Social vocal communication in captive Pacific walruses Odobenus rosmarus divergens

Abstract: Walrus are highly gregarious pinnipeds that can form herds of several hundreds or thousands of individuals when hauling out on ice or on land. They produce vocalisations in almost all social interactions, from aggressive vocalisations, contact calls involved in mother–calf bond to adult–adult communication to stereotyped courtship display during the mating season. The knowledge on walrus’ vocal behaviour and its perceptual abilities is limited due to the extreme difficulty of studying these animals in their natural environment. In the present study, we reported the results of a pilot experimental work on group/social vocal communication in captive Pacific Walruses (Odobenus rosmarus divergens). By analysing the main vocalisations produced by females and males during social interactions, we found some differences in their call characteristics compared to the Atlantic subspecies. In a second step, we experimentally demonstrated the abilities of females and mature males to discriminate between vocalizations of individuals from their own group and those of unknown individuals. In spite of the low sample size of animals, these findings on captive walruses improved knowledge of the cognitive abilities of this endemic Arctic species. [Copyright &y& Elsevier]