Underwater Vocalization by Sea Lions: Social and Mirror Stimuli

Abstract
Underwater vocal response of three sea lions (Zalophus californianus) increased under conditions of social interaction. When confronted by their mirror images, two animals increased their number of vocalizations, which included "whinny" sounds, barks, buzzing, and varying patterns of click trains. Click vocalizations showed habituation and recovery when the animals were in the presence of the mirror stimulus.