Barren Ground Caribou

This is the barren ground caribou (Rangifer tarandus groenlandicus), one of seven subspecies of caribou and the largest by weight and height. Adult males or bulls can be over 1.2 m (4 ft) and weigh 160 kg (350 lb). Their antlers may be 1.5 m (5 ft) across.

Deer (which includes caribou) antlers are completely different from the hollow, permanent horns of other ruminants. Antlers are shed and regenerated annually, their growth controlled by sex hormones. In the spring, antlers have a velvet appearance due to the thin coat of fine hairs that supplies them with nourishing blood flow. Within a few months, antler growth is complete and blood circulation in the velvet ceases. The deer rubs its antlers against a tree to scrape away the dead skin. The caribou, Rangifer tarandus, is the only deer species in which females grow antlers.

Lon E. Lauber/Oxford Scientific Films

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Caribou

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