Trans-equatorial migration links oceanic frontal habitats across the Pacific Ocean: year-round movements and foraging activity of a small gadfly petrel

Stejneger’s petrels, endemic to the Juan Fernández Islands, undertake an unprecedented trans-equatorial migration spanning 54,725 km across the Pacific Ocean, linking oceanic frontal habitats from the Sub-Antarctic Front to regions near Hawaii and Japan. This triangular migration pattern, unique among seabirds, involves a detour toward New Zealand before heading east at 40–50°S, likely leveraging Antarctic circumpolar winds. The study used geolocator-immersion loggers over two years to track year-round movements, phenology, habitat use, and activity patterns of 10 individuals. Birds spent >75% of their time flying during breeding and migration but reduced flight activity during non-breeding, possibly due to feather molt. Their strong preference for oceanic frontal regions, particularly the North Pacific Transition Zone Chlorophyll Front, underscores the critical need to protect these remote High Seas habitats.

Clay, T. A., & Brooke, M. d. L. (2024). Trans-equatorial migration links oceanic frontal habitats across the Pacific Ocean: year-round movements and foraging activity of a small gadfly petrel. Marine Biology, 171(2). https://doi.org/10.1007/s00227-023-04373-3