American Bison (Bison bison)
Below: Note the Brown-headed Cowbird. It is believed that following the original buffalo herds (to feed on the animals' parasites)
necessitated that the cowbird become a brood parasite. Constantly moving across the plains,
the birds adapted to let other birds raise their young.
A distant herd along the Yellowstone River
Photographed at various locations in Yellowstone NP, Wyoming (6/23-24/2005).