Ecology of a colonizing population of Rocky Mountain elk (Cervus elaphus)

Abstract

Scope and Method of Study: After reintroduction into the Wichita Mountains Wildlife Refuge (WMWR) in the early 1900s, Rocky Mountain elk (Cervus elaphus) established a viable population on private lands. The objectives of this study were to document home range, habitat use, and nutrition of elk on private lands surrounding WMWR. These data will provide a better understanding of the factors affecting population persistence on private lands.

Findings and Conclusions: Twenty-one radiocollared females and 1 radiocollared male were tracked, resulting in 2,657 radiolocations of marked elk from January 2002 to March 2005. Mean annual and seasonal home-range size of elk in forested habitat near WMWR (Granite Area) was smaller than home-range size of elk in a more open grassland habitat (Slick Hills). Elk in the Granite Area and Slick Hills used agricultural fields during forage-limited winter months (Dec-Mar); such fields were not available to elk in WMWR. Hoof, muscle, and fecal stable isotopes of carbon and nitrogen were evaluated from elk on private lands and WMWR. Carbon and nitrogen isotopes suggested that elk on private lands consumed more C3 vegetation with greater nitrogen content on an annual basis compared with elk on WMWR. Agricultural crops provided alternate food resources of better quality to elk on private lands during periods of low natural forage availability (i.e., late summer, winter) compared with elk on WMWR.