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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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2
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Tuomi MW, Murguzur FJA, Hoset KS, Soininen EM, Vesterinen EJ, Utsi TA, Kaino S, Bråthen KA. Novel frontier in wildlife monitoring: Identification of small rodent species from fecal pellets using near-infrared reflectance spectroscopy (NIRS). Ecol Evol 2023; 13:e9857. [PMID: 36950367 PMCID: PMC10024998 DOI: 10.1002/ece3.9857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 01/13/2023] [Accepted: 02/03/2023] [Indexed: 03/21/2023] Open
Abstract
Small rodents are prevalent and functionally important across the world's biomes, making their monitoring salient for ecosystem management, conservation, forestry, and agriculture. There is a growing need for cost-effective and noninvasive methods for large-scale, intensive sampling. Fecal pellet counts readily provide relative abundance indices, and given suitable analytical methods, feces could also allow for the determination of multiple ecological and physiological variables, including community composition. In this context, we developed calibration models for rodent taxonomic determination using fecal near-infrared reflectance spectroscopy (fNIRS). Our results demonstrate fNIRS as an accurate and robust method for predicting genus and species identity of five coexisting subarctic microtine rodent species. We show that sample exposure to weathering increases the method's accuracy, indicating its suitability for samples collected from the field. Diet was not a major determinant of species prediction accuracy in our samples, as diet exhibited large variation and overlap between species. fNIRS could also be applied across regions, as calibration models including samples from two regions provided a good prediction accuracy for both regions. We show fNIRS as a fast and cost-efficient high-throughput method for rodent taxonomic determination, with the potential for cross-regional calibrations and the use on field-collected samples. Importantly, appeal lies in the versatility of fNIRS. In addition to rodent population censuses, fNIRS can provide information on demography, fecal nutrients, stress hormones, and even disease. Given the development of such calibration models, fNIRS analytics could complement novel genetic methods and greatly support ecosystem- and interaction-based approaches to monitoring.
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Affiliation(s)
- Maria W. Tuomi
- Department of Arctic and Marine BiologyUiT The Arctic University of NorwayTromsøNorway
- Section of EcologyDepartment of BiologyUniversity of TurkuTurkuFinland
| | | | - Katrine S. Hoset
- Section of EcologyDepartment of BiologyUniversity of TurkuTurkuFinland
| | - Eeva M. Soininen
- Department of Arctic and Marine BiologyUiT The Arctic University of NorwayTromsøNorway
| | - Eero J. Vesterinen
- Department of EcologySwedish University of Agricultural SciencesUppsalaSweden
- Biodiversity UnitUniversity of TurkuTurkuFinland
- Department of Agricultural SciencesUniversity of HelsinkiHelsinkiFinland
| | - Tove Aa. Utsi
- Department of Arctic and Marine BiologyUiT The Arctic University of NorwayAltaNorway
| | - Sissel Kaino
- Department of Arctic and Marine BiologyUiT The Arctic University of NorwayTromsøNorway
| | - Kari Anne Bråthen
- Department of Arctic and Marine BiologyUiT The Arctic University of NorwayTromsøNorway
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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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Santamaria F, Schlagloth R, Palme R, Henning J. Over Time Decay of Cortisol Metabolites in Faecal Pellets of Koalas in Central Queensland. Animals (Basel) 2021; 11:ani11123376. [PMID: 34944153 PMCID: PMC8698095 DOI: 10.3390/ani11123376] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 11/22/2021] [Accepted: 11/23/2021] [Indexed: 11/27/2022] Open
Abstract
