Identifying personality traits and their potential application to the management of captive forest musk deer (Moschus berezovskii)

Since the 1950s musk deer (Moschidae) are kept in captivity for the production of musk, a glandular secretion used in Chinese traditional medicine and as an ingredient in cosmetics. Most recently, forest musk deer (Moschus berezovskii) raised in captivity were reintroduced to augment depleted wild populations. The most prominent behavioral and social characteristics of musk deer are anxiety, a timid, solitary lifestyle and territoriality, making musk deer difficult to breed. Individual differences in the personality of captive male musk deer could allow breeders to sort bold individuals that are suitable for commercial farming from those with a shy and more timid personality suitable for reintroduction. We attempted to identify what behavioral variables and what novel stimulus tests are the most effective to characterize whether an individual is bold or shy. To measure boldness in 31 adult males, we used a two-step approach: i) using a Principal Component Analysis to identify reference behaviors that are indicative of either a shy or a bold personality, and ii) to establish individual boldness scores based on those reference behaviors and compare them between four novel stimuli. We obtained two 'bold PCs' with high axis loadings from behaviors that are typical for curiosity, territorial marking or that represent the ordinary daily activity of a ruminant, as well as three 'shy PCs' that received high axis loadings from behaviors that are typical for anti-predator responses, intimidation or displacement behavior. Although all tested stimuli were verified suitable, the unfamiliar human being was the strongest stimulus to test boldness, followed by leopard feces, a beach ball and a leopard dummy. Using cluster analysis, nearly three quarter of tested individuals were identified as shy, while only one quarter was classified as bold. Previous studies on poultry and domestic ungulates, demonstrated that through continued selective breeding for boldness, the overall personality in the population is driven towards a calm temperament in the majority of the individuals. This might be beneficial for musk production but will have adverse effects on successful reintroductions due to reduced individual fitness and domestication effects.