Study Areas and Populations--Madison-Firehole Site

The Madison-Firehole (MF) site covers 269 km², entirely within YNP, with grassy meadows and sagebrush grassland in valley bottoms and coniferous forest on the slopes above. Elevation runs from 2150 m ASL to 2800 m ASL. The site typically has a heavy snowpack (23 cm snow water equivalent), and prior to colonization by wolves, deaths by starvation during hard winters were common for young and old elk. Bob Garrott has worked on MF elk for 10 years, gathering 7 years of population and demographic data prior to the arrival of wolves, and 3 years after the arrival of wolves. Garrott's demographic data come from both uncollared and radiocollared individuals, with 35-55 functioning transmitters. He has also collected data on wolf activity, prey selection and predation rates for the past three years.

Unlike the other study areas, the MF elk population is nonmigratory. Because the MF herd remains within YNP year-round, it is not exposed to human hunting. Over the past 30 years, the herd has varied from 400 to 800 animals, currently holding about 650 elk in late fall (2.42 elk/km²). Bison (Bison bison) numbers can be high in winter (up to ~1200 individuals, depending on altitudinal migration), but to date they are rarely killed by wolves (Jaffe 2001). The MF site is used primarily by the Nez Perce pack, which numbered 22 wolves in the winter of 2000/01. The Chief Joseph pack occasional uses this area and a new pack, Cougar, became established along the western boundary of the study area in spring 2001. Over the past three winters, wolf-days have averaged 902, with an average of 54.5 kills (6.04 kills/100 wolf-days). With respect to major variables that may affect wolf-elk predation, this site combines public land, the absence of human hunting, intermittent use by wolves, very heavy snow and a nonmigratory elk herd at low (and stable) density, with moderate group sizes (Group sizes averaging 6-10).

Research Projects in the Madison-Firehole Site:

--Winter wolf predation in an elk-bison system in Yellowstone National Park--Rosemary Jaffe, M.S. 2001

--Spatial dynamics of recolonizing wolves in Madison-Firehole region of Yellowstone National Park--Eric Bergman, M.S. 2003

--Identifying large herbivore distribution mechanisms through application of fine scale snow modeling--Adam Messer, M.S. 2003

--Applying Predator-Prey Theory to Large Mammal Systems: Predation Rates and Prey Selection of Wolves in Greater Yellowstone--Matthew Becker, Ph.D. Candidate