Breeding in the increasingly fragmented boreal forest of Canada ( see http://www.borealbirds.org/forest.shtml ), this species' decreasing numbers are of concern to scientists. It is included in the "Yellow" (i.e., "Threatened") section of the Audubon Watchlist ( http://audubon2.org/webapp/watchlist/viewWatchlist.jsp ).
At 3:45 this afternoon, I found a male Rusty Blackbird perched on a smallish deciduous trees on the bank of the Winooski. I observed it for at least five minutes through my binos: its smaller overall size, slim curved bill, and squared off tail ruled out Grackle. Not having seen a R.B. in perhaps two or three years, I checked it features against my Peterson, and there was no question about the ID. It was not vocalizing, at least not that I could hear.
Birding from 2 p.m. to 4:30, with a falling barometed and graying skies, we were disappointed but not surprised not to see the warblers reported from this location.
We did observe: a male E. Tohee and a male Wood Duck, as well as all the other common breeding species already in residence.
The wildflowers were breathtaking. I won't enumerate species, since this is a birding list.