Simple Summary Faecal cortisol metabolites (FCMs) are a useful, non-invasive tool for the assessment of stress in koalas. However, FCM stability after defecation is a critical issue. Therefore, we exposed faecal pellets of koalas to three different environmental conditions and measured FCMs with three recently evaluated enzyme immunoassays (EIAs). Because water loss over time exerted the greatest influence on FCMs, we strongly recommend collecting freshly defecated pellets in koalas. Abstract Faecal material can be a valuable source of information for a range of animal health aspects and can be used to measure faecal cortisol metabolites (FCMs). FCM values can relate to physiological stress responses. However, freshly defecated pellets are not always available and environmental conditions, such as temperature and humidity, might affect faecal pellet consistency and FCM levels. Therefore, the impact of environmental conditions on FCMs needs to be evaluated. We collected 107 pellets from two female and two male koalas, exposed them to three types of treatments, and analysed FCMs in these samples with three enzyme immunoassays (EIAs). After analysis, the original FCM values were mathematically corrected for water loss. Results show that the FCMs were more stable when measured using tetrahydrocorticosterone (50c) and 5α-pregnane-3β,11β,21-triol-20-one (37e) EIAs, and were less stable when measured with the cortisol EIA. With 50c, the FCM values did not vary significantly over time either before or after the adjustment with water in the environment treatment group. For samples kept under constant low (25 °C) and high (35 °C) temperatures, the 50c FCM values did not vary significantly over time, after adjustments were made for water loss. Thus, this study highlights the importance of considering the suitability of faecal field samples for FCM analysis. Because water loss was the main driver of FCM changes, we strongly recommend collecting koala pellets that are freshly defecated, despite the effort and time it might take to collect such pellets.
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Affiliation(s)
- Flavia Santamaria
- Koala Research-Central Queensland and Flora, Fauna and Freshwater Research, School of Health, Medical and Applied Sciences, Central Queensland University, North Rockhampton, QLD 4702, Australia;
- Correspondence:
| | - Rolf Schlagloth
- Koala Research-Central Queensland and Flora, Fauna and Freshwater Research, School of Health, Medical and Applied Sciences, Central Queensland University, North Rockhampton, QLD 4702, Australia;
| | - Rupert Palme
- Department of Biomedical Sciences, University of Veterinary Medicine, 1210 Vienna, Austria;
| | - Joerg Henning
- School of Veterinary Science, The University of Queensland, Gatton, QLD 4343, Australia;
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Rabon J, Nuñez C, Coates P, Ricca M, Johnson T. Ecological correlates of fecal corticosterone metabolites in female Greater Sage-Grouse (Centrocercus urophasianus). CAN J ZOOL 2021. [DOI: 10.1139/cjz-2020-0258] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Measurement of physiological responses can reveal effects of ecological conditions on an animal and correlate with demographic parameters. Ecological conditions for many animal species have deteriorated as a function of invasive plants and habitat fragmentation. Expansion of juniper (genus Juniperus L.) trees and invasion of annual grasses into sagebrush (genus Artemisia L.) ecosystems have contributed to habitat degradation for Greater Sage-Grouse (Centrocercus urophasianus (Bonaparte, 1827); hereinafter Sage-Grouse), a species of conservation concern throughout its range. We evaluated relationships between habitat use in a landscape modified by juniper expansion and annual grasses and corticosterone metabolite levels (stress responses) in feces (FCORTm) of female Sage-Grouse. We used remotely sensed data to estimate vegetation cover within the home ranges of hens and accounted for factors that influence FCORTm in other vertebrates, such as age and weather. We collected 35 fecal samples from 22 radio-collared hens during the 2017–2018 brood-rearing season (24 May–26 July) in southwestern Idaho (USA). Concentrations of corticosterone increased with home range size but decreased with reproductive effort and temperature. The importance of home range size suggests that maintaining or improving habitats that promote smaller home ranges would likely facilitate a lower stress response by hens, which should benefit Sage-Grouse survival and reproduction.
