The Mule Deer is a deer whose habitat is in the western half of North America. It gets its name from its large mule-like ears. Its closest relative is the Black-tailed Deer. The two species often share natural habitats, and can be mistaken for one another. The most noticeable differences between the two is the color of their tails, and their antlers. The Mule Deer's tail is black tipped. Mule Deer antlers "fork" as they grow rather than growing and expanding forward. Each year a buck's antlers start to grow in spring and are shed after mating season from mid-January to mid-April. Mule bucks also tend to grow somewhat larger than their white-tailed counterparts, particularly in cold climates, and have somewhat more prominent ears.
Instead of running, Mule Deer move with a bounding leap (stotting) with all four feet coming down together.
References: