The first documentation of the Nearctic-Paleotropical migratory route of
the Arctic Warbler
Abstract
The Arctic Warbler (Phylloscopus borealis) is a cryptic songbird with an
uncommon Nearctic-Paleotropical migratory strategy. Using geolocators,
we provide the first documentation of the migratory routes and wintering
locations of two territorial adult male Arctic Warblers from Denali
National Park and Preserve, Alaska. After accounting for position
estimation uncertainties and biases, we found that both individuals
departed their breeding grounds in early September, stopped over in
southeastern Russia and China during autumn migration, then wintered in
the Philippines and the island of Palau. Our documentation of Arctic
Warbler wintering on Palau suggests that additional study is needed to
document their wintering range. Our results indicate that Arctic
Warblers migrate further overwater than previously thought and provides
hitherto unknown information on stopover and wintering locations.