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Affiliation(s)
- J.C. Rabon
- University of Idaho, 875 Perimeter Drive MS 1136, Moscow, ID 83844-1136, USA
| | - C.M.V. Nuñez
- University of Memphis, 3774 Walker Avenue, Memphis, TN 38152, USA
| | - P.S. Coates
- Western Ecological Research Center, U.S. Geological Survey, 800 Business Park Drive, Dixon, CA 95620, USA
| | - M.A. Ricca
- Forest and Rangeland Ecosystem Science Center, U.S. Geological Survey, 777 Northwest Ninth Street #400, Corvallis, OR 97330, USA
| | - T.N. Johnson
- University of Idaho, 875 Perimeter Drive MS 1136, Moscow, ID 83844-1136, USA
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Sergiel A, Barja I, Navarro-Castilla Á, Zwijacz-Kozica T, Selva N. Losing seasonal patterns in a hibernating omnivore? Diet quality proxies and faecal cortisol metabolites in brown bears in areas with and without artificial feeding. PLoS One 2020; 15:e0242341. [PMID: 33180870 PMCID: PMC7660533 DOI: 10.1371/journal.pone.0242341] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 11/01/2020] [Indexed: 11/19/2022] Open
Abstract
Bears are omnivores particularly well-adapted to variations in the nutritional composition, quality and availability of food resources. Artificial feeding practices have been shown to strongly influence diet composition and seasonality, as well as to cause alterations in wintering and movement in brown bears (Ursus arctos). In this study, we investigated seasonal differences (hypophagia vs hyperphagia) in food quality of two brown bear subpopulations in the Polish Carpathians using faecal nitrogen (FN) and carbon (FC) estimates. The subpopulations inhabit areas that differ in artificial feeding practices: no artificial feeding occurs in the western subpopulation (Tatra Mountains), while artificial food targeted to ungulates is provided and used year-round in the eastern subpopulation (Bieszczady Mountains). We also compared these results with faecal cortisol metabolites (FCM) to explore how FN and FC correlate with the hypothalamic-pituitary-adrenal axis activity and if the seasonal patterns are apparent. We found that in Tatra Mts bears fed on significantly higher quality diet, as shown by FN and FC values, and had significantly higher FC levels in hyperphagia, when they accumulate fat reserves for wintering. The pattern in FCM levels for Tatra subpopulation followed the changes in energy intake during the seasons of hypo- and hyperphagia, while in Bieszczady Mts, the area with intensive feeding, no seasonal patterns could be observed. Artificial feeding practices may disrupt nutrient phenology and seasonality, relative to subpopulations with natural diets. We showed that the availability of human-provided foods may alter not only the overall dietary quality, but also hormonal patterns linked to seasonal nutritional requirements. Combining FN, FC and FCM proved to be a useful tool for reconstructing diet quality and related physiological patterns.
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Affiliation(s)
- Agnieszka Sergiel
- Institute of Nature Conservation, Polish Academy of Sciences, Krakow, Poland
- * E-mail:
| | - Isabel Barja
- Department of Biology, Universidad Autónoma de Madrid, Madrid, Spain
- Centro de Investigación en Biodiversidad y Cambio Global (CIBC-UAM) Universidad Autónoma de Madrid, Madrid, Spain
| | | | | | - Nuria Selva
- Institute of Nature Conservation, Polish Academy of Sciences, Krakow, Poland
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7
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Prado-Ortiz LE, Valdespino C, Romano M, González-Romero A. Quantification of immunoreactive testosterone and estradiol-17ß metabolites to identify the sex of Neotropical otters (Lontra longicaudis annectens) in the field. Anim Reprod Sci 2020; 222:106607. [PMID: 33017800 DOI: 10.1016/j.anireprosci.2020.106607] [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] [Received: 02/14/2020] [Revised: 09/14/2020] [Accepted: 09/15/2020] [Indexed: 01/24/2023]
Abstract
Before there was use of ultrasonographic imaging, determination of the ratio of estrogens to androgens in the same individual was a technique used for differentiating the sex of monomorphic animals in captivity, with larger estrogen concentrations in the females. Due to species-specific differences in both concentration and changes throughout the year of these hormones, corroboration of the method is needed in each case. In this study, there was use of a chemo-immuno assay to quantify sex steroids in fecal samples collected from seven (five females and two males) Neotropical otters, Lontra longicaudis. The reproductive season for this species was determined to be between October and March, with increased estradiol in the females and relatively greater concentrations of testosterone in the males as compared with other seasons of the year. Results from utilization of a k-means analysis procedure indicated that the use of steroid ratios in fecal samples to differentiate otter sex is an effective technique when there are evaluations during the breeding season. The estrogen to androgen ratios during this period, however, are the inverse of what was expected, with there being larger testosterone concentrations in the female otters. The ratio of estrogens to androgens in feces of captive otters can be effectively used to determine the sex of otters in the field. We propose this method is reliable for sex determination in wild otter populations during the reproductive season.
