Densidade populacional de raposa-do-campo Lycalopex vetulus (Carnivora, Canidae) em áreas de pastagem e campo sujo, Campinápolis, Mato Grosso, Brasil

Abstract

In face of the growing disturbance of the Cerrado biome, due to the expansion of the agricultural borders of Central Brazil, it becomes important to evaluate the adaptation capacity of animal species to the anthropized environment. Thus, this work was developed aiming to estimate and compare the population density of hoary fox Lycalopex vetulus (Lund, 1842) in two areas of Central Brazil with distinct disturbance degrees, pasture and campo sujo, a vegetation type of Cerrado. For this, during the period of August to November 2005, nocturnal sampling were done along linear transects, totaling 129.8 km in the campo sujo and 62.08 km in the pasture. A total of 23 sightings of hoary fox was obtained in campo sujo and 52 in the pasture. Estimations of population density were made using the Distance 5.0 software, which chose the half normal + hermite adjust as the model with best fit. Population density was higher in the pasture (D=4.28 individuals/km2; IC=2.69 - 6.82) than in the campo sujo (D=1.21 individuals/km2; IC=0.73 - 2.01), what is likely related, mainly, to higher availability of food and reduction of potential predators. As its diet is composed basically of termites, especially from the genera Syntermes and Cornitermes, the hoary fox find in the pasturage area an alimentary base abundant and stable. Moreover, the environmental simplification, due to the pasture implantation, end up reducing or to local extinction potential predators of the hoary fox, such as Chrysocyon brachyurus (Illiger, 1815), supporting the increase of population density of this specie in this kind of environment. Results indicate that the Cerrado endemic hoary fox is able to survive, and even proliferate, in highly modified areas of the Cerrado.