Unlike the White-tailed Deer, he Mule Deer (Odocoileus Hemionus), named for its large, mule-like ears, avoids areas of human activity. On summer evenings single individuals or groups of Mule Deer can be seen near forest edges in western parks. In winter, large, loosely structured herds assemble on brushy slopes in the foothills where browse (the twigs and buds of woody plants) is available. The animals move to higher elevations in spring.
Mule deer inhabits western North America from southeast Alaska and northwest Saskatchewan to the Dakotas, west Texas, northwest Mexico and Baja California.
Mule deer are stockier and more barrel chested than closely related whitetail deer. Antlers of mule deer are dichotomously branched, which means the main beam splits into two equal branches and each of these branches again to form points (tines). They have shorter tails that they do not elevate ("flag") when they run.
Like other deer, this psecies ruts in autumn, when males contest for and associate briefly with females. Spotted fawns, usually twins, are born in spring and weaned at about six weeks of age. Young females may stay with their mother for two years, but males leave in their first year.
Mule deer have an unsual stiff-legged bounding gait called stotting. It is fascinating to watch them as all four legs leave and hit the ground at the same time. Although they are not as graceful as whitetails, for short distances mule deer can reach top speeds of 25 miles per hour with boucing leaps 15 feet long. The largest males (bucks) are in the Rocky Mountains.