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Affiliation(s)
- L E Prado-Ortiz
- Red de Biología y Conservación de Vertebrados, Instituto de Ecología A. C., Carretera Antigua a Coatepec # 351, El haya, 91070 Xalapa, Veracruz, Mexico
| | - C Valdespino
- Red de Biología y Conservación de Vertebrados, Instituto de Ecología A. C., Carretera Antigua a Coatepec # 351, El haya, 91070 Xalapa, Veracruz, Mexico.
| | - M Romano
- D. Fisiología, Biofísica y Neurociencias, CINVESTAV, Mexico
| | - A González-Romero
- Red de Biología y Conservación de Vertebrados, Instituto de Ecología A. C., Carretera Antigua a Coatepec # 351, El haya, 91070 Xalapa, Veracruz, Mexico
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8
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Scherpenhuizen JM, Narayan EJ, Quinn JC. Timed environmental exposure indicates sample stability for reliable noninvasive measurement of fecal cortisol metabolite concentrations in sheep. Domest Anim Endocrinol 2020; 72:106423. [PMID: 32272317 DOI: 10.1016/j.domaniend.2019.106423] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 10/26/2019] [Accepted: 12/03/2019] [Indexed: 10/25/2022]
Abstract
The use of noninvasive techniques to evaluate stress responses in animals has become an increasingly popular method of animal welfare assessment in both production animals and wildlife. In particular, using fecal samples to measure fecal cortisol metabolites (FCMs) as a quantitative measure has proven ideal as samples can be collected remote to the animal after defecation without the need for invasive procedures. Colorimetric enzyme immunoassays (EIAs) have been shown to have a high level of selectivity and sensitivity for FCM concentration analysis, equivalent to the traditionally used radioimmunoassay. Regardless of the assay system used, species- and sample-specific validation must be undertaken to ensure the reliability of results, particularly where sampling is undertaken in a novel species or where environmental conditions might impact FCM stability in the fecal sample. To determine the limit of environmental exposure acceptable for analysis of FCM concentrations in ovine scat samples collected from a paddock under conditions of stable heat and humidity, this study quantified FCMs in ovine feces shortly after defecation (2-7 h) and after timed environmental exposure (1-9 d). Samples were determined to show stable FCM concentrations for up to 5 d by this analysis. Understanding the impacts of environmental exposure, and therefore the viability of remote fecal collection methods for quantitative analysis of FCM by EIA, is important to assess the utility of noninvasive measures of endocrine status in animals where the exact timing of defecation may not be known.
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Affiliation(s)
- J M Scherpenhuizen
- School of Animal and Veterinary Sciences, Charles Sturt University, Wagga Wagga, New South Wales 2678, Australia; Graham Centre for Agricultural Innovation (Charles Sturt University and NSW Department of Primary Industries), Wagga Wagga, New South Wales 2560, Australia.
