Meeting Abstract

38.9  Tuesday, Jan. 5  Presence of the mother influences the stress response in harbor seal pups DI POI, C.; ATKINSON, S.*; HOOVER-MILLER, A.; BLUNDELL, G.; University of Alaska Fairbanks, School of Fisheries and Ocean Sciences, Juneau AK; University of Alaska Fairbanks, School of Fisheries and Ocean Sciences, Juneau AK; Alaska Sea Life Center, Seward AK; Alaska Department of Fish and Game’s, Juneau AK atkinson@sfos.uaf.edu

For many species, the presence of a significant social figure down-regulates physiological responses and hence serves to buffer the individual against stressful stimuli. We studied how the presence of the mother regulates both behavioral and endocrinological responses of harbor seal (Phoca vitulina) pups to a stressful event (capture and sampling). Blood samples were taken for circulating cortisol and 5-HT quantification for mother-pup pairs, dependent pups alone (caught without their mother), weaned pups alone and single adult females. Behaviors of pups, vocalisation and agitation levels, were recorded as well. All seals were captured, sampled and released in Endicott and Tracy Arms, Southeast Alaska during the 2009 pupping season. Neither circulating cortisol nor 5-HT concentrations were affected by time passed between the capture and blood collection. Accompanied pups showed significantly higher levels of agitation and vocalisations than both dependent pups alone and weaned pups, possibly due to the close presence of their mother during the sampling. Moreover, vocalizations in harbor seal pups are known to have a role maintaining contact with the mother, while they naturally subside once they have weaned. The presence of the mother significantly reduced the cortisol response of her pup compared to that measured for pups alone (both dependent and weaned pups). The mothers with pups had higher concentrations of cortisol compared to single females. Differences in 5-HT levels observed between pups or females were not conclusive. These results provide the first evidence that the presence of the mother may decrease the magnitude of the glucorticoid stress response in her offspring in phocids.