Abstract: A substantial amount of research has been carried out on recognition behaviour in natural populations of pinnipeds. This work includes detailed anecdotal and quantitative descriptions in addition to in situ experimental tests of recognition. The goals of this review are to summarize this research, and by doing so, to point out apparent patterns of social recognition among the pinnipeds, as well as important gaps in our knowledge. Following an introduction of the topic, the review is divided into three sections: (1) descriptive evidence, (2) experimental evidence, and (3) patterns of recognition in pinnipeds resulting from phylogenetic, ecological and life history constraints. The descriptive evidence mostly pertains to recognition between mother and offspring and includes vocal stereotypy, the use of other sensory modalities, and cases of adoption and allo-suckling. Further descriptive data include recognition among territorial males and between species. The experimental evidence is also weighted heavily towards tests of mother- offspring recognition. Recognition between pinniped mothers and pups, in at least one direction (i.e., mother recognizes pup or pup recognizes mother), has been experimentally demonstrated in seven pinniped species (4 otariids and 3 phocids), but is not the rule. Recent experiments have also been completed on recognition ontogeny and salient cues, as well as demonstrating long-term recognition. Such results provide the basis for complex social interactions among individuals. As with descriptive evidence, methodologies are an important aspect of these data. Finally, all the pinniped recognition data are synthesized with respect to the variability of intra- and interspecific pressures affecting the evolution of recognition behaviour.

Key Words: RECOGNITION; SOCIAL BEHAVIOUR; PINNIPED; SEAL; SEA LION; WALRUS; VOCALIZATION; SIGNALLING; MAMMAL; VERTEBRATE; ALLO-SUCKLING; OLFACTION.

Document Type: Research article