| | - E J Narayan
- School of Animal and Veterinary Sciences, Charles Sturt University, Wagga Wagga, New South Wales 2678, Australia
| | - J C Quinn
- School of Animal and Veterinary Sciences, Charles Sturt University, Wagga Wagga, New South Wales 2678, Australia; Graham Centre for Agricultural Innovation (Charles Sturt University and NSW Department of Primary Industries), Wagga Wagga, New South Wales 2560, Australia
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9
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Parikh GL, Webster CR, Vucetich JA, Durocher JJ, Bump JK. Does persistent snowpack inhibit degradation of fecal stress indicators? CONSERVATION PHYSIOLOGY 2018; 6:coy071. [PMID: 30591839 PMCID: PMC6301288 DOI: 10.1093/conphys/coy071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 11/16/2018] [Accepted: 12/03/2018] [Indexed: 06/09/2023]
Abstract
Physiological stress in wildlife can be a useful indicator of a population's response to environmental factors. By using non-invasive endocrinological techniques, such as fecal sampling, potential confounding factors associated with the stress of capture can be avoided. A potential drawback of fecal sampling, however, is degradation of samples which may produce aberrant measurements of fecal glucocorticoid metabolites. In vertebrates, glucocorticoids, such as corticosterone, become elevated in response to stress. We sought to gauge the reliability of measurement of fecal glucocorticoid metabolites from white-tailed deer (Odocoileus virginianus) fecal samples exposed to a temperate winter with substantial snow cover and cold temperatures for up to 90 days, by repeatedly subsampling fecal samples every 10 days and performing a corticosterone enzyme-linked immunosorbent assay (ELISA). Measurements of fecal glucocorticoid metabolites at 10 days were consistent with initial measurements, after which (20 days) they became aberrant following a period of thawing. Consequently, glucocorticoid metabolite levels in feces appear to remain stable under ambient conditions if temperatures remain below freezing at least for 10 days. While it's possible that samples may remain useful beyond this time frame based on previous laboratory studies of samples stored in a freezer, further work is needed to determine how samples weather in situ under extreme cold (e.g. Arctic) or periods of partial thawing.
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Affiliation(s)
- Grace L Parikh
- School of Forest Resources and Environmental Science, Michigan Technological University, Houghton, MI, USA
| | - Christopher R Webster
- School of Forest Resources and Environmental Science, Michigan Technological University, Houghton, MI, USA
| | - John A Vucetich
- School of Forest Resources and Environmental Science, Michigan Technological University, Houghton, MI, USA
| | - John J Durocher
- Department of Biological Sciences, College of Sciences and Arts, Michigan Technological University, Houghton, MI, USA
| | - Joseph K Bump
- School of Forest Resources and Environmental Science, Michigan Technological University, Houghton, MI, USA
- Department of Fisheries, Wildlife and Conservation Biology, College of Food, Agricultural and Natural Resources Sciences, University of Minnesota, St. Paul, MN, USA
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10
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Webber JT, Henley MD, Pretorius Y, Somers MJ, Ganswindt A. Changes in African Elephant (Loxodonta africana) faecal steroid concentrations post-defaecation. ACTA ACUST UNITED AC 2018. [DOI: 10.4102/abc.v48i2.2312] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
Background: Faecal hormone metabolite measurement is a widely used tool for monitoring reproductive function and response to stressors in wildlife. Despite many advantages of this technique, the delay between defaecation, sample collection and processing may influence steroid concentrations, as faecal bacterial enzymes can alter steroid composition post-defaecation.Objectives: This study investigated changes in faecal glucocorticoid (fGCM), androgen (fAM) and progestagen (fPM) metabolite concentrations in faeces of a male and female African elephant (Loxodonta africana) post-defaecation and the influence of different faeces-drying regimes.Method: Subsamples of fresh faeces were frozen after being dried in direct sun or shade for 6, 20, 24, 48 and 72 h and 7 and 34 days. A subset of samples for each sex was immediately frozen as controls. Faecal hormone metabolite concentrations were determined using enzyme immunoassays established for fGCM, fAM and fPM monitoring in male and female African elephants.Results: Hormone metabolite concentrations of all three steroid classes were stable at first, but changed distinctively after 20 h post-defaecation, with fGCM concentrations decreasing over time and fPM and fAM concentrations steadily increasing. In freeze-dried faeces fGCM concentrations were significantly higher than respective concentrations in sun-dried material, which were in turn significantly higher than fGCM concentrations in shade-dried material. In contrast, fAM concentrations were significantly higher in sun- and shade-dried faeces compared to freeze-dried faeces. Higher fPM concentrations were also found in air-dried samples compared to lyophilised faeces, but the effect was only significant for sun-dried material.Conclusion: The revealed time restriction for collecting faecal material for hormone monitoring from elephants in the wild should be taken into account to assure reliable and comparable results. However, if logistics allow a timely collection, non-invasive hormone measurement remains a powerful and reliable approach to provide information about an elephant’s endocrine status.
