Date: 3/15/26 10:01 am From: 'Pete Sole' via mbbirds <mbbirds...> Subject: [MBBIRDS] Migration Musings
Hi birders,
Last night I checked Cornell's Birdcast Migration resources, and was
happy to see the beginnings of bird migration movement. Specifically, we
had a small bump of activity early in the evening, the second small
migration bump of the season. ( For those that are curious about the
data, see the Santa Cruz county migration dashboard
at: https://dashboard.birdcast.org/region/US-CA-087 )
My guess at this point, is that the migration activity is mostly birds
starting to leave, rather than arrive. But we've already had a number of
migrant species return. Three of five migrant species that I track, that
breed in my neighborhood, have already shown up; an early male Hooded
Oriole, multiple Violette-green Swallows, and one Allen's Hummingbird.
In the coming weeks I'll be looking for more of the same as well as,
Black-headed Grosbeaks, and Western Flycatchers, which have already
landed in other parts of the county.
Still present Golden-crowned and some White-crowned Sparrows, as well as
Yellow-rumped Warblers are molting, before they migrate to their
breeding grounds. In the case of the Golden-crowned Sparrows, they breed
in Alaska and Canada. Both, molting into breeding plumage and migration
flight, have very high energy requirements. So most species molt before,
or after arriving on their breeding grounds. Very few species molt into
breeding plumage and migrate at the same time. Those that do so, usually
molt at a temporary stop, before continuing on their journey, but even
then, there are exceptions.
Hermit Thrushes are still present, but in the coming weeks, they too
will leave our coast. Some heading as far north as Alaska, while perhaps
a small number, make a much shorter flight to the Santa Cruz mountains
to breed.
Migration, one of the wonders of the natural world.
