Morphological variation in Odocoileus

The main beams of the antlers of mule- & black-tailed deer (O. hemionus, above left) are branched , whereas the antlers of white-tailed deer (O. virginianus, above right) have an unbranched. Mule- & black-tailed deer have a relatively narrow tail with a black tip (below, left), whereas white-tails have a broad tail with a white fringe (below, right). Mule & black-tailed deer typically carry their tails down when running: white-tails carry their tails raised, with the white undersurface showing.