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Khonmee J.,Chiang Mai University | Vorawattanatham N.,Conservation and Research Section | Pinyopummin A.,Kasetsart University | Thitaram C.,Chiang Mai University | And 3 more authors.
Conservation Physiology | Year: 2016

There is little information on the endocrinology of fishing cats (Prionailurus viverinus), an endangered species in Southeast Asia, especially that pertaining to adrenal function. This study characterized faecal glucocorticoid metabolites in female fishing cats housed at Chiang Mai Night Safari to investigate seasonal and age relationships in hormone patterns. Faecal samples were collected 3 days/week for 1 year from seven females ranging in age from 4.5 to 9.6 years. A corticosterone enzyme immunoassay was validated for fishing cats by showing increases (~60%) in faecal glucocorticoid immunoactivity above pre-treatment baseline levels within 1-2 days after an adrenocorticotrophic hormone injection. Faecal glucocorticoid metabolite concentrations were not related to age (P > 0.05), but there was a seasonal effect, with concentrations being higher (P < 0.05) during the winter (1.54 ± 0.04 μg/g) and rainy season (1.43 ± 0.04 μg/g) compared with the summer (1.22 ± 0.05 μg/g). Significant relationships were found between faecal glucocorticoids and rainfall (positive) and day length (negative), but not a temperature-humidity index. This is the first study to assess adrenal steroidogenic activity in female fishing cats, and we found that glucocorticoid metabolite production was influenced by seasonal factors, but not by age. We conclude that weather patterns should be taken into consideration in future studies of glucocorticoid activity in this endangered species, especially those studies aimed at improving captive management to create self-sustaining and healthy populations. © The Author 2016.


PubMed | Chiang Mai University, Smithsonian Conservation Biology Institute, Kasetsart University and Conservation and Research Section
Type: Journal Article | Journal: Conservation physiology | Year: 2016

There is little information on the endocrinology of fishing cats (Prionailurus viverinus), an endangered species in Southeast Asia, especially that pertaining to adrenal function. This study characterized faecal glucocorticoid metabolites in female fishing cats housed at Chiang Mai Night Safari to investigate seasonal and age relationships in hormone patterns. Faecal samples were collected 3days/week for 1year from seven females ranging in age from 4.5 to 9.6years. A corticosterone enzyme immunoassay was validated for fishing cats by showing increases (60%) in faecal glucocorticoid immunoactivity above pre-treatment baseline levels within 1-2days after an adrenocorticotrophic hormone injection. Faecal glucocorticoid metabolite concentrations were not related to age (P>0.05), but there was a seasonal effect, with concentrations being higher (P<0.05) during the winter (1.540.04g/g) and rainy season (1.430.04g/g) compared with the summer (1.220.05g/g). Significant relationships were found between faecal glucocorticoids and rainfall (positive) and day length (negative), but not a temperature-humidity index. This is the first study to assess adrenal steroidogenic activity in female fishing cats, and we found that glucocorticoid metabolite production was influenced by seasonal factors, but not by age. We conclude that weather patterns should be taken into consideration in future studies of glucocorticoid activity in this endangered species, especially those studies aimed at improving captive management to create self-sustaining and healthy populations.


Chuang Y.-L.,National Chung Hsing University | Yu S.-F.,National Chung Hsing University | Yu S.-F.,Conservation and Research Section | Lin H.-J.,National Chung Hsing University
Zoological Studies | Year: 2014

Background: The classification of functional feeding groups of aquatic insects is often misleading in tropical/subtropical streams because their feeding habits are assumed to be the same as their temperate counterparts according to the mouthpart structure and foraging behavior. This study aimed to examine the diets and preferences of mayfly grazers (Baetis spp. and Rhithrogena ampla) in a subtropical mountain stream in the dry and wet seasons. Results: In the stream, epilithic algal communities on insect-excluded bricks (as a grazer-excluded control) were dominated by small adnate diatoms, most likely due to the high current velocity. Both grazers preferred understory and small adnate diatoms, Achnanthes spp. and Achnanthidium pyrenaicum, in both seasons. However, the stalked diatoms Gomphonema spp. were preferred only by Baetis, but not by Rhithrogena, in the dry season when the current velocity became relatively slower. The results of pairwise tests further showed that the algal compositions on the insect-excluded bricks coincided with the diets of both grazers in the wet season but were distinct from those on the bricks in the dry season. Seasonal variations in the algal compositions of the diets of Rhithrogena and on the insect-excluded bricks were apparent, but not in the diets of Baetis. Conclusions: The algal physiognomy was most likely attributed to the impact of the high current velocity in the stream. Our results suggest that the diet preference by mayfly grazers in the stream is potentially influenced by algal availability. © 2014 Chuang et al.

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