Figure 1.

(a) Radio-tracking data for five contiguous packs in the Lamar Valley region of Yellowstone National Park (R. L. Crabtree et al. unpublished). Black contour lines show topographic relief in metres. Coloured points (filled circles) indicate relocations for individuals belonging to the Bison (red), Druid (green), Fossil Forest (blue), Norris (light-blue) and Soda Butte (pink) packs collected during the period 1990–1994 prior to wolf re-introduction. Filled triangles indicate the denning areas for each pack used in the model fitting as their home range centre. (b) Coloured contour lines showing fit of the CA home range model (equations (2.1) and (2.2)) to relocation data (filled circles) for the five groups in Lamar Valley. Black contour lines show topographic relief in metres. Coloured contour lines show the probability density function u⁽ⁱ⁾(x, y) for each pack (i=1, …, 5), in density units scaled so that both the domain area A and integral of u⁽ⁱ⁾(x, y) are unity. The home range centres for each pack are shown (filled triangles). Maximum-likelihood values, AIC scores and estimates for β and m are given in table 1. (c) Small mammal prey availability in the Lamar Valley region of Yellowstone National Park. Shading indicates small mammal biomass density in kg ha⁻¹ calculated using estimates of small mammal biomass density for different habitat types, and mapped onto the region using the Park Service Geographic Information System. Details on how small mammal biomass density was calculated can be found in appendix S3 of electronic supplementary material. Small mammal biomass densities in kg ha⁻¹ for the six different habitat types are: mesic grasslands 5.49, xeric grasslands 3.33, sagebrush 1.30, burned sagebrush 1.76, forest 1.02 and burned forest 1.01. Black contour lines show topographic relief in metres.