Tracking the migrations of Pacific Golden-Plovers (Pluvialis fulva) between Hawaii and Alaska: New insight on flight performance, breeding ground destinations, and nesting from birds carrying light level geolocators

This study is the first in which light level geolocators (data loggers) were deployed on Pacific Golden-Plovers Pluvialis fulva. In spring 2009 and 2010, we logger-equipped a total of 24 plovers at wintering grounds onOahu, Hawaii; 22 returned in the subsequent fall migrations, and of these 20 were recaptured. Almost all of the recovered geolocators had archived the full roundtrip to Alaska including nesting locations. Transpacific flights were nonstop along direct north–south pathways. On average, the northward passage required approximately 3 days and covered about 4,800 km; the southward around 4 days and 4,900 km. Ground speeds fluctuated widely during flights (almost certainly because of variable winds); mean ground speeds were estimated at 63 kph in spring, 58 kph in fall. The capacity of this plover for nonstop flight remains unknown; however our results indicate that it exceeds 5 days. All 20 birds nested in southerly parts of the Alaska breeding range, from the Yukon–Kuskokwim Delta to nearly the tip of the Alaska Peninsula, indicating major migratory connectivity between Hawaii and those regions. Geolocator archives during the time birds were on breeding grounds showed periods of successive days with erratic light level patterns (“noise”). Such noise seemed a clear indicator of nesting activities, and also of hatching success or failure.