Consistent range-wide pattern in fall migration strategy of Purple Martin (Progne subis), despite different migration routes at the Gulf of Mexico

Autor: Bridget J. M. Stutchbury, Eli S. Bridge, Patrick M. Kramer, Kevin C. Fraser, Cassandra Silverio, John Barrow, John Tautin, Paul Mammenga, Nanette Mickle, David Newstead, Kelly Applegate, Tim Shaheen
Rok vydání: 2013
Předmět:
Zdroj: The Auk. 130:291-296
ISSN: 1938-4254
0004-8038
DOI: 10.1525/auk.2013.12225
Popis: The migration rate of Nearctic—Neotropic songbirds is expected to be influenced by whether the route is around or across migration barriers such as the Gulf of Mexico. To examine factors that influence fall migration strategies, we used light-level geolocators to track the journeys of 91 Purple Martins (Progne subis) originating from breeding colonies across the eastern range of the species. We expected individuals that crossed the Gulf of Mexico to have slower migration rates, and more stopover days in Central America to refuel after the crossing, than birds that took routes around the gulf. Owing to expected variability in conditions experienced by individuals en route, we anticipated that departure date would be a poor predictor of arrival date within and among populations. Despite widely separated breeding origins, one-way journeys of >7,000 km, and high variability in departure dates and routes, individuals showed a strikingly similar fall migration strategy. Fall migration featured a rapid...
Databáze: OpenAIRE