On our 28 March arrival update, we highlighted the late arrival of Chimney Swifts into the US this spring:
— Team BirdCast (@DrBirdCast) March 28, 2017
In the last several days, we’ve seen an increase in eBird reports of swifts by nearly 600%, and the 10-day delay we wrote about earlier seems to have evaporated! Here is the latest graph (current year in black):
The sightings map is also starting to fill out nicely, with the current range front now well into North Carolina:
Compare directly with the OLD map, from just a few days ago:
This is but one example of how migratory birds are incredibly consistent, yet often incredibly flexible at the same time. Citizen science data from eBird are helping us better understand their behavior.