Date: 6/30/26 6:56 pm From: Dennis Paulson via Tweeters <tweeters...> Subject: [Tweeters] eastern WA birds moving west
Hello, tweets.
Looking in the eBird report, the amazing number of Yellow-breasted Chats reported in western WA recently stand out. Redstarts seem more frequent, Lazuli Buntings are seen all over the place, and we discussed earlier the many Chipping Sparrows turning up west of the Cascades, So I came up with a simple hypothesis to explain all these birds that we have long considered eastside birds that are turning up on the west side.
I hypothesize that the tremendous and ongoing destruction of eastside habitat, especially at lower elevations in the Columbia Basin, may be sending these birds westward. I have been here for over 50 years, and the changes east of the mountains have been horrendous from the standpoint of the environment. Not only has so much habitat been destroyed, but because of the use of pesticides in agriculture, the insect populations have surely been reduced to a tiny fraction of what they once were.
It’s quite possible that natural selection is playing a part in this, with birds on the west side more likely to have a successful breeding season, and their young returning to where they were raised. Presumably an analysis of the Breeding Bird Survey results would furnish a lot more data to test my hypothesis.
