Face markings in Northern chamois: cues of dominance?

Abstract

AbstractBlack and white face markings in Artiodactyls are thought to be broadly associated with intraspecific communication. Evidence-based studies on the fine-scale mechanisms of signaling, however, are scant. The occurrence of black and white face markings is one of the most distinctive features of the Northern chamois Rupicapra rupicapra. Although their function is unknown, they might possibly signal fighting abilities: if so, the intensity of face color contrast should positively correlate with traits involved in aggressive contests, i.e. body mass and horn size. We collected data on face marking ‘blackness’ as a proxy of color contrast, dressed body mass and horn length on 103 chamois of either sex harvested during the hunting season of 2019 in the central Italian Alps. To investigate the relationship between color contrast and sex-specific body mass and horn length, we fitted an ordinal multilevel regression model in a Bayesian framework. Contrast score positively associated with increasing body mass in both sexes, but this relationship was much stronger in females than in males. Contrast score positively related with horn length in males but not in females. Our results offer some first insights into the potential correlates of chamois facial mask, suggesting that face markings might provide age-specific cues of mass-based dominance in females, while their role in males appears more uncertain. Behavioral studies on marked or hunted individuals in different environmental settings are necessary to confirm these findings, and provide further understandings of face color patterns in chamois.