Big Bird, Little Bird

The chipping sparrow skipped around the fat, hungry baby bird and then, amazingly, came back and fed the Baby Huey multiple times. The baby was drab gray and 2-3 times larger than the chipping sparrow. I thought it was a house finch, but it was larger than a house finch. Stumped, I tried to photograph this startling behavior through my window, but the images did not do the birds justice. I did get enough of Big Bird to later identify that it was a cowbird! Turns out that cowbirds are brood parasites. The poor chipping sparrow and the baby cowbird were bonded, but the sparrow was working overtime feeding the giant thing.