DIET, POPULATION AND CARRYING CAPACITY OF THE WHITE TAILED DEER (Odocoielus virginianus) UNDER TWO HABITAT CONDITIONS IN TLACHICHILA, ZACATECAS, MÉXICO

Abstract

With the objective of evaluating the carrying capacity for the white tailed deer (Odocoileus virginianus) under two habitat conditions, and of understanding the current situation of the deer population, a study was developed inside a conserved area and another disturbed by agriculture in the Sombreretillo UMA, in Sierra de El Laurel, Tlachihila, Zacatecas, México. The floristic inventory of the study area was determined, as well as the availability of dry matter (DM), species of trees, shrubs, herbs and grasses, and maize (Zea mays L.) and oats (Avena sativa L.) crops. The botanical composition of the diet (BCD) of the deer, the carrying load in both habitats, and the population density of the deer were determined. A higher availability of DM was found (p=0.0075) in the rainy season (1213.2 Kg ha^-1), and in the fragmented and conserved area it was similar (p>0.05). The grasses presented higher (p=0.0075) amount of biomass available than the trees, shrubs and herbs. The BCD of the deer consisted of 25 species from 17 families. Those most frequent in the diet were Asteraceae (7) and Fabaceae (3). The carrying capacity in the conserved area during the dry season was 34.67 ha v^-1 and it was 38.40 ha v^-1 for the fragmented area. For the case of the rainy season in the conserved area, the carrying capacity was 9.50 ha v^-1 and in the fragmented area 7.47 ha v^-1. The population densities were similar (p>0.05) in the conserved area (0.0423 v ha^-1) and in the fragmented area (0.0392 v ha^-1), which gave a population estimation of 22 deer in the conserved area, and 14 in the fragmented area. The deer density was not affected by habitat fragmentation since the carrying capacity of the habitat, both conserved and fragmented, during the rainy season was higher than the population estimated