Thursday, November 15, 2012

Rusty vs. Brewer’s Blackbirds

On Tuesday Gerry Hoekstra and I discovered a dozen Brewer’s Blackbirds among some 75 Red-winged Blackbirds, all feeding in a recently fertilized corn field. Brewer’s Blackbirds are common in northern Minnesota, but less so elsewhere. According to Eckert, Brewer’s Blackbirds are less often seen during migration than are other blackbirds. Rusty Blackbirds, on the other hand, are common fall migrants in Minnesota. 

These two species can be difficult to tell apart (especially males in breeding plumage). In these fall birds note the uniformly dark wings of the Brewer’s Blackbird in the first photo. The winges of the Rusty Blackbird have chestnut edgings, as you can see in the lower photo. The Rusty Blackbird’s supercilliary stripe is much bolder than the face of the Brewer’s. Finally note the habitat—Rusty Blackbirds favor swampy or wet areas whereas Brewer’s are often found in dry fields and feedlots. I took the Rusty Blackbird’s photograph on 26 October at the Bass Ponds near the Minneapolis Airport.

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