Dall sheep are the northernmost wild sheep in the world. The age of the sheep can be calculated from the number of growth rings on their horns. Dall sheep spend most of their lives on the jagged slopes of mountains. Their cloven hooves with rough pads help them cling to cliff edges and broken ledges, where they flock to elude predators.
Male Dall sheep are called rams and are distinguished by their massive curling horns which take up to 8 years to grow and are composed of keratin, the same material as our fingernails. The head butting that rams are known for is the way males establish their reproductive rank. These clashes occur intermittently throughout the year but are most dramatic during the rut when rams compete with each other to mate with female sheep called ewes.