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11
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Webster AB, Burroughs REJ, Laver P, Ganswindt A. Non-invasive assessment of adrenocortical activity as a measure of stress in leopards Panthera pardus. AFRICAN ZOOLOGY 2018. [DOI: 10.1080/15627020.2018.1467280] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Affiliation(s)
- Andrea B Webster
- Endocrine Research Laboratory, Department of Anatomy and Physiology, University of Pretoria, Pretoria, South Africa
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
| | - Richard EJ Burroughs
- Department of Production Animal Studies. Faculty of Veterinary Science, University of Pretoria, Pretoria, South Africa
- Centre of Veterinary Wildlife Studies, Faculty of Veterinary Science, University of Pretoria, Pretoria, South Africa
| | - Peter Laver
- Endocrine Research Laboratory, Department of Anatomy and Physiology, University of Pretoria, Pretoria, South Africa
- Animal Demography Unit, Department of Biological Sciences, University of Cape Town, Cape Town, South Africa
| | - André Ganswindt
- Endocrine Research Laboratory, Department of Anatomy and Physiology, University of Pretoria, Pretoria, South Africa
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
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12
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Yarnell K, Walker SL. Environmental Impact on Faecal Glucocorticoid Metabolite Concentrations in Grevy's Zebra (Equus grevyi). AFRICAN JOURNAL OF WILDLIFE RESEARCH 2017. [DOI: 10.3957/056.047.0138] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Affiliation(s)
- Kelly Yarnell
- School of Animal, Rural and Environmental Science, Nottingham Trent University, Southwell, Nottingham, United Kingdom, NG25 0QF
| | - Susan L. Walker
- North of England Zoological Society, Chester Zoo, Caughall Road, Upton-by-Chester, United Kingdom, CH2 1LH
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13
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Wong EP, Yon L, Purcell R, Walker SL, Othman N, Saaban S, Campos-Arceiz A. Concentrations of faecal glucocorticoid metabolites in Asian elephant's dung are stable for up to 8 h in a tropical environment. CONSERVATION PHYSIOLOGY 2016; 4:cow070. [PMID: 28066555 PMCID: PMC5196028 DOI: 10.1093/conphys/cow070] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Revised: 11/24/2016] [Accepted: 12/01/2016] [Indexed: 05/30/2023]
Abstract
The use of faecal glucocorticoid metabolites (fGCMs) has facilitated the development of non-invasive methods to study physiological conditions of endangered wildlife populations. One limitation is that fGCM concentrations are known to change over time and to vary according to different environmental conditions. The aim of this study was to perform a controlled dung decay experiment to understand the impact of time (since defecation) and two common environmental variables (exposure to water and direct sunlight) on fGCM concentrations of Asian elephants (Elephas maximus). Eighty dung piles from 10 Malaysian elephants were randomly exposed to a 2 × 2 combination of treatments (wet-shade, dry-shade, wet-sun and dry-sun) and repeatedly subsampled from the time of defecation through to 2 days post-defecation (n = 685 faecal subsamples). Overall, the mean concentration of fGCMs was stable in samples of up to 8 h old from defecation time, regardless of environmental treatment (water or direct sunlight); thereafter, the overall mean fGCM concentrations increased, peaking 1 day after defecation (31.8% higher than at defecation time), and subsequently decreased (reaching values 9.2% below defecation time on the second day). Overall, the treatment of sun exposure resulted in higher fGCM concentration compared with shade, whereas water exposure (compared with no water exposure) had no impact on fGCM concentrations. Hence, in field studies we recommend collecting dung samples <8 h old and recording shade conditions (e.g. sun vs. shade) as a covariate for the subsequent interpretation of fGCM measurements. This study has helped to identify the optimal window for sampling in which we can have a higher confidence in interpreting the results as being a genuine reflection of glucocorticoid status in the elephant.
