By Olivia Lappin
UC Cooperative Extension Modoc
Having grown up in Maine and spending my entire life there, (a whopping 23 years) I was always drawn to the West. Seeing elk, bison, and wild horses was at the top of my to-do list, so when presented with the opportunity to study wild horse and elk interactions here in Modoc County, I was ecstatic! It may have been a long road trip from East to West Coast to work for only a couple of months, but who could pass up such an amazing opportunity? I have grown quite a soft spot for this place, especially for the people and wildlife that are here (particularly the elk!).
California is home to three sub-species of elk: Roosevelt, Tule, and Rocky Mountain. As European settlement spanned across the United States, many wildlife species were decimated, including elk, as a result of the fur/hide market, meat trades, introduction of non-native plants, and competition with domestic cattle/horses. Due to low population numbers, translocation of Rocky Mountain elk from Yellowstone National Park to Shasta County and the Pit River occurred prior to 1970. Following their translocation, sightings of Rocky Mountain elk here in Modoc County were being reported in the early 1990s, which led to the use of radio telemetry to monitor their distribution and movement during 1993 and 1994. Since then, it has been documented that Rocky Mountain elk are expanding their range into other parts of Modoc County along with sections of Plumas, Sierra, Shasta, Lassen and Siskiyou counties. Currently, California Department of Fish and Wildlife (CDFW) is working to expand their knowledge on elk distribution and movement by tracking them through the use of radio collars throughout northern California.
Situated in Modoc County, the Devil’s Garden Plateau (roughly 500,000 acres of Forest Service, BLM and private land) is occupied by the Rocky Mountain elk species. In addition to the elk, the Devil’s Garden is home to mule deer, pronghorn antelope, bobcat, mountain lion, coyote, a myriad of avian species and approximately 2,000 wild horses.
For rangeland specialists, land managers, ranchers, and biologists, wild horses have created an array of management challenges. These horses have been present on the Devil’s Garden for about 140 years and they have significantly exceeded the appropriate management level (204-402 horses set in 2013). Additionally, horses have expanded past territory boundaries and on to surrounding private and tribal lands.
The increase in wild horse population numbers has generated concern about limited resources, particularly water. With increasing wild horse populations, there is a cause for concern that there will be a resulting increase in competition for these limited resources, which could lead to severe consequences for other species that reside in the territory, such as elk. A handful of studies have already documented the negative impacts that wild horses can have on native flora and fauna, especially on sage-steppe ecosystems like that of Devil’s Garden. Previous studies have also shown that wild horses have negative interactions with other species that they share the land with such as cattle, mule deer, and elk by deterring them away from water.
Research looking at interactions between wild horses and elk has not yet been conducted in the Devil’s Garden Plateau and we are hoping to gain valuable information that can be used to inform future management decisions that could potentially help to properly manage elk populations at sustainable levels.
To carry out our study, we distributed 15 game cameras throughout the Devil’s Garden with help from CDFW biologist Erin Nigon. Three cameras were placed at sites that are horse exclusive (no elk use) and four cameras were placed at sites that are elk exclusive (no horse use). The last eight cameras were placed in areas with both horse and elk use in hopes to capture interaction between the two species on camera.
We have already begun looking through some of our camera data and have captured elk use at some of our sites. We are excited to see what else we are able to capture on camera in the next few months. Keep an eye out on our blog and Facebook page for updates on the study.
For more information about elk and horses:
https://nrm.dfg.ca.gov/FileHandler.ashx?DocumentID=162912&inline (2018 California Elk Management Plan)
file:///Users/olivialappin/Downloads/Dominance_of_a_natural_water_s.PDF (Previous study looking at elk and wild horse interactions in Colorado)
https://www.fs.usda.gov/detail/modoc/landmanagement/resourcemanagement/?cid=fseprd594040 (Devil’s Garden Horses)