Natural History Wanderings

The New York Times recently wrote about the conflicts between Mockingbirds and Cowbirds. Cowbirds, are brood parasites, which means they lay eggs in the nests of other birds and get the other bird to take on the task of incubating and raising the Cowbird’s young. Cowbirds also peck holes in the host in the eggs of the host bird’s eggs to reduce competition for the Cowbird’s own young.

In monitoring Mockingbird nests, it was observed that Mockingbird’s aggressively attacked the Cowbirds. However, the Cowbirds allowed the attacks and continued to lay eggs while being attacked. In spite of the eggs still being laid the attacks did result in protecting the Mockingbird eggs from being pecked by the Cowbirds. Even though the Mockingbirds end up still raising some Cowbirds, the Mockingbird chicks are bigger and compete very successfully with the Cowbird Chicks.

Read more at: In a Bird’s Nest, an Animal Behavior Puzzle – NYTimes.com

See video of Mockingbird attacking intruding Cowbird while Cowbird lays egg in Mockingbird nest at: ScienceTake: Angry Birds