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Affiliation(s)
- Ee Phin Wong
- School of Environmental and Geographical Sciences, Faculty of Science, The University of Nottingham Malaysia Campus, Jalan Broga, Semenyih 43500, Kajang, Selangor, Malaysia
- Mindset, Interdisciplinary Centre for Tropical Environmental Studies, The University of Nottingham Malaysia Campus, Jalan Broga, Semenyih 43500, Kajang, Selangor, Malaysia
| | - Lisa Yon
- School of Veterinary Medicine and Science, Faculty of Medical & Health Sciences, The University of Nottingham, Sutton Bonington, LeicestershireLE12 5RD, UK
| | | | | | - Nasharuddin Othman
- Department of Wildlife and National Parks Peninsular Malaysia, Km. 10, Jalan Cheras, 56100 Kuala Lumpur, Malaysia
| | - Salman Saaban
- Department of Wildlife and National Parks Peninsular Malaysia, Km. 10, Jalan Cheras, 56100 Kuala Lumpur, Malaysia
| | - Ahimsa Campos-Arceiz
- School of Environmental and Geographical Sciences, Faculty of Science, The University of Nottingham Malaysia Campus, Jalan Broga, Semenyih 43500, Kajang, Selangor, Malaysia
- Mindset, Interdisciplinary Centre for Tropical Environmental Studies, The University of Nottingham Malaysia Campus, Jalan Broga, Semenyih 43500, Kajang, Selangor, Malaysia
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14
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Abstract
Over several decades, animal welfare has grown into its own free-standing field of scientific study, from its early beginnings in laboratory animal research to eventually include exhibited animals and farm animals. While it has always been present to some degree, consideration of animal welfare for free-ranging animals has lagged behind, developing as a field of study in the last 20 yr or so. Part of that increase was that animal welfare legislation was finally applied to studies being done on free-ranging animals. But it is the appreciation by the biologists and veterinarians working on wild animals, in which the quality of their results is largely controlled by the quality of the animals they use in their studies, which has resulted in increased attention to the well-being or welfare of the animals that they use. Other important influences driving the recognition of wildlife welfare have been changes in the public's expectations of how wild animals are dealt with, a shift in focus of wildlife professionals from managing animals that can be hunted or angled to include nongame species, the decrease in participation in hunting and fishing by members of the public, and the entry of large numbers of women into fish and wildlife agencies and departments and into veterinary medicine. Technical improvements have allowed the safe capture and handling of large or dangerous animals as immobilization drugs and equipment have been developed. The increasing use of sedating drugs allows for handling of animals with reduced stress and other impacts. A number of topics, such as toe-clipping, branding, defining which taxa can or cannot feel pain, catch-and-release fishing, and more, remain controversial within wildlife science. How we treat the wild animals that we deal with defines who we are as wildlife professionals, and animal welfare concerns and techniques for free-ranging animals will continue to develop and evolve.
