Bison Rutting Season…

In Yellowstone National Park the bison are about to begin their rutting season in earnest. Unfortunately, we will have to miss the rut, but I do have some photos of bison during the period leading up to the rut that I can share.

In this series a mature bull is checking out a cow to see if she is receptive to mating. I have seen this behavior among deer, antelope and elk, as well as bison. The lip curl is called “flehmen” (noun Animal Behavior. a behavioral response of many male mammals, esp. deer, antelope, and other artiodactyls, consisting of lip curling and head raising after sniffing a female's urine)…

Here a young bull playfully challenges a patriarch to spar with him. The old bull looks on showing little interest in the young one. Perhaps he is remembering his own youth and being full of vigor…

In this photo a bull is strengthening his neck and shoulder muscles by rubbing against a tree…

These young bulls are sparring to test each other’s strength and skill. They are too young to participate in the in the serious fighting that takes place by the mature bulls during the rut…