Habitat and Dietary Relationships of the Pygmy Rabbit

Abstract

Vegetal habitat characteristics and annual dietary selection were examined for the pygmy rabbit in southeastern Idaho. Areas selected for habitation by pygmy rabbits had a significantly greater woody cover and height than other areas. Total grass-forb biomass was similar in rabbit and nonrabbit sites. Grass biomass was least and forb biomass greatest where pygmy rabbits were most abundant. Sagebrush was eaten throughout the year, although in lesser amounts in summer (51%) than in winter (99%0). Grasses and forbs were eaten through the summer (39 and 10%, respectively) and decreased in the diet through fall to winter. Sagebrush is critical to the pygmy rabbit for both food and cover, although in this study, cover and height of woody vegetation appeared to be the critical features of the habitat selected for. This fact should be considered before brush removal treatments are applied within pygmy rabbit range. Wildlife habitat research has been termed the cornerstone in management (Reynolds 1974) but is often poorly accomplished or entirely neglected. Manipulation of habitat is common, but should be undertaken with an understanding of resident wildlife species' requirements for food and space. Throughout the western United States, there is an historical and present day practice of removing sagebrush (Artemisia spp.) by spraying, mechanical treatment, and burning to increase forage production. Only Green was at the time of the study, research associate, Botany and Range Science Department, Brigham Young University, Provo, Utah 84602. Current address is: U.S. Sheep Experiment Station, Dubois, Idaho 83423. Flinders is associate professor, director Wildlife and Range Resources Graduate Program, 407 WIDB, Brigham Young University, Provo, Utah 84602. The efforts of Jeff Johansen and Forrest Luke, Laboratory Assistants, Brigham Young University, for reading and preparing dietary slides is appreciated. The work was supported by USDA Western Kegion Federal Cooperative Agreement No. 12-14-5001-264. Manuscript received December 22, 1978. recently has the impact of this activity on wildlife been considered and then only for a few species (Powell 1969; Braun et al. 1977; Renwald 1977). Additional information is required before habitat can be altered for range improvement with a knowledge of possible impacts on wildlife populations.