While calves often appear annoyed or surprised when little hitchhikers land on their backs, adult Bison (such as the large bull in the photo, above) seem hardly to notice them at all. I’ve seen Bison transporting a half dozen or more birds on their backs—mostly brown-headed cowbirds—as they lumber across Yellowstone or Teton meadows.
But the birds don’t maintain their perches for very long. They’re more interested in the insects and seeds Bison shake loose as they travel through the tall grasses teeming with both. It’s a free ride the birds have been enjoying for tens of thousands (possibly hundreds of thousands) of years. Though I’m not entirely clear how the Bison prosper from the relationship.
To see more photos of the Bison and other wildlife I encountered on my visit to Yellowstone and the Tetons this fall, visit this gallery of images from the trip. You’ll also find some more of the landscape photos I created. Enjoy.