Hi Tweets,
The Slater Museum on the University of Puget Sound campus in Tacoma is happy to take dead birds. Common birds are often being used in education kits for K-12 classes and others are put into the collection. I will put out a special request here for Anna's Hummingbirds, as we have are currently doing research on rapid evolution in Anna's. And as other Tweets mentioned, the Burke Museum at the UW takes specimens as do some of the local Audubon chapters. When you find a dead bird, put it into a ziploc plastic bag along with a piece of paper with the date and locality and put it into your freezer until you can take it to your local museum.
Thanks very much,
Peter Wimberger
Slater Museum
Tacoma, WA