April 29th
It's Chimney Swift migration time here in the US now, and will last for the next few weeks as the swifts (technically we have Vaux's Swifts here on the West Coast) move north in a wave from their wintering grounds in Central America, to nest as far north as Southern Alaska.
What happens during migration is they gather in flocks right at dusk over towns, wheel around together in a big circling group, and then suddenly, apparently on cue, down the (specially selected) chimney they funnel, like water down the drain, to roost together for the night.
It's kind of a classic bird-type thing to see, if you are hip to where and when it happens.
Oregon and Washington are split north and south down the middle by the Cascade Range : the wet highly-populated rainy wet valley on the west side, and the dry High Desert with it's small isolated towns on the east side.
Over in the valley, they can get 10,000 swifts at the big Chapman School chimney in Portland.
Over here, in our little desert towns, each town can get a couple of hundred on the better evenings
I've been heading down to our chimney for the last few nights, and we got 40 one night, and about 55 tonight.
I was the only one down there this evening, and just me and another person the night before.
Right in old downtown, in the chimney of probably the coolest old building in town, but kind of out of the main traffic flow, so a really nice quiet place to hang out..
Will there be more swifts in the coming days ? And how long will it take before they finish passing through ?
A very nice way to spend that special hour right at dusk, with Spring on the way.
If you live in this part of the country, you might want to check with your local bird club, and see if anyone will give you the lowdown on the chimney in your town. I suspect the same thing is going on on the East Coast now too.
And it will happen again in the Fall.
A pretty cool thing to be able to say you've seen.

sleeantagh:
Very cool. Bozeman, MT is as far west as I have been. So far...