Use of a Crested Wheatgrass Seeding by Black-tailed Jackrabbits

Abstract

Black-tailed jackrabbit grazing pressure on a seeding of crested wheatgrass surrounded by native shrub vegetation has been estimated by the use of pellet counts. Grazing pressure falls off rapidly away from the edge of the field, 70% of the total being concentrated in a 300-m band around the edge of the field. By calibrating the pellet counts against others taken in an area of known jackrabbit density, and by using values available in the literature for forage consumption of jackrabbits, an estimate has been made of the absolute grazing pressure on the field in the 300-m band which is predominantly used. The forage removed by jackrabbits in this zone is estimated to be in the order of 60 kg/ha/yr. This is less than 10% of nearly all the yield values found, including those in poor years, in comparable seedings in this area. Apparently jackrabbits do not cause serious damage to established seedings of wheatgrass even when jackrabbit densities are high, as they were at the time of this study.