The breeding season, or rut, for the tule elk of the San Luis NWR has come to an end, but the rut for the refuge’s black-tailed deer is just getting started and typically lasts through November.
During the season, deer are more active as bucks roam about in pursuit of does and get into sparring matches with other bucks. This time of year bucks will also engage in other typical rut behaviors like scraping the ground to mark their territory and rubbing their antlers on trees to remove the velvet from them. The next few weeks can be a good time to catch sight of deer on the wildlife refuge. Early morning is the best time of day, in general, for wildlife watching. Late afternoon to early evening can also be a good time to watch wildlife as it does what it does.
The tule elk and black-tailed deer of the San Joaquin Valley are all that is left of the great migrating herds of ungulates that once called California home. Massive herds of wildebeest, zebra, and gazelles moving seasonally across the grasslands and plains of the Serengeti in Tanzania and the Maasai Mara game preserve in Kenya (Africa) are most well-known but California once had its own great herds of seasonally migrating ungulates – tule elk, black-tailed deer, and pronghorn.
The Golden State’s historic herds rivaled African ones in size. Black-tailed deer are believed to have numbered nearly two million or more animals, while tule elk and pronghorn each numbered about 500,000.
Tule elk are endemic to California and once roamed throughout the Great Central Valley from Shasta County in the north to the Tehachapi Mountains in the south. They also moved through the passes to inhabit the coastal valleys and foothills of the Sierra Nevada range.
Smaller herds of between 50 and 100 animals moved around more regionally based on the availability of food and water. Their movements were also determined by the seasonal flooding of the Sacramento and San Joaquin Rivers.
The black-tailed deer (Odocoileus hemionus columbianus) is a subspecies of the mule deer, a larger inland species found east of the Cascade and Sierra Nevada mountain ranges. The black-tailed deer is smaller and inhabits the Pacific coast and areas west of the aforementioned mountain ranges from San Luis Obispo County north to Alaska. The primary feature distinguishing them from their larger cousins is their entirely black tail.
The pronghorn is a species found only in North America and was once considered to be California’s most numerous big game animal, inhabiting much of the state except for the coastal areas and highest mountain ranges. Today, nearly all of California’s pronghorn are found in the extreme northeastern sagebrush region of the state.
Pronghorn are often referred to as “pronghorn antelope,” but they are not antelope at all. Pronghorn are North American while true antelope are native to Africa and Asia. The pronghorn is also the sole surviving member of its family, Antilocapridae, while true antelope encompass numerous species within the family, Bovidae.
A key distinguishing feature between pronghorn and antelope is their horns. Pronghorn shed them annually, like the tule elk and black-tailed deer shed their antlers. Pronghorn horns have a permanent boney core with an outer sheath comprised of keratin, like fingernails, which shed annually. True antelope keep their horns for life.
Today’s populations of tule elk, black-tailed deer, and pronghorn are greatly reduced from their historic numbers. All three species were significantly impacted by the rise in market hunting during the California Gold Rush in the mid-1800s, the competition for food by multiple millions of head of cattle and sheep introduced into California’s grasslands, and the loss of habitat from the conversion of grasslands to agricultural and urban development.
Visitors the San Luis NWR won’t be able to see pronghorn, but they can observe the other two remnants of California’s great migrating herds. To see the tule elk, drive the 5-mile Tule Elk Auto Tour Route. Black-tailed deer can be seen all over the wildlife refuge from both the Tule Elk route and the Waterfowl Auto Tour Route.
