The brown-headed cowbird’s habit of laying its eggs in the nests of other birds is well known.  The popular belief is that once a female cowbird lays an egg in the nest of another species she never returns.  According to researchers, we now know this is not always the case.

       Research has revealed that female cowbirds actually monitor the nests where they have placed an egg.  If she finds that the host bird tossed her egg aside, she often destroys host’s eggs.  If the host bird attempts to renest, this gives the cowbird another chance to lay another egg of her own.