MOVEMENT OF WEANED NORTHERN ELEPHANT SEAL PUPS DURING THEIR FIRST AT-SEA FORAGING MIGRATION

Katie Saenger; California Polytechnic State University; esaenger@calpoly.edu; William T. Bean, Heather S. Harris, Lauren Campbell, Elizabeth Eby, Kate Riordan, Molly Murphy, Rhys Evans, Gita R. Kolluru, Heather E.M. Liwanag

The northern elephant seal (Mirounga angustirostris, NES) is a well-studied marine mammal known for engaging in long foraging migrations at sea. Adult male NES follow pathways along the coast towards Alaska and adult female NES follow pathways to open ocean. However, there is little to no information about newly weaned NES pup foraging behavior. This lack of knowledge is significant because NES have a mortality rate of >50% in the first year. This project aims to better understand the migratory pathways of NES during this critical life stage. We deployed satellite tags on newly weaned NES pups at Vandenberg Space Force Base (VSFB, est. 2016, n=10) and San Nicolas Island (SNI, est. 1949, n=5). We hypothesized that weaned NES pups would [1] prioritize near-site foraging areas and thus migrate shorter distances compared to adults, [2] exhibit no sexual divergence in their pathways, and [3] have pathways that differ between the two breeding sites. Examining these migratory pathways and comparing them between rookeries and years provides insight into important foraging grounds for this life stage, differences between breeding sites, and environmental influences on migration, which will inform the conservation and management of this species.

Military Lands - I   Student Paper