File:Molothrus ater (brown-headed cowbirds) (Newark, Ohio, USA) 2.jpg

English: Molothrus ater (Boddaert, 1783) - brown-headed cowbirds (left: female; right: male) in the western part of Newark, Ohio, USA. (photo by Mary Ellen St. John)

Male brown-headed cowbirds have a bluish-black colored body and a chocolate brown-colored head. Females are grayish-brown in color. Bills are finch-like. Female cowbirds lay their eggs in the nests of other passerines, usually smaller birds. Young cowbirds are larger than the offspring of the host nest. The cowbird usually pushes the host's own young out from the nest, or starve them by taking most of the food brought by the unwitting host parents. This is called parasitic nesting behavior.

Classification: Animalia, Chordata, Vertebrata, Aves, Passeriformes, Icteridae

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Birds are small to large, warm-blooded, egg-laying, feathered, bipedal vertebrates capable of powered flight (although some are secondarily flightless). Many scientists characterize birds as dinosaurs, but this is consequence of the physical structure of evolutionary diagrams. Birds aren’t dinosaurs. They’re birds. The logic & rationale that some use to justify statements such as “birds are dinosaurs” is the same logic & rationale that results in saying “vertebrates are echinoderms”. Well, no one says the latter. No one should say the former, either.

However, birds are evolutionarily derived from theropod dinosaurs. Birds first appeared in the Triassic or Jurassic, depending on which avian paleontologist you ask. They inhabit a wide variety of terrestrial and surface marine environments, and exhibit considerable variation in behaviors and diets.