Relationship between the female attendance pattern and pup growth rate in the South American sea lion (Carnivora)

Changes in the duration and frequency of foraging trips by female otariids may result changes lactation bouts hence influence pup growth rate, unless females modify milk energy density and/or total amount delivered depending on trip duration. To test this hypothesis South American sea lions, we measured two attendance pattern components (foraging haul-out duration) three diving behaviour nursing (dive time, bottom time number dives per h) at different rookeries Uruguay Argentina, composition their milk, rate pups. Female durations depended sex weight, whereas body mass durations. By contrast, dive variables were independent or sex. Pup was also duration, with as only significant variable. This suggests that individual differences play a minor role determining rates during first weeks after birth.