Well, the cowbird was passed over for the Parent-of-the-Year award once again. Rosemary Conroy explains why the cowbird is so unpopular.
Welcome to this week's edition of Something Wild. I?m Rosemary Conroy for the Society for the Protection of New Hampshire Forests.
When you think of birds in spring, most people picture mother birds sitting on eggs or frantic parents flying back and forth to fill their hungry chicks? beaks with bugs.
But some birds take a more unorthodox approach to passing on their genes. Brown-headed cowbirds, for example, leave all the problems of chick-rearing to others. These ?brood parasites,? as they are known, simply sneak into other bird?s nests, lay their eggs and then disappear from the parental scene forever.
Cowbirds, who aren?t too choosy, try to take advantage of more than 200 species of songbirds.
Now, the warbler, finch or sparrow that finds this extra egg in their nest react in various ways. Some destroy the egg and some simply accept it as their own ? even when the egg is a completely different color!
The cowbird typically targets smaller birds than itself, so its chick often hatches before the others. Consequently, it will be bigger and stronger than its adopted siblings. And since most songbird parents tend to feed the chick that makes the most fuss ? the cowbird often out-eats its nest-mates.
As you can imagine, brown-headed cowbirds are widely disliked by bird-lovers. For years they were blamed for the rapid decline in songbird numbers and huge efforts were undertaken to eradicate them.
But now scientists are discovering that cowbirds don?t do as much damage to songbird populations as originally thought. Fewer than 3% of their chicks make it. Habitat loss is much more responsible for decline in bird species than these alleged feathered fiends could ever be.
Cowbirds developed their hit and run parenting style because they used to make their living following migratory herds of bison. When the bison were wiped out, the cowbirds adapted to the domestic livestock that took their place. Hmm I wonder what they?ll do next?
Something Wild is a joint production of the Society for the Protection of New Hampshire Forests, New Hampshire Audubon, and NHPR.
For Something Wild, I?m Rosemary Conroy.
