The brown headed COW bird.   The Brown-headed Cowbird is well known--and widely disliked--for its practice of laying eggs in the nests of other species. 

Historically, Brown-headed Cowbirds probably followed herds of bison, walking behind them to take advantage of food kicked up in the bison's wake,  Now they follow cattle and other large grazers in much the same way. They almost always forage on the ground, but also lurk about in trees and bushes, mostly watching quietly for nests to parasitize.  Editor's note:  The BHCB is a SCAVENGER by nature and a parasite to other productive bird species... HMMMMM.

They never build nests or raise their own young.  Females lay eggs in other birds' nests and leave the rearing to other species. They find nests to parasitize by looking for birds building nests, either by walking along the ground, perching quietly in shrubs or trees, or making noisy flights back and forth, possibly to flush potential hosts. The female generally chooses an open cup-nest to parasitize, and usually lays one egg per nest. She waits to lay the egg until the host bird has at least one egg in its nest, and often removes one egg from the nest before laying her own. She continues the process over a period of about a month and can lay up to 40 eggs a season.  

So even the CUSTODIAL HCGUBM draws a parallel in objecting to financially supporting her own brood and trying to pass off child rearing to others or the television, yet continues to breed.   All the while chirping that she is "doing it all on her own."

-excerpts from birdworld.org