Adult female and male Brown-headed Cowbird
photo by Lisette Lebaillif
Human development of the land has caused fragmentation of forest habitat and resulted in a great increase in the edge habitats favored by Brown-headed Cowbirds, and a reduction of forest-interior habitats where they don’t like to venture. As a result, a number of forest birds' nests are now being used by Brown-headed Cowbirds at an increased rate.
There are 144 different host species documented that raise Brown-headed Cowbird young. Several published studies on the subject have found adult cowbirds check in with young cowbirds while the youngsters are still living with other species. The adult cowbirds help teach fledglings cowbird-specific behaviors before they leave their foster homes.
|Eastern Phoebe nest with 5 phoebe eggs & 1 Brown-headed Cowbird egg via Wikimedia Commons|
In late summer cowbirds flock together with other cowbirds. Chatter calls, as well as other visual cues help with recognition of their own species. The theory is that cowbirds and other parasitic birds possess a simple behavioral trait or cue that is species specific and helps them recognize themselves as cowbirds.
- How Do Cowbirds Learn to Sing? http://goo.gl/n6kYS
- Brown-headed Cowbirds http://lansingwbu.blogspot.com/2009/05/cowbirds.html
- How Do You Tell a Female Indigo Bunting from a Female Cowbird? http://goo.gl/SpQUX