The evolution of anterior coloration in carnivorans

Abstract

Some carnivorans have striking patches of fur on their faces (spots, bands, eye masks) and blazes on their chests that are primarily visible from a frontal view. We tested five hypotheses to explain the evolution of the complexity and contrast of these color patches. These were: signals of species identity to avoid hybridization, communication between conspecifics, signals used to warn of defensive anal secretions, signals of belligerence or pugnacity, and camouflage-related coloration used to break up the outline and facial features of the predator when approaching prey. Using phylogenetically controlled multifactorial analyses in six different families of carnivorans, examined separately, our analyses uncovered significant positive associations between measures of color pattern complexity and sociality across herpestid faces and canid chests, suggesting use in social communication. Mustelid facial color complexity was associated with ability to direct anal secretions accurately at predators, and facial markings were significantly or marginally associated with pugnacity in mustelids, viverrids, and herpestids. Facial complexity of viverrid and herpestid species was significantly or marginally related to a mammal-based diet. In ursids, facial contrast appeared less variable in species living in greater sympatry with other bears. Facial and chest coloration in Carnivora appears to have evolved under different selection pressures in different families.

Significance statement

The reasons that many carnivorans have colorful and memorable faces and chests are not yet understood. Here, we pit five different hypotheses against each other: species recognition, advertising either toxic anal defenses or pugnacity, recognizing group members, and trying to remain concealed when approaching mammalian prey. We find that measures of facial and chest complexity and contrast have evolved for different reasons depending on the carnivoran family. Anterior coloration appears to be involved with social communication in herpestids and canids; facial coloration is associated noxious secretions in mustelids, with pugnacity in mustelids, viverrids and herpestids; with reliance on a mammal-based diet in viverrids and herpestids; and with avoiding hybridization in bear species. There is no overriding evolutionary explanation for varied facial and chest pelage coloration across carnivorans.