First identified and named (for its conspicuous set of ears) by members of the Lewis and Clark party, the mule deer (Odocoileus hemionus) is the rugged western cousin of the more abundant and widespread eastern whitetail. Ranging from the western plains throughout the Rocky Mountain states and to the Pacific coast, the mule deer sports a slightly more muscular profile than the whitetail and may attain a live weight of more than 400 pounds. –JACK LARSON
1 EYES Side-mounted eyes provide the mule deer with a near panoramic field of vision but very poor depth perception. The mule deer’s sensitivity to the ultraviolet light spectrum, which prevails during the low-light hours of early morning and evening, coincides with its crepuscular foraging habits.
2 ANTLERS Unlike the main-beam-with-tines antler configuration of the whitetail buck, the mule deer sports main beams that branch out symmetrically into high tines. A typical mature buck will have 4 points on a side. An exceptionally large rack will carry a spread up to 4 feet wide with a total of 12 points or more.
3 EARS The animal’s poor visual depth perception is offset by the acute hearing its oversize ears provide. (The animal also got its name from its ears, which are so large they resemble a mule’s.) It is thought that the muley’s superb sense of hearing is sensitive enough to discern from what distance a slight sound was made.
4 LEGS The muley employs a bounding, goatlike stride in which it jumps high into the air and all four feet alight simultaneously. Called stotting, this peculiar gait allows the deer to ascend steep mountainsides with remarkable ease, attain speeds of up to 35 mph on flat land, and clear fences and obstructions up to 8 feet high.
5 HOOVES Despite the diminutive size of its hooves, the mule deer is a capable swimmer, though it rarely uses this ability to escape predators.
6 TAIL/RUMP Though the mule deer possesses a white rump patch similar to the whitetail’s, it does not raise its tail in alarm when fleeing danger.