RESUMO
Some Arctic estuaries serve as substrate rubbing sites for beluga whales (Delphinapterus leucas) in the summer, representing a specialized resource for the species. Understanding how environmental variation affects the species' behavior is essential to management of these habitats in coming years as the climate changes. Spatiotemporal and environmental variables were recorded for behavioral observations, during which focal groups of whales in an estuary were video-recorded for enumeration and behavioral analysis. Multiple polynomial linear regression models were optimized to identify the effects of spatiotemporal and environmental conditions on group size, composition, and the frequency of behaviors being performed. Results suggest that belugas take advantage of environmental variation to express behaviors that 1) protect young, e.g., bringing calves close to shore during cloudier days, obscuring visualization from terrestrial predators; 2) avoid predation, e.g., rubbing against substrates at higher Beaufort sea states to obscure visualization, and resting during low tides while swimming on outgoing tides to avoid stranding; and 3) optimize bioenergetic resources, e.g., swimming during lower Beaufort sea states and clearer days. Predictive models like the ones presented in this study can inform conservation management strategies as environmental conditions change in future years.
