MSc Thesis Abstract:

The matrilineal society of the sperm whale functions to provide protection for calves at the surface while mothers make deep dives for food. Sperm whale females do have a system of babysitting, but details are unknown. This study aimed to elucidate the behaviour involved in sperm whale allocare, in particular who babysits whose calf; whether or not suckling from a non-parent occurs; and to describe sperm whale suckling beahviour. Using photo-identification and behavioural calf-follows, I examined patterns of adult-infant interaction for 23 sperm whale calves in the Sargasso and Caribbean Seas. In the Caribbean, a preferred babysitter provided most of the allocare but did not nurse the calf; whereas in the Sargasso, multiple nursing escorts provided care for the young. Furthermore, I found that peduncle dives by calvs under adults, surface behaviour previously thought to indicate suckling, are latterally asymmetrical and may not always indicate milk aquisition through the mouth.