The California Department of Fish and Wildlife (CDFW) is partnering with researchers at the University of California, Davis on an innovative multi-year study of tule elk herds in Colusa and Lake counties.
CDFW and UC Davis researchers plan to collect elk pellets and study DNA extracted from the pellets during a two-part study scheduled to begin later this month. While fecal DNA approaches have been used to estimate abundance and other population data in several deer populations in California since 2011, this study will be the first application of the technique on free-ranging tule elk. The effort will help CDFW staff determine the population, distribution, movement and habitat use of tule elk within the study area, and the results will guide conservation planning efforts.
The Cache Creek, Lake Pillsbury, and East Park Reservoir tule elk herds often roam public land, offering viewing and hunting opportunities for the public, and the herds also frequent private land. This presents an opportunity for landowners to aid CDFW’s elk conservation goals by facilitating research activities on their property. Landowners willing to provide access can contact CDFW Wildlife Biologist Josh Bush at (916) 374-9137, or at Joshua.Bush@wildlife.ca.gov.
In the opening phase of the study, biologists will use helicopter net-gunning and ground-based tranquilizer darting to capture and place satellite collars on 56 tule elk in the Cache Creek, Lake Pillsbury, Bear Valley and East Park Reservoir herds. The collars will log GPS coordinates for an elk’s location every 13 hours and the locations will be stored in an online database accessible to CDFW biologists. Collar data will also guide site selection for the second phase of the study, a DNA-based survey to estimate numbers of individuals in the population and measure gene flow among herds. This phase is scheduled to begin in late summer of next year.
DNA profiles will be obtained from elk fecal pellets collected by CDFW and UC Davis personnel. The pellets will be analyzed at the Mammalian Ecology and Conservation Unit of the Veterinary Genetics Laboratory at the UC Davis School of Veterinary Medicine and the DNA used to identify individuals, their sex and familial relationships to other elk.
The use of DNA extracted from fecal pellets to estimate the size of wildlife populations is a recently developed technique that has become more favorable among wildlife researchers over the past decade. This safe, non-invasive approach minimally disturbs animals, enables surveys in low-visibility habitats where sight-based surveys may be relatively ineffective, and can be implemented more frequently than other costlier survey methods.
Tule elk are a native subspecies of elk unique to California. Prior to the arrival of European settlers, they numbered more than half a million statewide. The population rapidly declined in the mid-1800s due to unregulated market hunting and habitat loss. Tule elk dropped to such low numbers that they were once thought to be extinct. In 1875, an estimated two to 10 tule elk were discovered on a ranch near Lake Buena Vista in Kern County. The ranch owner, Henry Miller, is credited with protecting the last remaining tule elk and allowing them to multiply on his property.
Tule elk have since been closely managed. Beginning in the early 1900s, they were captured and relocated to reestablish herds throughout their historical range in California. The Cache Creek herd was established in 1922, and is the oldest free-ranging tule elk herd in the state. The Lake Pillsbury herd was released in 1978 and many of those elk dispersed throughout the Mendocino National Forest and into surrounding areas. By the early 1990s, some settled near Stonyford and established the East Park Reservoir herd. Since 1975, CDFW has captured and relocated more than 1,500 elk and currently it is estimated that there are more than 5,100 tule elk distributed in 22 herds throughout California.
Become a local partner in tule elk conservation by contacting Wildlife Biologist Josh Bush at (916) 374-9137 or Joshua.Bush@wildlife.ca.gov. For more information about tule elk, please visit: www.wildlife.ca.gov/conservation/mammals/elk/tule-elk.