Relationship between Sociability and Faecal Cortisol in Captive Alpine Musk Deer Moschus chrysogaster Hodgson, 1839 (Mammalia: Moschidae)

Sociability indicates the variances of affinity and solitary among animals and it is strongly correlated with cortisol levels. This study was conducted in 2020, from September 16th to October 15th, at the Zhuanglang Musk Deer Farm in Gansu Province of China. We recorded behaviours of 41 captive Alpine musk deer (Moschus chrysogaster) (in 12 enclosures) using the integrated methods of focal sampling and all occurrence recording for sociability analysis, while non-invasive sampling methods and radioimmunoassay were used to collect and measure faecal cortisol level. The relationship between the sociability of captive Alpine musk deer and faecal cortisol hormone was analysed. The results showed that the sociability of captive Alpine musk deer was 14.754% (± 3.026%) (n=41). Individuals in high-density enclosures (19.090% ± 4.497%, n=26) were significantly more sociable as compared to those in low-density enclosures (7.979% ± 2.640%, n=15; P=0.011). The cortisol level of Alpine musk deer was 109.215 (± 5.349) ng/g (n=41). The cortisol level of female individuals (120.419 ± 11.103 ng/g, n=14) was significantly higher than that of male individuals (103.406 ± 5.575 ng/g, n=27; P=0.008). The male musk deer in high sociability (44.114% ± 9.364%, n=8) had lower faecal cortisol levels (102.415 ± 14.885 ng/g, n=8) than those in low sociability (5.518% ± 1.369%, n=19) (103.823 ± 5.243 ng/g, n=19), however these differences were not significant (P=0.911). The female musk deer in high sociability (20.556% ± 2.174%, n=3) had significantly lower (P=0.035) faecal cortisol levels (77.018 ± 17.036 ng/g, n=3) than those in low sociability (7.773% ± 1.595%, n=11) (132.256 ± 11.079 ng/g, n=11), which could be related to maternal care and weaning period. It is suggested that the enclosing density should be increased to improve captive Alpine musk deer’s (especially female musk deer) sociability in the domestication of musk deer.