Dall Sheep Fact Sheet
A Sheep of a
Different Color: Dall
sheep are typically all white in color, although a few black hairs on
the tail are not uncommon. The white coat is an adaptation, or
special trait that helps them survive. Dall sheep typically move to
lower altitudes in the winter, but predators are more numerous there.
The white coat helps the sheep go unseen against the snow by predators.
In the summer months, their coat does not change color, but stays white.
They are still protected, however, because they move to steep and rocky
cliffs where predators are hard-pressed to follow.
Both rams (males) and ewes
(females) have horns which continue to grow throughout the animals’
lives. Horns are different from antlers because horns are a
slow-growing, permanent bone, covered by a thin sheath of hard, bony
keratin. The entire horn (core and sheath) are never shed or “dropped”
like antlers. Horns are usually not branched, but have massive bases and
taper to fine tips. Ram horns grow continually in a spiral, but growth
slows down during winter. The annual decrease of horn growth results in
a pattern of rings along the horn called annual rings. A sheep's age can
be determined by counting these rings. Female horns are shorter,
blunter, and grow in a gentle arc over the head. They also have annual
rings. Rams frequently use their horns to fight during the breeding
All ungulates walk on hoofed
toes. Hooves are made of keratin, which encases the toe bones. Dall
sheep walk on two toes which places them in the “even-toed” group of
ungulates similar to giraffes, deer, and camels. Hooves are another
adaptation that enable Dall sheep to live on rocky, steep terrain. Their
toes are flexible and able to adjust to the uneven surfaces in their
mountain habitats where sure footing is essential.
Ungulates love to EAT! Dall
sheep feed primarily on grasses and sedges. In the winter they actually
eat frozen grass, stems, lichen, and moss. Sheep will often travel to
mineral licks to eat soil. These are typically rocky outcrops where high
concentrations of minerals are pooled. This replenishes essential
minerals that the sheep cannot get from their daily diet of plants.
Since they eat a variety of
plants, sheep have developed special adaptations for their eating
habits. They have lost their canine teeth but have developed large, flat
cheek teeth with raised ridges. When chewing, the teeth move
side-to-side and front-to-back in a triangular motion to grind food.
Strong lips and tongue are designed to grab and tear foliage and other
vegetation. Special stomach chambers allow ungulates to digest plant
material. Ruminants, such as Dall sheep, have a complex stomach made up
of four chambers. One chamber has bacteria that ferments the food and
breaks down the plant material for absorption. After the food is
fermented, the sheep regurgitates it and chews the food again. This
second chewing is called rumination. After the second chewing, the food
goes through the other three chambers and then to the intestines. It may
take FOUR days to digest a meal completely!
Like other ungulates, Dall
sheep have well-developed senses. Their long noses are filled with
olfactory nerves to help them detect predators. Large ears can rotate to
detect sounds from all directions. Big eyes, set on the sides of their
heads let them see in many directions at the same time.
Loyalty and Safety:
Dall sheep have well developed
social systems. Adult rams live in bands, or groups, associated with ewe
groups during the mating season. Since Dall sheep are very loyal to
their social group, they have very specific home ranges (a geographic
area where they normally live). After joining a social group, sheep are
never known to leave it. One adaptation of living in a social group is
safety from predators. With so many eyes watching for a sign of danger,
a predator can be spotted sooner so the whole group can flee.