CONICET | Buscador de Institutos y Recursos Humanos

Three Heaviside?s dolphins (Cephalorhynchus heavisidii) were fitted with satellite depth recorders on the west coast of South Africa in February - April 1997 and monitored for 51-130 days. In total, 345 locations were received from all three animals, but only 27 from one male. Using α-Local Convex Hull and Minimum Convex Polygon methods, the home ranges for the remaining male and female were estimated at 1,520 ? 2,347 km2 and 672 ? 1,027 km2,respectively, with corresponding core areas (50% of locations) of 134 ? 123 km2 and 71 - 230 km2 . The female?s home range was the smallest yet described for this species, and it was resighted three years later within 13 km of the tagging site. Binned dive data were received at six-hourly intervals. From comparison of maximum dive depth and time at depth data, we concluded that dives < 4 m deep were associated with surfacing bouts. Dives to below 4 m occurred throughout 24 h but were shallower during the day and deepest at either dusk or night. This pattern was consistent with earlier descriptions of offshore movement during the day and may be related to the diel vertical migration of its principal prey, shallow-water hake (Merluccius capensis).