Seasonal patterns in marine bird distribution over 15 nonbreeding seasons were identified for 11 species groups in Prince William Sound. The study highlighted dynamic movements into and out of PWS during the nonbreeding season, challenging the notion of a single “winter” period for marine bird distribution. Habitat use remained consistent across analyses, with water depth, distance from shore, and habitat type identified as key environmental factors. Birds were more likely to be present and in greater numbers closer to shore and in shallower water. Our results support the assertion that birds seek refuge during winter, with PWS’s superior winter habitat relative to the harsher conditions in the Gulf of Alaska.

Key environmental factors influencing marine bird distribution in Prince William Sound were water depth, distance from shore, and habitat type. Most species groups were more likely to be present and in greater numbers when closer to shore and in shallower water. Grebes, murrelets, mergansers, and small gulls were less likely to be present in open-water habitats. On the contrary, cormorants were more likely in mouths of bays and passages and open water, scoters preferred mouths of bays and passages, and murres were more likely in open water compared to bays. We also found that more than 40% of birds were near fish schools, but only 20% of fish schools had birds around them. Overall, birds targeted fish schools that were easier to reach.

When observing bird-humpback whale foraging dynamics, we discovered that humpback whales use forage flocks of seabirds as signals to find scattered prey resources. In observed interactions, humpback whales consistently acted as flock disruptors rather than facilitators. This behavior involved a single whale surfacing through an existing feeding aggregation, causing the aggregation to disperse. The findings suggest that humpback whales disrupt forage flocks by accessing prey resources rather than cooperating with the flocks in their feeding activities.