David M. Larson
In the fall, Blackpoll Warblers (Setophaga striata) are celebrated for the exercise in identification and for the appreciation of their long and difficult impending over-water migration. However, in the spring, when local birders find these warblers, a shading of existential dread often colors the experience. "Oh no, migration is almost over!" Maybe that is why relatively little has been published about spring Blackpoll migration.
Because Blackpolls breed across the North American continent in the boreal forests of the United States and Canada and migrate from their South American wintering grounds past a broad array of bird banding stations, they would seem to be a good model for studies on the drivers, modulators, and phenology of migration. They are also a rapidly declining species of concern, meaning that study could illuminate issues of conservation action or further research. Elucidating parameters of spring migration in Blackpolls was the goal of the research reported by Covino et al. 2020. The authors assembled spring records, collected between 1960 and 2017, from 28 birdbanding sites, stretching from Florida and Mississippi up the East Coast, across the upper Midwest, to western Canada and Alaska. Data were retrieved from the United States Geological Survey (USGS) Bird Banding Laboratory data base. The researchers also reached out to individual banding stations for additional data, such as wing chord and mass, not usually recorded in the USGS data base.
To view the rest of the article you'll need to subscribe
. Bird Observer publishes original articles on birding locations, on avian populations and natural history, on regional rarities, field notes, field records, photographs, and art work.