How do cowbirds affect the nesting of songbirds?
One example of a songbird aising young if it nests deep in the forest). If scarlet tanagers nest close to forest edges, their eggs are often pushed out of their nests by brown-headed cowbirds. Then the cowbirds lay their eggs in the nest, leaving the tanagers to raise the young cowbirds and increasing the cowbird population instead of the songbird population. Cowbirds are rarely found in the center of large forests. For more information, visit www.dnr.state.md.us/forests/healthreport/threatened.html.
