyme-immunoassays (EIAs) for suitability and reliable quantification of faecal androgen metabolites (fAM) and faecal progestagen metabolites (fPM) in African clawless otters.•We assessed whether the ratio of fAM:fPM concentrations can be used to assign sex to faecal samples from unknown individuals.•We tested the stability of fAM and fPM concentrations post-defaecation to determine the effects of environmental exposure and bacterial metabolism.
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Affiliation(s)
- Marli Burger
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
- Endocrine Research Laboratory, Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria, South Africa
| | - Andrea B. Webster
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
- Endocrine Research Laboratory, Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria, South Africa
| | - Tshepiso L. Majelantle
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
- Endocrine Research Laboratory, Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria, South Africa
| | - Juan Scheun
- Department Nature Conservation, Tshwane University of Technology, Pretoria, South Africa
| | - Andre Ganswindt
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
- Endocrine Research Laboratory, Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria, South Africa
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Fowler KJ, Santymire RM. A novel field method for preserving African lion (Panthera leo) fecal samples for noninvasive hormone metabolite analysis,. MethodsX 2022; 9:101881. [PMID: 36385914 PMCID: PMC9641247 DOI: 10.1016/j.mex.2022.101881] [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: 07/21/2022] [Accepted: 10/07/2022] [Indexed: 11/06/2022] Open
Abstract
The traditional methods of preserving fecal samples to suspend hormone-degrading bacteria are not always options during remote fieldwork when studying wildlife endocrinology. Our goal was to develop a field method for preserving African lion (Panthera leo) feces for hormone metabolite analysis by determining the stability of fecal hormone metabolites: 1) when exposed to the natural environment, and 2) in silica beads at ambient temperatures. We collected fresh feces from zoo-housed lions and combined them into two (male and female) homogenous samples. Each was divided into eight samples to undergo a cross-designed treatment.We immediately lyophilized one sample to serve as the control. We then exposed seven samples outside to natural environmental conditions for 0, 12, 24, 36, 48, 60, or 72 h. After outdoor exposure, we desiccated a subsample in silica beads for an additional 5, 7, or 10 days. We analyzed the fecal hormone metabolite concentrations in each sample using enzyme immunoassays for corticosterone, cortisol, testosterone, progesterone, and estradiol. We determined that male and female fecal hormone metabolites in fresh African lion fecal samples are stable and comparable to a standardized desiccation method if dried in silica beads for 5 to 10 days prior to storing them at -20℃.
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Affiliation(s)
- Katherine J. Fowler
- Department of Biological Sciences, University of Illinois at Chicago, 845 W. Taylor Street, Chicago, IL 60607, United States
- Corresponding author.
| | - Rachel M. Santymire
- Department of Biological Sciences, University of Illinois at Chicago, 845 W. Taylor Street, Chicago, IL 60607, United States
- Biology Department, Georgia State University, Atlanta, GA, United States
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Carlin E, J. Somers M, Scheun J, Campbell R, Ganswindt A. Quantification of faecal glucocorticoid metabolites as a measure of stress in the rock hyrax
Procavia capensis
living in an urban green space. WILDLIFE BIOLOGY 2021. [DOI: 10.1002/wlb3.01011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- E. Carlin
- Mammal Research Inst., Dept of Zoology and Entomology, Univ. of Pretoria Pretoria South Africa
| | - M. J. Somers
- Mammal Research Inst., Dept of Zoology and Entomology, Univ. of Pretoria Pretoria South Africa
- Centre for Invasion Biology, Univ. of Pretoria Pretoria South Africa
| | - J. Scheun
- Mammal Research Inst., Dept of Zoology and Entomology, Univ. of Pretoria Pretoria South Africa
- Dept of Life and Consumer Sciences, Univ. of South Africa Pretoria South Africa
| | - R. Campbell
- National Zoological Garden, South African National Biodiversity Inst. Pretoria South Africa
| | - A. Ganswindt
- Mammal Research Inst., Dept of Zoology and Entomology, Univ. of Pretoria Pretoria South Africa
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Dalerum F, Ganswindt A, Palme R, Bettega C, Delgado MDM, Dehnhard M, Freire S, González RG, Marcos J, Miranda M, Vázquez VM, Corominas TS, Huerta JT, Zedrosser A, Ordiz A, Penteriani V. Methodological Considerations for Using Fecal Glucocorticoid Metabolite Concentrations as an Indicator of Physiological Stress in the Brown Bear ( Ursus arctos). Physiol Biochem Zool 2020; 93:227-234. [PMID: 32228370 DOI: 10.1086/708630] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Reliable methods to measure stress-related glucocorticoid responses in free-ranging animals are important for wildlife management and conservation. Such methods are also paramount for our ability to improve our knowledge of the ecological consequences of physiological processes. The brown bear (Ursus arctos) is a large carnivore of ecological and cultural importance and is important for management. Here, we provide a physiological validation for an enzyme immunoassay (EIA) to quantify glucocorticoid metabolites in brown bear feces. We also provide an evaluation of the effects of sample exposure to ambient temperature on measured fecal glucocorticoid metabolite (fGCM) concentrations. We evaluated three EIA systems: a cortisol assay, an 11-oxoetiocholanolone assay, and an 11β-hydroxyetiocholanolone assay. Of these, the cortisol assay provided the best discrimination between peak fGCM concentrations detected 1-4 d after injections of synthetic adrenocorticotrophic hormone and preinjection baseline concentrations in four individual brown bears. The time of exposure to ambient temperature had substantial but variable effects on measured fGCM concentrations, including variation both between samples from the same individual and among samples from different bears. We propose that the validated EIA system for measuring fGCM concentrations in the brown bear could be a useful noninvasive method to monitor stress in this species. However, we highlight that this method requires that fecal samples be frozen immediately after defecation, which could be a limitation in many field situations.
