Rocky Mountain Bighorn Sheep is Colorado’s official mammal. In addition, Colorado is home to more Bighorn sheep than anywhere else in the world. Male bighorns are called rams and females are called ewes. They are diurnal (i.e., active during the daytime) and have exceptional eyesight, hearing, and sense of smell. In addition, they have pliable, agile hooves that facilitate climbs up steep rock faces where predators are unable to follow. In the winter, Bighorn sheep grow a second layer of hair to protect them from harsh conditions.
Their horns are not like antlers because they do not shed them. Instead, a ram’s horns continue to grow in size (i.e., up to 30 lbs) and shape (i.e., into a full circular curl) and, specifically, become an indication of the sheep’s sex and age. In addition, rams use their horns in mating battles that include horn collisions at speeds of up to 40 mph. A ewe’s horns grow until the age of four, to about 8-10 inches in length and do not form a full circular curl.
They graze at low elevations in the late spring and summer and at higher elevations during fall and winter. Specifically, they eat flowering plants, grasses, and shrubs that grow on various terrains such as meadows, alpine tundra, and open woodland. Rams can grow to be six feet long, three feet tall, and weigh up to 250 lbs. On the other hand, ewes are slightly smaller maxing out at about 200 lbs.
Most wildlife problems are caused by humans leaving food or trash that animals like the Bighorn sheep end up eating. Thus, it is important to leave no trace of your visits to wildlife areas.
The following picture was taken in early autumn on US-34 between Fort Collins and Estes Park. By my estimates, the two Bighorn sheep in the picture are ewes because rams have bigger, more rounded horns.