Sex and Individual Specificity in Behavioral Responses to Chemical Communication and Urinary Volatile Components in...

The forest musk deer (Moschus berezovskii) is an endangered species endemic to China. Like many solitary and highly territorial herbivores, forest musk deer rely on chemical signals to convey complex information. However, the chemical composition and functional roles of these signals remain poorly understood. In this study, behavioral assays showed that forest musk deer (8 males and 26 females) exhibited stronger responses to urine than to feces. To characterize the chemical basis of this response, urine samples from five males and five females were analyzed using headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC-MS), leading to the identification of 83 volatile compounds. Discriminant analyses revealed significant differences in urinary volatile profiles according to both sex and among individuals, with classification accuracies of 100% for sex and 96.7% for individual differentiation. Orthogonal partial least squares discriminant analysis (OPLS-DA) further identified 33 and 17 compounds that potentially convey sex-specific and individual-specific information, respectively, with only nine compounds implicated in both functions. These results suggest that forest musk deer employ a multi-layered coding system in chemical communication, in which distinct chemical compounds encode different types of biological information. Overall, this study provides a framework for understanding chemical signaling in captive forest musk deer and offers insights relevant to the conservation and sustainable management of musk deer populations.