Stereotyped calling patterns of a male Weddell seal

Abstract

Underwater calling behavior between breathing bouts of a (presumed) single adult male Weddell seal (Leptonychotes weddellii) was examined at Davis Station, Antarctica. Underwater calls and in-air breathing sounds were recorded on 1 and 8 December. Thirty-six postdive and 37 presurfacing sets of calls were analyzed. Dives were 461±259 s (mean ± S.D.). The seal called every 22.7±21.7 s. The first two calls after diving were at 15.6±9.3 and 33.3±9.7 s. The last two calls occurred at 38.8±32.0 and 22.7±20.1 s before surfacing. The first call after a dive was usually (29/36) a low-frequency growl. One of three patterns of 3–5 call-type sequences was made following 26 of 36 dives. A common four-call sequence was also recorded earlier in the breeding season at this location and was absent at four other distant breeding sites. The timing and call-type sequences of underwater vocalizations after a dive were highly stereotyped, while those before surfacing were not. Territorial males may call throughout each dive and use stereotyped call patterns to identify themselves. [Work supported by Australian Antarctic Division and NSERC.]