Brown-headed Cowbird (Molothrus ater)
   
 
Narrative and Science Lens
 
For these birds, which do not nest, incubate or brood their eggs, defend or feed their young, but instead lay each egg in the nests of others, to be raised by foster parents, the act of sneaking their eggs into the right nest is critical. The potential host-victims may eject the egg, bury it under a layer of nesting material, abandon the nest, or make lousy foster parents. Or they may successfully rear the cowbird.

Among species commonly seen on campus, Brown-headed Cowbirds frequenly or commonly victimize/parasitize Common Yellow-throats, Red-winged Blackbirds, California Towhees, Spotted Towhees, and Song Sparrows, and uncommonly target Bewick’s Wrens, Dark-Eyed Juncos, Bullock’s Orioles, and House Finches. Only rarely do they target Mourning Doves, White-breasted Nuthatches, Western Bluebirds, and American Robins.
 
  Campus Locations
Fairly common breeder in a variety of habitats virtually throughout campus, less common during the nonbreeding season. Laying its eggs in the nests of other species, the Brown-headed Cowbird has been observed parasitizing the California Towhee (the most frequent cowbird host on campus [Steve has this been studied?]).
  Campus sustainability
  Stealing Parental Care: In a 1985 report Friedmann and Kiff found more than 220 host species victimized (received a cowbird egg) and 144 species parasitized (reared cowbird young). Targets usually ranged in size from .35 ounces (kinglets) to 5.3 ounces (meadowlarks)
.      What you can do
       1. R
       2. I
       3. S
  Science
       Essays from The Birder’s Handbook:
            Brood Parasitism; European Starlings; Range Expansion
       References: Darley, 1982; Friedmann and Kiff, 1985; Teather and Robertson, 1986.
       Videos:
 
  Art
       Photos:
            Rohan Kamath: Brown-headed Cowbird (male and female)
       Drawings and Paintings:
            DW drawing after Audubon
 
  To add reports or images please submit them via the Art at Exits home page