Birders

I had a strange bird on the deck last week and made an effort to identify it. Turns out it was a recently fledged cowbird and it was being fed by a pair of Carolina Wrens.

Brown-headed Cowbirds are brood parasitic - meaning they lay their eggs in the nests of other birds. In all cases, they are laid in the eggs of smaller birds. The young cowbirds gather all of the attention of the host nest's adults and starve out the host's young.

In my case, the cowbird was being fed by a bird less than half its size and the wrens were probably working themselves to death to feed the bird that killed their young.

Having said all of this, cowbirds do this because they had historically followed herds of grazing animals (e.g., buffalo/bison, antelopes, etc.) and this didn't leave a lot of time for proper nesting - so they displaced the young of other birds who would raise cowbirds as their own.