Effects of natural environmental conditions on faecal glucocorticoid metabolite concentrations in jaguars (Panthera onca) in Belize

Abstract

We performed immunoassay and environmental validations to assess the effects of natural environmental exposure of jaguar faeces on glucocorticoid metabolites. Glucocorticoid concentrations were stable for 5 days with the corticosterone RIA. Scat aging by morphology was unreliable. Environmental validation is needed to determine field sample collection protocols for elusive species.

Concentrations of faecal glucocorticoid metabolites in Asian elephant's dung are stable for up to 8 h in a tropical environment

“…It is not clear why water exposure resulted in an elevation in fGCM concentrations in some studies (Washburn and Millspaugh, 2002; Mesa-Cruz et al ., 2014) but not in the present study. Some possible reasons are as follows: (i) water might cause changes in metabolite immunoactivity that can be picked up by some enzyme immunoassays or radioimmunoassays but not by others (Mesa-Cruz et al ., 2014); (ii) there could be differences in faecal forms (e.g.…”

“…Some possible reasons are as follows: (i) water might cause changes in metabolite immunoactivity that can be picked up by some enzyme immunoassays or radioimmunoassays but not by others (Mesa-Cruz et al ., 2014); (ii) there could be differences in faecal forms (e.g. elephant dung is voluminous and highly fibrous, bird faeces are in the form of powder, and deer faeces are small dense pellets) or other unmeasured variables that might be influencing the interaction between water and the metabolism of the glucocorticoids present in the faeces; (iii) the high humidity in the tropical environment might also affect samples not treated with water and thus confound the effect of the water treatment; and (iv) it is possible that the amount of water used in our experiment was insufficient to affect fGCM concentrations.…”

“…Moreover, exposure to different temperatures and humidity treatments had complex effects on the fGCM concentration in faeces of white-tailed deer ( Odocoileus virginianus ; Washburn and Millspaugh, 2002), wild bears ( Ursus spp. ; Stetz et al ., 2013) and jaguars ( Panthera onca ; Mesa-Cruz et al ., 2014). These results highlight the importance of assessing fGCM stability in field conditions in studies using fGCM to monitor wildlife populations.…”

Environmental Impact on Faecal Glucocorticoid Metabolite Concentrations in Grevy's Zebra (Equus grevyi)

“…A study by Washburn & Millspaugh (2002) found that white-tailed deer (Odocoileus virginianus) faeces that had been exposed to rainfall had artificially inflated FGM levels. By contrast, jaguar (Panthera onca) faecal samples exposed to sunlight did not show a change in FGM concentrations (Mesa-Cruz et al, 2014). However, wet conditions altered metabolite levels after five days of exposure (Mesa-Cruz et al, 2014).…”

“…By contrast, jaguar (Panthera onca) faecal samples exposed to sunlight did not show a change in FGM concentrations (Mesa-Cruz et al, 2014). However, wet conditions altered metabolite levels after five days of exposure (Mesa-Cruz et al, 2014). Consequently, the authors suggested running sample transects every three to four days in both wet and dry seasons (Mesa-Cruz et al, 2014).…”