MOLTING MECHANICS: CHARACTERIZING SURFACE TEMPERATURES DURING THE INITIAL MOLT OF NORTHERN ELEPHANT SEAL (MIROUNGA ANGUSTIROSTRIS) PUPS

Rachel T Survilas; California Polytechnic State University San Luis Obispo; rsurvila@calpoly.edu; Halley Jae Carson, Dr. Heather E.M. Liwanag

A vital life history stage for many animals is molting, or renewal of the outermost layer (feathers, hair, skin). Like other pinnipeds (seals, sea lions, walrus), northern elephant seal (NES) pups are born with neonatal fur that they molt into a juvenile coat after weaning. The transition between pelts is likely to affect thermoregulation. One strategy is to increase blood flow to specific body regions (called “thermal windows”) to help dissipate excess heat. The goal of this study was to examine whether NES pups use thermal windows to facilitate their natal molt. We used an infrared camera to take thermograms of molting NES pups at the Piedras Blancas rookery. We recorded concurrent environmental variables (wind speed, air temperature, solar radiation) to determine which factors impacted molting pup thermal profiles. We found that thermal windows were not associated with molted regions; windows were found primarily in low insulation areas (head and flippers) and randomly along the trunk. Wind speed negatively affected the presence of windows, whereas ambient temperature and solar radiation positively impacted surface temperature. This is the first study to investigate thermoregulation during the NES natal molt. Future work will compare these results to the molt of older age classes.

Natural History of Mammals 
Thursday 1:55 PM
   Student Paper