Behaviour of lactating stellar sea lions (eumetopias jubatus) during breeding season : a comparison between a declining and stable population in Alaska ...

• Main Author: Milette, Linda Leontine
• Format: Text
• Language: English
• Published: University of British Columbia 2009
• Subjects: Alaska; Sugarloaf Island
• Online Access: https://dx.doi.org/10.14288/1.0074835; https://doi.library.ubc.ca/10.14288/1.0074835

Female attendance patterns and activity budgets of Alaskan Steller sea lions (Eumetopias jubatus) were compared at two sites using scan sampling over two summer breeding seasons in 1994 and 1995 at Sugarloaf Island (a declining population) and Lowrie Island (a stable population). The goal was to document female behaviour and to determine whether there were behavioural differences between the two sites that were consistent with the hypothesis that Steller sea lions in the area of population decline were foodlimited. The perinatal period (time from birth of pup to the mother's first feeding trip) averaged 10.1 days in the area of population decline compared to 8.0 days in the stable area, counter to initial predictions. The first shore visit following the perinatal period was significantly longer in the area of population decline compared to the stable population. Females from both populations exhibited a diel haul out pattern where the majority of returns and departures to and from the rookery occurred ...