Marine habitat preferences of marbled murrelets in Haida Gwaii, BC

Effective spatial planning for seabirds depends on understanding what influences foraging habitat choices. I used a long running at-sea survey dataset (1997-2018) to develop a baseline understanding of marine habitat preferences of Marbled murrelets (Brachyramphus marmoratus) in Haida Gwaii, British Columbia, Canada. Persistence hotspot mapping showcased how distributions have remained similar over time. Murrelet usage was positively associated with being closer to streams, shallower waters, higher proportions of sandy sediment and closer proximity to abundant potential nesting habitat. Additional surveys conducted in 2018 and 2019 identified stratified water as a dynamic variable that positively influenced counts. Finally, an experiment utilizing avian deterrent kites showed that a lower daily proportion of murrelets were counted in locations adjacent to kites when they were flying than when they were not. Overall, my study shows that static variables are primary influencers of Marbled murrelet marine distribution, but dynamic variables such as thermal mixing and predator occurrence also play roles.