Reindeer Facts: Antlers, Migration & Habitat

Reindeer, also called caribou in North America, are the only deer species in which both males and females grow antlers. These remarkable animals undertake some of the longest migrations of any land mammal and thrive in the harshest environments on Earth.

Why Female Reindeer Keep Their Antlers Longer

Unlike other deer species, female reindeer grow antlers alongside males. Males shed their antlers in late fall after mating season, but females keep theirs through winter until spring calving. This means Santa's sleigh pullers, depicted with antlers at Christmas, would actually be female. The antlers help pregnant females defend feeding spots in deep snow during winter.

The Longest Land Migration on Earth

Some reindeer herds migrate up to 3,000 miles annually, the longest migration of any land mammal. The Porcupine caribou herd travels between Alaska and Canada, moving in groups of up to 500,000 animals. This massive journey helps them find food across seasons and escape biting insects during summer.

Clicking Hooves That Sound Like Footsteps

Reindeer hooves make distinctive clicking sounds when they walk. A tendon in their feet slips over a bone with each step, creating an audible click. Scientists believe this clicking helps reindeer stay together in blizzards when visibility drops to zero. The sound guides separated herd members back to the group.

Built to Survive Arctic Winters

Reindeer can survive temperatures as low as negative 70°F. Their fur has two layers including hollow guard hairs that trap air for insulation. Their noses warm frigid air before it reaches their lungs, and their legs stay cold to minimize heat loss. Even their hooves adapt, shrinking in summer for soft ground and expanding in winter for snow travel.

What Reindeer Eat to Survive Winter

In winter, reindeer dig through snow to find lichen, their primary food source. A single reindeer can consume 9 to 18 pounds of vegetation daily. Their specialized digestive system extracts maximum nutrition from sparse Arctic plants. During summer, they feast on grasses, leaves, and mushrooms to build fat reserves.

Eyes That Change Color With Seasons

Reindeer eyes change from gold in summer to blue in winter. This remarkable adaptation helps them see in extreme Arctic light conditions. The color change increases light sensitivity during dark winter months when the sun barely rises. It makes reindeer the only mammals known to change eye color seasonally.