DENSITY AND HABITAT USE BY MULE DEER (Odocoileus hemionus eremicus RAFINESQUE) IN COAHUILA, MÉXICO

Abstract

Mule deer (Odocoileus hemionus eremicus RAFINESQUE) has decreased its population in Coahuila, México, during the second half of the 20th Century due to anthropogenic factors and drought. The factors that affect the habitat use of the mule deer during dry and rainy seasons were evaluated, and the relative density was determined in three plant associations: 1) izotal (Yucca carnerosana), 2) lomerío-lechuguilla (Agave lechuguilla)-sotol (Dasylirion leiophyllum), and 3) open grassland (Bouteloua curtipendula, Aristida divaricata, and Hilaria mutica) in an area of Coahuila, México. The deer density was estimated through group counting of scat in parcels throughout transects with systematic-stratified sampling; and variables from the habitat were used to evaluate and identify their use by the deer through principal component analysis, as well as techniques for availability and habitat use. The deer preferred hills dominated by sotol regardless of the season, and the greatest density was found during the dry season with 11 deer km^2-1, 4.7 deer km^2-1 for the early-rainy season, and 1.8 deer km^2-1 in the late-rainy. The relevant variables for habitat use in the dry season were slope of the terrain, density of succulent plants, key plants and thermal cover; and during the rainy season, slope of the terrain, density of succulent plants, key plants, thermal cover and species wealth. The lomeríolechuguilla- sotol plant association represented an important component for mule deer.