Regarding spring migration, most species range maps (Cornell, Sibley, Peterson)
extend from Mexico to the Arctic. But eBird.org/science, thanks to
international postings, recently offers very broad range maps, giving a fuller
picture of the awesome movement of migrating birds.
For example, the lowly House Wren, very drab with a bubbly song, weighing less
than ½ an ounce, is the most widely distributed bird of the Americas. Barb and
I were happy to see and hear our firsts of the season yesterday at Bear Creek
Lake Park, three new arrivals on different territories along the creek, singing
their hearts out.
Here is an eBird animation of House Wren migration: https://ebird.org/science/status-and-trends/houwre/abundance-map-weekly.
I find it amazing and humbling that this tiny bird eagerly moves so far every
spring.
(Troglodytes Aedon was one of the two pets of King Friday
the XIII in Mister Rogers' Neighborhood. Trog, as the King called him. )
Thank you, eBird, for these excellent maps.
Happy spring!
Tom Wilberding
Littleton, Colorado