Location: Yellowstone National Park
It’s always a slow drive through Yellowstone National Park. The roads are narrow and windy and always wall-to-wall with people looking for animals. American bison are one of the big draws. Once, while passing a large herd near the Lamar River, I saw a ranger giving hell to a tourist, and with good reason. The woman insisted on posing for a photograph near a wayward bull that had wandered close to the road. Apparently she missed the warnings about getting gored by these large bovids that appear as docile as cattle but are still wild animals, and their horns can kill you.
Horns, found on bison, bighorn sheep, mountain goats and other bovines, are different than antlers. Though the interior is bone, the exterior is made of keratin that grows from specialized hair follicles similar to human fingernails. Horns begin to grow right after birth and continue to grow throughout an animal’s life, which is a way to tell the age of the animal. Horns grow faster during the spring and summer when food is plentiful, then slow down during the fall and winter, forming a dark ring around the base of each horn. Count the rings and you can tell how old the animal is. I know of two exceptions: the pronghorn, which sheds its horns each year; and the bison whose horn rings are too difficult to differentiate.