Dall sheep
A snowy-white wild sheep of Alaska's steepest ridges, where ewes raise lambs on cliffs and rams carry horns that curl a full circle.
Dall sheep at a glance
Ovis dalli Dall sheep is DAWL sheep, rhymes with hall; Ovis dalli is OH-viss DAHL-ee
- Type
- Mammal · sheep
- Diet
- Herbivore
- Size
- A big ram weighs about as much as a kitchen refrigerator (up to roughly 300 pounds) and stands about as tall at the shoulder as a kitchen counter. Ewes run about half the ram's weight.
- Lifespan
- A 12-year-old is very old; researchers have recorded rams to 16 years and ewes to 19.
- Conservation
- Healthy and not at risk; a legally hunted game species in Alaska
Eats grasses, sedges, lichen, moss
In summer a Dall sheep grazes a wide menu of mountain plants. When snow buries the range, its diet shrinks to dry frozen grass and sedge stems, with lichen and moss for some herds. In spring it hikes, often many miles, to eat mineral-rich soil at a lick.
Should you worry?
Dall sheep are shy and would rather climb than fight, but they are wild and a ram's horns are heavy. The real danger is the cliff: sheep are safe on it and people are not. Stay at least 25 yards back, watch through binoculars, never crowd a ewe with a lamb, never feed them, and never follow one onto steep rock.
The white dots on the dark cliff are easy to write off as patches of last winter’s snow. Then the patch moves, uphill, where the wall goes from steep to near-vertical, and a second dot follows. Those are Dall sheep, and the reason they are on the scariest-looking slope in sight is that the slope is the safest place they know. It is what biologists call escape terrain: wolves, coyotes, brown bears, and wolverines can all climb, but a sheep on a vertical face is at home in a way no wolf is, so the sheep stay where danger cannot follow.
The horns tell the second story. A ram’s horns curl and keep growing his whole life, laying down one growth ring per year, so a naturalist with binoculars can read a sheep’s age the way you read a tree stump. A full circular curl represents seven or eight years of summers and winters on the same ridge. Ewes carry the same white wool and much smaller, shorter horns, and every late spring a ewe heads for the roughest, most broken ground she can find, because lambs are born there in late May and early June and learn to work steep rock within days.
Come summer, watch them from the road and leave the cliff to the sheep. Wrangell-St. Elias holds roughly 13,000 of them, one of the largest concentrations in the world, and Denali road buses pass them most clear days. The white dots are what you will see; the reasons above the dots will be what you tell the kids about later.
Did you know?
- A Dall sheep ram's horns grow one ring per year, like tree rings, so scientists can read a sheep's age from its horns, and a full circular curl takes about 7 to 8 years of growth.
- Lambs are born in late May to early June on the most rugged cliffs a ewe can find, and learn to travel steep rock within days of birth.
- In winter Dall sheep survive on frozen grass and sedge stems, then walk miles in spring to eat mineral-rich dirt at licks.
Common questions
Are Dall sheep dangerous to kids?
Not really. They are shy and escape by climbing. The danger is the cliff, not the sheep. Give them at least 25 yards, watch through binoculars, and never follow one onto steep rock where they are safe and you are not.
What's the difference between a Dall sheep and a bighorn sheep?
Coat color and country. Dall sheep are snowy white and live in Alaska and northwestern Canada; bighorns are brown to tan and live in the Rockies and the southwest. Both are wild cliff sheep.
Why do Dall sheep live on cliffs?
Because steep, broken rock is their refuge, what biologists call escape terrain. Wolves, coyotes, brown bears, and wolverines can climb, but a sheep on a near-vertical face is on home ground, so the sheep stay where danger cannot follow.