Deer is the family; reindeer is one species within it. What distinguishes reindeer is that both sexes grow antlers — unique among deer — and that they are adapted to the Arctic. In North America the same animal is called caribou, with reindeer usually reserved for the domesticated herds of northern Europe and Asia.
The core difference
- deer — the family Cervidae: red deer, roe deer, white-tailed deer, elk, moose and many more.
- reindeer — one species, Rangifer tarandus, native to the Arctic and subarctic.
What makes reindeer distinctive
- Both sexes grow antlers. In every other deer species antlers are male-only. Males shed theirs in early winter while females keep theirs until spring — which is the basis of the observation that Christmas sleigh teams depicted with antlers are likely female.
- Hooves change with the season, softening in summer and hardening in winter for ice and digging through snow.
- They are the only deer to have been widely domesticated, herded across northern Scandinavia and Siberia for meat, milk, hides and transport.
Reindeer and caribou
The same species. Reindeer is generally used for Eurasian and domesticated animals, caribou for the wild North American ones. Both words describe Rangifer tarandus, so the difference is regional and cultural rather than biological.
The plural trap
Deer is unchanged in the plural — one deer, five deer — and so is reindeer. Deers and reindeers are not standard. The same pattern governs sheep, fish and moose.
Elk, which means two different animals
Worth knowing because it compounds the confusion: in Europe elk means the animal North Americans call a moose. In North America elk means a different, smaller species, also called wapiti. Same word, two animals, depending on which side of the Atlantic you are on.
Frequently asked questions
Is a reindeer a deer?
Yes. Reindeer is one species within the deer family, distinguished by both sexes growing antlers and by its Arctic adaptations.
Are reindeer and caribou the same animal?
Yes — both are Rangifer tarandus. Reindeer usually refers to Eurasian and domesticated animals, caribou to wild North American ones.
Is "reindeers" correct?
No. Both deer and reindeer are unchanged in the plural, like sheep and fish.