Meeting Abstract
Offspring of capital breeders, such as the northern elephant seal (rounga angustirostris), are nursed exclusively from maternal body reserves. Previous investigations have shown that milk energy delivery rate in northern elephant seals increases with the size and age of the female. Milk energy intake and offspring storage data (n=47) suggests impacts of maternal age on growth efficiency that are independent of rates of energy delivery. To better understand the mechanisms underlying this effect of maternal age, behavioral data were collected from pups of 46 known-age females, from parturition to weaning, across six years and three different sites along the Central California Coast, representing 3954 seal-hours of observation. Pup behaviors were divided into five mutually exclusive categories that reflected pup energetics (e.g. locomotion vs. suckling). Maternal age had a significant effect on pup behavior. Pups of older females spent more time suckling and resting, while pups of younger females spent more time vocalizing, locomoting, or distant from their mother. Pup behavior also varied strongly with days post-partum and time of day. The magnitude of these effects varied between rookeries, suggesting influences of harem topography and environmental features on pup behavior. Together these finding suggest direct impacts of maternal breeding experience on pup behavior and growth efficiency.
