Spontaneous Yawning and its Potential Functions in South American Sea Lions (Otaria flavescens).

ABSTRACT: Spontaneous yawning is a widespread behaviour in vertebrates. However, data on marine mammals are scarce. In this study, we tested some hypotheses on the functions of yawning in a captive group of South American sea lions (Otaria flavescens). According to the Dimorphism Hypothesis, species showing low levels of sexual dimorphism in canine size do not show sex differences in yawning distribution; this was supported by our findings, since yawning did not differ between the sexes. Yawning was more frequently performed during resting/sleeping contexts, thus supporting the Drowsiness Hypothesis. Yawning and self-scratching are considered reliable indicators of short-term anxiety in sea lions, since they immediately increased after conflicts both in aggressors and victims (Social Distress Hypoth

SUBMITTER: Palagi E 

PROVIDER: S-EPMC6872524 | biostudies-literature | 2019 Nov

REPOSITORIES: biostudies-literature