The Brown-headed Cowbird is a Brood Parasite (allaboutbirds.org). The female Cowbird will lay their eggs in nests of other species. Although some species are able to identify the different egg in their clutch most are forced to raise their foster child. Which really shows how strong instinct is, because how does a cow bird know how to be a cowbird if it’s not learning from it’s real parents?
The males are quite handsome with their brown head heads and iridescent black feathers shimmering purple tones (above). The female is more subdued with brown tones (below). [click on any picture to see larger image]
OTHER POSTS FEATURING THE BROWN-HEADED COWBIRD:
BCSONGBIRD 
I was happy to discover your post as I’ve been meaning to look up Brown-headed Cowbirds! Someone told me that our two-tone brown female Boat-tailed Grackles are often mistaken for these Cowbirds, but I never really investigated – Now I have your wonderful post to compare with our grackles!
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We don’t get the Boat-tailed Grackles on the west, so I had to look them up. Yes the colouration is quite similar for sure. Thanks for your comment!
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