Changes in African Elephant (Loxodonta africana) faecal steroid concentrations post-defaecation
| Autor: | Michelle Henley, Andre Ganswindt, Yolanda Pretorius, Judith T. Webber, Michael J. Somers |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
0106 biological sciences
0301 basic medicine lcsh:QH1-199.5 medicine.drug_class Metabolite non-invasive hormone monitoring Plant Science lcsh:General. Including nature conservation geographical distribution Biology 010603 evolutionary biology 01 natural sciences African elephant 03 medical and health sciences chemistry.chemical_compound Animal science biology.animal medicine bacterial degradation progestagens Testosterone Feces Ecology Evolution Behavior and Systematics glucocorticoids androgens Androgen 030104 developmental biology chemistry Sample collection Hormone Measurement Hormone |
| Zdroj: | Bothalia-African Biodiversity & Conservation, Volume: 48, Issue: 2, Pages: 1-8, Published: 2018 Bothalia: African Biodiversity & Conservation, Vol 48, Iss 2, Pp e1-e8 (2018) |
| ISSN: | 2311-9284 0006-8241 |
| Popis: | 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. |
| Databáze: | OpenAIRE |
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