Non-vocal Communication in Otariids and Odobenids: The Involvement of Visual and Olfactory Cues in Their Social Lives

While vocal communication is prominent in pinnipeds, visual and olfactory cues are also important in social interactions, yet they have been poorly investigated. Behavioral observations of mother-pup and male-male interactions suggest the involvement of visual and olfactory cues to facilitate mother-pup reunion and to advertise the presence of competitors or territory ownership. Experimental studies have shown that mothers can recognize their pups on the only basis of olfactory cues, and visual cues such as size and fur color pattern are used by females to sort pups in different age-classes. Otariid males exhibit specific body postures to threaten their competitors and walrus males display elaborate visual courtship display during the breeding season. During the breeding season, mature males develop a specific odor advertising their presence and reproductive status, and experiments show they can discriminate this musky male scent. This chapter relates the importance of olfactory and visual cues in their social interactions, and outlines future investigations needed to better understand the role of these under explored sensory modalities in communication in marine mammals and mammals in general.