"Nature: the constant battle between species to see who's on top of the pecking order." October 6, 2017 Grand Teton National Park Wyoming The relationship between the American Bison and the Cowbird is an example of commensalism. This is different from a symbiotic relationship due to the fact that only one organism, in this case the cowbird, benefits from the relationship. The birds eat the insects stirred up by the giant mammals, with the bison being left without benefit from the feathered flyers.