SEASONAL CHANGES IN THE MULE DEER (Odocoileus hemionus Crooki) DIET IN CHIHUAHUAN DESERT SHRUB

Abstract

The Chihuahuan Desert presents specific constrains for mule deer (Odocoileus hemionus) populations; given that mule deer are large herbivores, both forage quality and quantity play an important role in the species survival in the desert. The aim of the present study was to evaluate habitat condition of an area where mule deer inhabit. This zone, located in a region of the Chihuahuan Desert exhibits different types of dominant vegetation (medium scrubland and grassland). Vegetation percent cover, diet composition and forage nutritional value, with crude protein content (CP), were evaluated for different vegetation types in three annual seasons: moderate-dry, moderate-humid and cold-dry, during 2012 and 2013. We classified forages into three categories: trees-shrubs, grasses-herbs, and succulents. The results show diet composition changes during annual seasons, with succulents as well as tree-shrubs as the principal components. Treesshrubs exhibited in average a higher CP percentage (13.6%), for the moderate-humid season. The medium scrubland area exhibited higher density on trees and shrubs; in addition, this area presents higher hills and deeper slopes, making it a region with high aptitude for mule deer sustainment within the Chihuahuan Desert.