|Female brown-headed cowbird|
The genus Molothrus contains:
|Image||Scientific name||Common Name||Distribution|
|Molothrus rufoaxillaris||Screaming cowbird||north east and central Argentina, south east Bolivia, central Brazil and throughout Paraguay and Uruguay|
|Molothrus oryzivorus (formerly in Scaphidura)||Giant cowbird||southern Mexico south to northern Argentina, and on Trinidad and Tobago|
|Molothrus aeneus||Bronzed cowbird||southern U.S. states of California, Arizona, New Mexico, Texas, and Louisiana south through Central America to Panama|
|Molothrus bonariensis||Shiny cowbird||South America|
|Molothrus ater||Brown-headed cowbird||southern United States and Mexico|
The non-brood parasitic baywing was formerly placed in this genus; it is now classified as Agelaioides badius.
Cowbirds eat insects, including the large numbers that may be stirred up by cattle. In order for the birds to remain mobile and stay with the herd, they have adapted by laying their eggs in other birds' nests. The cowbird will watch for when its host lays eggs, and when the nest is left unattended, the female will come in and lay its own eggs. The female cowbird may continue to observe the nest after laying eggs. If the cowbird egg is removed, the female cowbird may destroy the host's eggs to dissuade further removals, according to the Mafia hypothesis.
- Jeffrey P. Hoover; Scott K. Robinson (13 March 2007). "Retaliatory mafia behavior by a parasitic cowbird favors host acceptance of parasitic eggs". Proceedings of the National Academy of Sciences. Retrieved 26 August 2009.
|Wikisource has the text of The New Student's Reference Work article Cowbird.|