Date: 9/9/20 1:54 pm From: Joel Geier <clearwater...> Subject: [obol] Post-breeding Oregon Vesper Sparrow flock north of Corvallis
At a monitoring site on grazing land in the Soap Creek Valley north of Corvallis this morning, I encountered a flock of Vesper Sparrows that must have numbered at least 25 to 30 birds. At least 9 of the birds in the flock were color-banded birds that nested one the same site (mainly hatch-year birds but a couple of older birds). A few Chipping Sparrows were loosely associating with the Vesper flock.
This site had about a dozen pairs during the nesting season but they were spread out over a large area. This coalescence into larger flocks seems to happen around the end of August and into the first half of September. There was still one older female hanging out by herself in the area where she nested, about 1/4 mile away from the main flock.
Some folks have been asking about observations of bird behavior being affected by the dim light and pall of smoke hanging over our area right now. My impression was that these birds were behaving similar to a couple of days ago when there were about 15 birds in the flock, though perhaps a bit more furtive, and spending less time perched up in shrubs (possibly more due to the variable wind than the smoke).
One noticeable change from two days ago was that I didn't hear either of the two male Northern Pygmy Owls that have been vocalizing just about every time I've been out on this site since March (including on 7 Sep). Western Bluebirds were very active and I had a flyover of half a dozen Evening Grosbeaks.
Human activity seems to be at a low level, with restrictions on chainsaws, mowers, etc. in effect due to the risk of fire. So things are very quiet out there.