Family: Bovidae, Cattle, Goats, and Sheep view all from this family
Description A small bovid. White above and below, often with yellowish or brownish cast; hooves yellowish brown. Horns of ram massive, light yellow, with well-defined growth rings flaring out and away from head; about 3' (90 cm) long, with 4'1" (1.25 m) the largest recorded size; horn spread to 3' (90 cm). Ewe's slender spikes less than 15" (38 cm) long. In southernmost part of range, black phase individuals, known as "Stone Sheep," vary from charcoal gray verging on black to light gray or gray brown; in Yukon, where Dall's and Stone phases intergrade, gray phase individuals are usually darker on back, occasionally with dark "saddle"; these sheep have white belly, rump patch, back of legs, and facial blaze; dark hooves; and are often slightly bigger than Dall's Sheep, with slightly heavier horns. Ht male 33-41" (83-105 cm), female 30-36" (75-90 cm); L male 4'5"-5' (1.34-1.53 m), female 3'5"-4'5" (1.05-1.35 m); T male 3 1/2-4 1/2" (8.9-11.5 cm), female 3-3 1/2" (7.5-9 cm); HF 15-20" (38-51 cm); Wt male 174-200 lb (79-91 kg), female 100-125 lb (45-57 kg).
Similar Species Bighorn Sheep is brown, has larger, thicker horns, and occurs to the south.
Breeding Breeds late fall; after gestation of slightly less than 6 months, 1 (rarely 2) young born mid-May.
Habitat Rocky, mountainous areas.
Range Disjunct populations in Alaska, Yukon, w Mackenzie district (Northwest Territories), and n British Columbia.
Discussion Dall's Sheep is diurnal. Its habits are similar to those of the Bighorn Sheep, but it seems more wary and agile. In winter, the entire herd feeds together on such woody plants as willow, sage, crowberry, and cranberry. In summer, the animal grazes on grasses, sedges, and forbs. Staple foods are fescue and sedges, particularly the seed heads. Willow, horseweed, and alpine fireweed are also eaten, and horsetail and Richardson's saxifrage are highly relished. Dall's Sheep seldom eats lichens and mosses. In spring, the herd splits into two groups, with ewes, lambs, and yearling rams in one group, older rams in the other, though older rams sometimes remain solitary; the oldest member in each group is its leader. In late fall, when rams try to gather a harem of ewes, butting contests among rivals are common. After walking apart 15 to 20 yards (14-18 m), rams turn, rise up on their hindfeet, then drop to all fours and race toward each other. The clash of their horns can be heard more than a mile away. Collisions may be repeated, but ultimately the contest becomes a matter of pushing and shoving, until the stronger, heavier ram drives off the weaker one. The newborn lamb walks when three to four hours old, and begins eating grasses at about 10 days. Life span is up to 15 years. Wolves are the chief predators; occasionally a Lynx, Wolverine, Mountain Lion, or bear takes a sheep, and the golden eagle sometimes seizes a lamb.
