We studied maternal care in Steller sea lions (Eumetopias jubatus) at a small rookery in the northern Gulf of Alaska over the course of 4 summers, 2001–2004 and 3 autumn seasons, 2002–2004, using remotely operated video cameras. Perinatal periods were long (≥10.0 days); although varied between years. Timing of parturition was earlier and perinatal periods longer for multiparous females compared to females considered to be primiparous. Summer foraging trip durations were short (X̄ = 16.5 h), increased during August, then did not change significantly over the course of the autumn (X̄ = 55.7 h). Individual lactating females spent a greater proportion of their time on shore during the summer and a greater proportion of their time at sea during the autumn. The amount of time that females nursed their pups also increased significantly from the summer to autumn. Long perinatal periods and short foraging trips during summer indicate that sea lions are likely finding sufficient food nearby. Our data also suggest that Steller sea lions reach an upper plateau in duration of foraging cycles as early as mid-August and large increases above that plateau may indicate difficulty finding sufficient food during the winter months.
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