Ringed seal (Pusa hispida) lair habitat, emergence timing, and reproductive ecology in relation to snow characteristics in a changing Arctic

Abstract

Ringed seals (Pusa hispida) are ice-associated Arctic marine mammals that are a vital resource for Arctic Indigenous peoples, and are ecologically important as the primary prey for polar bears. These seals use snow-covered lairs on sea ice to rest and to protect young pups from hypothermia and predation during winter. As lairs melt and collapse later during spring, the seals emerge onto the surface of the ice to bask and molt. However, lair habitat requirements and the timing of emergence from snow lairs are poorly understood, and these uncertainties limit our ability to anticipate when and how climate change will affect ringed seals, and hinder interpretation of aerial survey data for estimating abundance and monitoring population trends. This dissertation explores associations between ringed seals and environmental variables in and around Alaska during the spring denning period. Chapter 1 uses a combination of knowledge co-production, drone-based aerial surveys, and on-ice data collection to quantify fine-scale habitat selection patterns in Kotzebue Sound, Alaska. Chapter 2 quantifies broader-scale selection and emergence patterns in the Bering and Chukchi seas using previously collected data from the largest aerial surveys ever conducted for ringed seals. Lastly, Chapter 3 uses a novel approach of estimating ringed seal emergence timing and the onset of basking behavior from haul-out data from seals in Alaska and Canada. Together, these chapters advance our understanding of the relationships between ringed seals and snow, sea ice, melt, and air temperature in a changing Arctic, with implications for monitoring and management.