See the Smithsonian Migratory Bird Center page with Rusty Blackbird news - it is the fastest-declining songbird in North America. In this article Russell Greenberg explains what is known about this species and what's happening.
If you are like me and love blackbirds, you would probably enjoy Alex Skutch's book: Orioles, Blackbirds and Their Kin (1996, Univ. of Arizona Press). I've had it sitting on my bookshelf for several years, but am reading it now. Highly recommended, like all of Skutch's books. Skutch himself was as fascinating as the birds he studied. Learn about his amazing life here.