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15
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Non-invasive genetic sampling reveals diet shifts, but little difference in endoparasite richness and faecal glucocorticoids, in Belizean felids inside and outside protected areas. JOURNAL OF TROPICAL ECOLOGY 2016. [DOI: 10.1017/s0266467416000213] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Abstract:Many Neotropical felids are threatened with extinction due to direct effects of habitat destruction and/or human persecution. However, indirect and synergistic effects of human-felid conflict remain under-studied and potentially include increased stress and diet shifts that may negatively impact felid health. We hypothesized that faecal glucocorticoid metabolites (FGM) and endoparasite species richness (ESR) would be higher, and diet would shift, for felids outside protected areas where conflict occurs. In north-western Belize, a scat-detector dog located 336 faecal samples, identified to species and individual using DNA analyses. DNA amplification success was substantially higher within protected areas than outside. We detected jaguar, puma, ocelot, jaguarundi and domestic cat. FGMs were higher in puma and jaguarundi than in other felids, while ESR was similar across felids with domestic cats exhibiting the highest number of genera. Diet partitioning occurred among felids, but domestic cats may compete with ocelot and jaguarundi for small prey. Outside of protected areas, large cats shifted their diet to smaller prey and livestock remains were not found. Contrary to our hypotheses, FGM and ESR did not differ inside versus outside protected areas, but sample sizes were low in human-modified areas. We provide a baseline on wild felid adrenal activity, endoparasites and diet and suggest improvements to increase sample sizes outside protected areas. Our research provides a template for expanding non-invasive sampling approaches more widely across the range of Neotropical felids.
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16
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Parnell T, Narayan EJ, Nicolson V, Martin-Vegue P, Mucci A, Hero JM. Maximizing the reliability of non-invasive endocrine sampling in the tiger (Panthera tigris): environmental decay and intra-sample variation in faecal glucocorticoid metabolites. CONSERVATION PHYSIOLOGY 2015; 3:cov053. [PMID: 27293737 PMCID: PMC4778480 DOI: 10.1093/conphys/cov053] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Revised: 10/21/2015] [Accepted: 10/27/2015] [Indexed: 06/06/2023]
Abstract
Evaluation of physiological stress in the tiger (Panthera tigris) using faecal cortisol metabolite (FCM) enzyme immunoassays (EIAs) provides a powerful conservation physiology tool for the species. However, it is important to validate non-invasive endocrine sampling techniques in field conditions to ensure that the method provides a reliable parameter of physiological stress in the species. This is because endocrine measurements are highly species specific and FCM concentrations can be influenced by environmental factors. Here, we studied the impact of the decay rate of FCMs and intra-sample variation of FCMs using a previously validated EIA. To determine the decay rate of FCMs, we measured FCMs in freshly deposited tiger faeces (n = 8 tigers and 48 scats) that were randomly exposed to the natural environment (dry conditions with no rainfall) for up to 192 h. To determine intra-sample variation in FCMs, we used 10 scats from 10 tigers, divided each sample into four sections and each section into four sub-sections and measured FCMs in each section and sub-section. The results of this decay-rate experiment showed that FCMs in tiger faeces began to decay after 48 h exposure to the environmental conditions available. Thus, FCMs within freshly deposited tiger faeces are influenced by available environmental conditions. Changes in weather conditions (e.g. increased rainfall and humidity) could influence the stability of FCMs. The results of the intra-sample variation study showed that inter-variation among scats accounted for 52% of the variations in FCMs, while intra-sample variation between sections (32%) was greater than the sub-sample variation (16%). Intra-sample variation can be reduced by homogenizing the entire lyophilized faecal sample prior to the EIA. In conclusion, careful evaluation of decay rate and complete homogenization of faeces prior to EIA analysis will increase the reliability of FCMs as a non-invasive index of physiological stress in the tiger.
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Affiliation(s)
- Tempe Parnell
- Environmental Futures Research Institute, School of Environment, Griffith University, Gold Coast campus, Queensland 4222, Australia
| | - Edward J. Narayan
- Environmental Futures Research Institute, School of Environment, Griffith University, Gold Coast campus, Queensland 4222, Australia
- Graham Centre for Agricultural Innovation & School of Animal and Veterinary Sciences, Faculty of Science, Charles Sturt University, Wagga Wagga, NSW 2678, Australia
| | - Vere Nicolson
- Life Sciences, Dreamworld, Parkway Coomera, Queensland 4209, Australia
| | | | - Al Mucci
- Life Sciences, Dreamworld, Parkway Coomera, Queensland 4209, Australia
| | - Jean-Marc Hero
- Environmental Futures Research Institute, School of Environment, Griffith University, Gold Coast campus, Queensland 4222, Australia
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