Southwest Deserts Ecoregion

Abstract

This chapter describes the Southwest Deserts Ecoregion where rainfall is low, averaging from <4–20 inches (<10–51 cm), and highly variable; productivity of mule deer habitat is dependent on sporadic rainfall events. Mule deer populations in the Southwest Deserts Ecoregion may suffer high summer fawn mortality during periods of drought. Breeding season and fawning periods are later in the year and more extended than for mule deer populations in more northern areas, which is an adaptation to the later phenology of plant growth. In many areas of the Southwest Deserts mule deer occupy the lower elevation shrublands and grasslands. Mule deer may make long-distance seasonal movements to temporarily take advantage of precipitation. Habitat productivity and the resulting mule deer abundance in the Southwest Deserts is reliant on precipitation, and managers focus on retaining and improving the amount and quality of nutrition available on the landscape. Once habitat in the Southwest Deserts is disturbed, it may take several decades of active management to recover in this arid ecoregion. Close attention must be paid to appropriate grazing levels, adequate water distribution, managing prevalence of invasive plant species, and promoting forb and shrub production.