Dall sheep

LIFE SPAN: 15 years in captivity.

RANGE: This sheep species is found at high elevations in mountain ranges throughout Alaska. Their ancestral habitat is the Tanana-Yukon uplands, which now has fewer than 1,000 sheep.

SIZE: Rams (males) weigh up to 300 pounds; ewes (females) are closer to 150 pounds.

PHYSICAL FEATURES: Both rams and ewes have horns. The horns of the rams in particular are the largest of all ruminants in relation to their body size. Yearling rams have smaller, straight horns that look similar to adult ewes. Only mature rams have massive curling horns—used as a symbol of rank. Their horns grow throughout their lives, with growth stopping each winter. This creates rings (annuli) which can be used to indicate age.

FOOD: Herbivores. Dall sheep eat grasses and sedges. Their winter diet is limited to frozen grass and sedge stems. Some eat significant amounts of lichen and moss during winter. Their digestive system is adapted to utilize low quality food during winter and during food shortages.

BEHAVIOR: Unlike mountain goats, which are methodical climbers, Dall sheep jump through rugged cliffs to escape danger and are capable of running very fast for short distances.

CONSERVATION: The remoteness of their habitat is a good buffer from humans, but the use of alpine areas might cause problems in future. Population growth is slower due to low birth rates (sometimes every other year), high predation and difficult terrain. These are continuous pressures they face.

PLANT NOTES: Dall sheep eat a variety of plants and berries during summer months. Species include horsetail ferns, willow, fireweed, cranberries and grasses. Their winter diets consists of lichens, mosses and frozen grass. Food availability is a limiting factor, especially when deep snow or thick ice cover their range. Many sheep starve during winters where plants are inaccessible.

NOTE ABOUT DALL SHEEP: Many people do not realize the role Dall sheep played in the establishment of Denali National Park, long before Alaska was even a state. To learn more about this history of a species inspiring change, click here.