Gender, season and management affect fecal glucocorticoid metabolite concentrations in captive goral (Naemorhedus griseus) in Thailand.

Chinese goral (Naemorhedus griseus) are a threatened species in Thailand and the focus of captive breeding for possible reintroduction. However, little is known of their biology or what factors in the captive environment affect welfare. Our objective was to determine the impact of gender, season, and management on goral adrenal activity. We hypothesized that differences in fecal glucocorticoid concentrations would be related to animal density. Fecal samples were collected 3 days/week for 1 year from 63 individuals (n = 32 males, 31 females) at two facilities that house the majority of goral in Thailand: Omkoi Wildlife Sanctuary (Omkoi), an off-exhibit breeding center that houses goral in individual pens (16 pens; n = 8 males, 8 females) and in small family groups (8 pens; n = 8 males, 8 females); and the Chiang Mai Night Safari (NS), a zoo that maintains 31 goral (n = 17 males, 14 females) in one large pen. Glucocorticoid metabolite concentrations were higher in male than female goral at Omkoi throughout the year, and there was a seasonal effect on adrenal activity (p<0.05). Goral at Omkoi and NS were used to test the effect of animal density on fecal glucocorticoid excretion of goral housed in similar-sized enclosures. Overall, the highest levels were found at NS (n = 31 adults/pen; 27 m2 per animal) compared to Omkoi (n = 2 adults/pen; 400 m2 per animal) (p<0.05). Overall findings support our hypothesis that animal density and aspects of the captive environment impact adrenal steroid activity in captive goral. In addition, gender and season also had significant effects on glucocorticoid metabolite production. Potential stressors pertaining to the welfare of this species were identified, which will guide future efforts to improve management and create self-sustaining and healthy populations of this threatened species

Facility effect on mean (± SEM) fecal glucocorticoid metabolite concentrations (ng/g) in goral housed in large (30 m×40 m, area 400 m² per animal) enclosures at Omkoi Wildlife Sanctuary, and one large enclosure (35 m×24 m, area 27 m² per animal) at Night Safari across the three seasons in Thailand.

a,b<p>Values differ among enclosure sizes, different letters indicate differences (<i>p</i><0.05).</p>1,2<p>Values differ among seasons, different numbers indicate differences within the same enclosure sizes (<i>p</i><0.05).</p

Seasonal pattern of fecal glucocorticoids.

<p>Longitudinal mean (± SEM) fecal glucocorticoid metabolite concentrations for male and female gorals were determined by a cortisol EIA. Fecal samples were collected from February 2010 through February 2011, representing the summer (February 16 – May 15), rainy (May 16 – October 15) and winter (October 16 – February 15) seasons.</p

Seasonal mean (± SEM) average daily temperature and rainfall at two captive goral facilities in Thailand.

a,b<p>Values differ among facilities, different letters indicate differences (<i>p</i><0.05).</p>1,2<p>Value differ among seasons, different numbers indicate differences within the same facility (<i>p</i><0.05).</p

Mean (± SEM) fecal glucocorticoid metabolite concentrations (ng/g) between male and female goral at Omkoi Wildlife Sanctuary across the three seasons in Thailand.

a,b<p>Values differ between male and female gorals, different letters indicate differences (<i>p</i><0.05).</p>1,2<p>Values differ among seasons, different numbers indicate differences within the same gender</p><p>(<i>p</i><0.05).</p

Effect of housing on glucocorticoid production.

<p>Longitudinal mean (± SEM) fecal glucocorticoid metabolite concentrations for goral housed at two facilities in Thailand, determined by a cortisol EIA. Fecal samples were collected from February 2010 through February 2011, representing the summer (February 16 – May 15), rainy (May 16 – October 15) and winter (October 16 – February 15) seasons.</p

Chromatographic analysis of glucocorticoid metabolite immunoreactivity.

<p>Immunoreactivity of glucocorticoid metabolites in fecal extracts of goral was determined by reverse-phase HPLC analysis. Glucocorticoid concentration in each fraction was determined using a cortisol EIA. Elution of ³H-cortisol and ³H-corticosterone reference tracers in HPLC fractions of extracted fecal samples are indicated by the arrows.</p

Goral pens.

<p>Examples of goral housing conditions: (a) as individuals in small pens (6 m×9 m) at Omkoi Wildlife Sanctuary; (b) in family groups in large pens (30 m×40 m) at Omkoi Wildlife Sanctuary; and (c) all animals together in a large (35 m×24 m) at Night Safari.</p