I live in Tukwila & spend a lot of time on the Green River trail. During this year, like many other Tweeters, I've also noticed a large decrease in the number of violet green & barn swallows, as well as more rough winged swallows. At the same time, I have also seen many more house sparrows. Anything we can do to discourage the house sparrows would, I think, be worth the effort.
Mary Forrester