Migratory shearwaters integrate oceanic resources across the Pacific Ocean in an endless summer.
Electronic tracking tags have revolutionized our understanding of broad-scale movements and habitat use of highly mobile marine animals, but a large gap in our knowledge still remains for a wide range of small species. Here, we report the extraordinary transequatorial postbreeding migrations of a small seabird, the sooty shearwater, obtained with miniature archival tags that log data for estimating position, dive depth, and ambient temperature. Tracks (262+/-23 days) reveal that shearwaters fly across the entire Pacific Ocean in a figure-eight pattern while traveling 64,037+/-9,779 km roundtrip, the longest animal migration ever recorded electronically. Each shearwater made a prolonged stopover in one of three discrete regions off Japan, Alaska, or California before returning to New Zealand through a relatively narrow corridor in the central Pacific Ocean. Transit rates as high as 910+/-186 km.day-1 were recorded, and shearwaters accessed prey resources in both the Northern and Southern Hemisphere's most productive waters from the surface to 68.2 m depth. Our results indicate that sooty shearwaters integrate oceanic resources throughout the Pacific Basin on a yearly scale. Sooty shearwater populations today are declining, and because they operate on a global scale, they may serve as an important indicator of climate change and ocean health.
Shaffer
Scott A
SA
Ecology and Evolutionary Biology, University of California, Santa Cruz, CA 95064, USA. shaffer@biology.ucsc.edu
Tremblay
Yann
Y
Weimerskirch
Henri
H
Scott
Darren
D
Thompson
David R
DR
Sagar
Paul M
PM
Moller
Henrik
H
Taylor
Graeme A
GA
Foley
David G
DG
Block
Barbara A
BA
Costa
Daniel P
DP
D000823:Animal Identification Systems; D025041:Animal Migration / Q000502:physiology*; D000818:Animals; D001717:Birds / Q000502:physiology*; D010140:Pacific Ocean; D011891:Rain; D012621:Seasons