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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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Majelantle TL, McIntyre T, Ganswindt A. Monitoring the effects of land transformation on African clawless otters (Aonyx capensis) using fecal glucocorticoid metabolite concentrations as a measure of stress. Integr Zool 2020; 15:293-306. [PMID: 31912606 DOI: 10.1111/1749-4877.12428] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
In a time of increasing environmental change caused by anthropogenic disturbance, there is a greater need to understand animal adaptations to manmade environments. In this regard, the measurement of stress-related endocrine markers provides a useful tool to examine the impact of environmental challenges and the physiological consequences for wildlife occupying such space. The aims of the present study were to validate fecal glucocorticoid metabolite (fGCM) concentrations as a measure of stress using samples from a male African clawless otter (Aonyx capensis; n = 1) and to compare fGCM concentrations of otters occurring in a transformed and in 2 natural areas in South Africa. From the 5 different enzyme-immunoassays (EIA) tested, a cortisol and oxoetiocholanolone (measuring 11,17 dioxoandrostanes) EIA revealed the highest response (74% and 48% increase, respectively) 30 and 24 hours after a stress event (translocation of a captive individual as part of its rehabilitation prior to release), respectively. For both EIAs, fGCM concentrations were comparable for samples collected up to 3 h post-defecation. Using the cortisol EIA for subsequent analyses, fGCM concentrations of animals from the transformed area (n = 20; mean [± SD]: 0.468 [± 0.539] µg/g dry weight [DW]) were significantly higher (P = 0.013) than those from otters in the natural areas (n = 17; 0.242 [± 0.226] µg/g DW). These preliminary results suggest that African clawless otters may have increased adrenocortical activity that could be due to conditions linked to living in a transformed environment.
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Affiliation(s)
- Tshepiso L Majelantle
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
| | - Trevor McIntyre
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa.,Department of Life and Consumer Sciences, University of South Africa, Pretoria, South Africa
| | - Andre Ganswindt
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa.,Endocrine Research Laboratory, Department of Anatomy and Physiology, University of Pretoria, Onderstepoort, South Africa.,Centre for Veterinary Wildlife Studies, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa
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Non-Invasive Assessment of Body Condition and Stress-Related Fecal Glucocorticoid Metabolite Concentrations in African Elephants ( Loxodonta africana) Roaming in Fynbos Vegetation. Animals (Basel) 2020; 10:ani10050814. [PMID: 32397066 PMCID: PMC7278398 DOI: 10.3390/ani10050814] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 04/22/2020] [Accepted: 04/27/2020] [Indexed: 11/17/2022] Open
Abstract
Simple Summary The Western Cape Province of South Africa is characterized by Fynbos vegetation. This unique endemic vegetation type belongs to the Cape Floral Kingdom, the smallest of the six floral kingdoms in the world, and only a few provincial, national and private game reserves in this area currently support populations of African elephants (Loxodonta africana). As a result, not much is known about the ability of elephants to thrive in such a unique environment. External factors such as a nutritionally poor diet can be perceived as a stressor by mammals, and establishing links between these two factors was the focus of this study. The results of monitoring individual stress-related hormone levels and body conditions suggest that elephants can obtain adequate nutrition from Fynbos vegetation. Abstract Fynbos is a unique endemic vegetation type belonging to the Cape Floral Kingdom in the Western Cape Province of South Africa, representing the smallest of the six floral kingdoms in the world. Nowadays, only a few game reserves in this region support populations of African elephants (Loxodonta africana), and thus, little information exists regarding the suitability of the nutritionally poor Fynbos vegetation for these megaherbivores. Using already established non-invasive methods, the monitoring of individual body conditions and fecal glucocorticoid metabolite (fGCM) concentrations, as a measure of physiological stress, was performed to examine a herd of 13 elephants in a Western Cape Province Private Game Reserve, during two monitoring periods (April and June 2018), following a severe drought. The results indicate that overall median body condition scores (April and June: 3.0, range 2.0–3.0) and fGCM concentrations (April: 0.46 µg/g dry weight (DW), range 0.35–0.66 µg/g DW; June: 0.61 µg/g DW, range 0.22–1.06 µg/g DW) were comparable to those of other elephant populations previously studied utilizing the same techniques. These findings indicate that the individuals obtain sufficient nutrients from the surrounding Fynbos vegetation during the months monitored. However, a frequent assessment of body conditions and stress-associated fGCM concentrations in these animals would assist conservation management authorities and animal welfare practitioners in determining ways to manage this species in environments with comparably poorer nutritional vegetation.
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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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