The Dall Sheep (AKA Thinhorn Sheep) of Denali National Park
The five most sought out animals to see in Denali National Park are moose, bears, caribou, wolves, and Dall sheep. Of this group, Dall sheep are probably the most obscure and, at least for me, hardest to conjure up an image of. However, they are also some of the most beautiful and special animals you could see on a trip to the mountains of Alaska. Today, you will learn everything you need to know to fully appreciate these stunning creatures on your next expedition up North.
Dall sheep, otherwise known as thinhorn sheep or ovis dalli dalli, live in the mountain ranges of Alaska and northwestern Canada. The mountainous, rugged terrain is essential to their survival, and they use it to escape predators such as wolves, bears, and golden eagles. For thinhorn sheep, mountaineering is more than a hobby - it’s a lifestyle. Their diet consists of grasses, sedges, and flowers, with some broad leafed plants and dwarf willows that grow in their mountain home. In the winter, when food is scarce, Dall sheep include lichen in food rotation. In the spring, they frequently visit mineral licks, where they can gather essential minerals such as calcium, sodium, iron, phosphorus and zinc from natural deposits.
In the Denali National Park area, Dall sheep are most common on the east and west ends of the park in the high mountains. Many people don’t know that the Denali National Park itself was created to protect these beautiful creatures. It’s easy to look at the Mt. Denali and its staggering size and assume that the park was created to honor the mountain. Despite how obvious that explanation may seem, it’s incorrect. Denali National Park was actually created to protect the thinhorn sheep and other wildlife that inhabited the area.
What makes Dall sheep so striking aside from their agility and relative scarcity is their fur and horns. The fur on these wild sheep is a pure off-white color, consisting of a fine wool undercoat, and longer stiff, hollow guard hairs. Dall sheep are some of the only mountain sheep to have a totally white coat, and it provides excellent camouflage in the snow. The males, called rams, can be differentiated from the females (ewes) by their huge curling horns. Ewes do also have horns, but fully grown they are much shorter, more slender, and less curved. The rams’ horns become distinguishable from ewes’ at around three years old, and Dall sheep horns can actually be used to measure their age. As their horns grow, rings (known as annuli) are added, and by counting these, researchers have found rams as old as sixteen years and ewes as old as nineteen years, though their average lifespan is closer to twelve years.
Dall sheep have a fluctuating, often decreasing population, due to factors such as environment, predators and low birth rate. They are not heavily hunted by humans, but they are occasionally hunted as a subsistence replacement when caribou and moose are not available. The environmental challenge for Dall sheep is primarily due to harsh winter conditions and snowfall covering and taking away food options for the sheep. Dall rams are also typically unsuccessful at breeding until they have reached full size (a little over three feet) and their horns have fully matured (complete circle or curl) which usually takes seven to eight years. Mating season is when you are mostly likely to see the rams crashing heads in classic mountain sheep fashion, but they do occasionally butt heads year round.
I hope that after reading this you have gained some knowledge and respect for this species, and why it is a classic and exciting achievement to spot Dall sheep in Denali National Park. On hiking tours with Northern Epics, you will be sure to learn even more about Dall sheep and the many other animals inhabiting Denali from our expert guides, and with a keen eye you may spot some as well!
