Monday, August 20, 2018

Warbler Guy, which migrating warbler arrives first on the East Coast? Which warbler arrival shall I expect on the West Coast? Warbler migration has begun?

Lori, those are great questions.

The brief answer is look for the following warblers to initially appear as true returning migrants on the East Coast from the Mid-Atlantic north:

- Louisiana Waterthrush
- Palm Warbler
- Common Yellowthroat
- Yellow-rumped Warbler

For the West Coast, it's even more simplified:

- Orange-crowned Warbler (photo shown here) is often the most common returning nesting species, typically arriving by late February to early March, if you're in the San Francisco Bay Area where I live.


March 6 is the mean annual arrival date for this species on the coast in W. Marin Co. at the Palomarin (near Bolinas) bird banding station, based on 1967-1989 records. The earliest return date in this span is 2/27 and 3/16 was the latest.

Palm, Wilson's, and Yellow Warbler may also be early returnees on the West Coast, though it's challenging to definitively determine if sightings of these species are true migrants or "over-wintering" individuals.

Some Orange-crowned individuals in the Bay Area also may "over-winter," as Christmas Bird Count surveys in the San Francisco Bay Area often record this species and rare to periodic reports for this species persist throughout the winter during most years from Bay Area counties. In this case, if I hear an associated Orange-crowned song in February or March, then I usually deem the aria a returning migrant individual.

Happy birding, Daniel
danieledelstein at att dot net
warblerwatch dot com

1 comment:

Anonymous said...

No question, the first migrating warblers on the eastern half of the country are yellow warblers and Tennessee warblers. Palm warblers and yellow-rumped warblers arrive much later.