Mule Deer: Home on the (Winter) Range
by Stephen Ingram

The clatter of dueling antlers is barely discernible above the sound of the wind through the pines as two young bucks spar with one another. A group of a dozen does and a few fawns nibble on bitterbrush as other fawns playfully jump around in the invigorating, cold north wind. Six larger four— and five— point bucks nonchalantly amble farther from the road into the protection of the pinyon and Jeffrey pines. It is definitely the season of the mule deer in the lower elevations of the Eastern Sierra.

Mule deer, known by biologists as Odocoileus hemionus, got their common name from explorers Lewis and Clark. In language typical of his day, William Clark wrote on March 11, 1806,

"The Ears and tail of the Animale [sic] when compared with those of the Common [white-tailed] Deer, so well comported with those of the Mule when compared with the Horse, that we have by way of distinction adapted the appellation of the Mule Deer..."

And as expected by the size of their ears, mule deer have a very acute sense of hearing. The Inyo mule deer, which winter in Mono and Inyo counties, are one of six subspecies in California and are most closely related to Rocky Mountain mule deer.

After spending their summer in the forests and meadows of the High Sierra, mule deer migrate downslope through their intermediate range and, when the snow is deep, down further into what is called "critical winter range." Like wildebeest in Africa that follow seasonal rains in search of fresh forage, Inyo mule deer in the Eastern Sierra migrate to survive.

The area from Swall Meadows south to Round Valley, and from the base of Wheeler Crest east to near Rock Creek Gorge, encompasses the winter range of the Round Valley mule deer herd. Three-quarters of the 2,400 animals that comprise this herd migrate through the Swall Meadows/ Sherwin Grade area, according to California Department of Fish & Game (DFG) Wildlife Biologist Vern Bleich. The rest of the herd, the "Buttermilk" group, migrates over Piute Pass and other Bishop Creek passes. The deer that winter in Round Valley migrate through four or five counties, and some may venture as far as Florence Lake at 7,300 feet on the Sierra's west side. Other Round Valley deer summer in the upper San Joaquin and upper Rush Creek drainages, west of June Lake, according to DFG Wildlife Biologist Tim Taylor.

"Round Valley is one of the smallest winter ranges I know of," says Taylor. He cites Dr. Richard Mackie's analogy of a wheel for mule deer habitat, noting that the outer part or rim of the wheel is analogous to their broad summer range, the spokes are the migratory paths they use, and the small, central hub is the winter range of mule deer, the most important component of their habitat. "What happens on the winter range in terms of habitat loss will affect how deer use other seasonal ranges," says Taylor.

Living with Wildlife

What can residents of rural areas do to reduce their impacts on native wildlife? Here are some practical suggestions:

• Minimize clearing of native vegetation beyond the fire-safe distance from your house. Deer, other mammals, birds and insects all rely on native plants for food and cover.
• Avoid use of chemicals in your garden or on native vegetation. Pesticides kill beneficial insects and herbicides can be ingested by feeding animals.
• Minimize outdoor lighting. Deer and other wildlife usually avoid artificial lights.
• Ensure that your pets do not chase deer or harass other wildlife; this will cause stress and can lead to injury.
• Avoid feeding deer because this can draw predators to their habitual feeding sites.