The first documentation of the Nearctic-Paleotropical migratory route of the Arctic Warbler

• Main Authors: Adams, Evan, Stenhouse, Ian, Gilbert, Andrew, Boelsma, Jill, Gress, George, Weidensaul, Scott, Grigsby, Charles, Williams, Emily, Phillips, Laura, McIntyre, Carol
• Format: Other/Unknown Material
• Language: unknown
• Published: Authorea, Inc. 2022
• Subjects: Arctic; Phylloscopus borealis; Alaska
• Online Access: http://dx.doi.org/10.22541/au.165218046.65655137/v1

The Arctic Warbler (Phylloscopus borealis) is a cryptic songbird that uses a 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. These results suggest that Arctic Warblers may migrate further overwater than previously thought and provide hitherto unknown information on stopover and wintering locations.