Buffalo begin their annual (and loud) ritual of rutting in Yellowstone National Park every year when the temperature begins to fall over night. They strut around the Lamar River valley and other corners of the park looking for someone to 'go ahead and make their day'. The bulls snort, the pee a lot, and they cover themselves by rolling in the dirt. And their female counterparts don't seem much to care. In any case, it really is quite a sight to behold.
Below is a recording I made of the buffalo rutting in the Lamar River valley during my recent visit to Yellowstone National Park. I hope you enjoy: