title: Migratory shearwaters integrate oceanic resources across the Pacific Ocean in an endless summer.
abstract: 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.
authors.affiliation: Ecology and Evolutionary Biology, University of California, Santa Cruz, CA 95064, USA. shaffer@biology.ucsc.edu
authors.forename: Scott A
authors.initials: SA
authors.lastname: Shaffer
authors.forename: Yann
authors.initials: Y
authors.lastname: Tremblay
authors.forename: Henri
authors.initials: H
authors.lastname: Weimerskirch
authors.forename: Darren
authors.initials: D
authors.lastname: Scott
authors.forename: David R
authors.initials: DR
authors.lastname: Thompson
authors.forename: Paul M
authors.initials: PM
authors.lastname: Sagar
authors.forename: Henrik
authors.initials: H
authors.lastname: Moller
authors.forename: Graeme A
authors.initials: GA
authors.lastname: Taylor
authors.forename: David G
authors.initials: DG
authors.lastname: Foley
authors.forename: Barbara A
authors.initials: BA
authors.lastname: Block
authors.forename: Daniel P
authors.initials: DP
authors.lastname: Costa
mesh_terms: D000823:Animal Identification Systems; D025041:Animal Migration / Q000502:physiology*; D000818:Animals; D001717:Birds / Q000502:physiology*; D010140:Pacific Ocean; D011891:Rain; D012621:Seasons