Roadkill and influence of landscape in wild mammals of survival of medium and large

Abstract

Roadkill of wild vertebrates are among the greatest negative impacts from linear ventures, being a direct cause of biodiversity decline and environmental quality. In addition to wildlife-related accidents, highways play an important role in environmental degradation, as they favor human exploration in previously remote areas. The environmental impacts of the projects installed in the vicinity of the roads, operate in a synergistic and cumulative manner on the environment, contributing to the high mortality rates of wildlife through road accidents. Fauna passages are among the most efficient mitigation measures for the prevention of road accidents. The present study had as objective to analyze road-kills of the medium and large mammals on the highway BR-497, between the municipalities of Uberlândia and Prata, MG, and to characterize the landscape uses of the linear enterprise by means of images, indicating measures that help In the reduction of mortality of wildlife individuals by trampling. The data of the run-offs were collected monthly from July 2015 to July 2016. There were 49 individuals distributed in 16 species, including three species under threat of extinction, the maned wolf (Chrysocyon brachyurus), anteater (Myrmecophaga tridactyla) and field fox (Lycalopex vetulus). The hotspots analyzed evidenced three nuclei with a higher incidence of accidents, which means that it is necessary to implement mitigation measures with the capacity to minimize the observed mortality, suggesting in this case the installation of structures that act as fauna overpass. The landscape analysis was carried out by means of remote sensing with satellite image (LANDSAT 8), supervised classification of land use and occupation by means of the Maximum Likelihood algorithm, which resulted in a percentage of anthropic use of approximately 80,00%. The analysis of the percentages of native vegetation was made through the construction of vegetation masks and buffers away from the central axis of the highway (1, 9 and 18 km), evidencing that the totals of natural remnants tend to reduce as the approach of the highways . In relation to trampling involving endangered fauna, considering the limits of their living areas, the results show that individuals suffer from strong environmental pressures, since a large part of the area necessary to establish their biological and ecological functions is under Anthropic use. In addition, the analysis for the remnants present in the study area, showed that the fragments classified as large (<4 km²) are scarce and are strongly influenced by environmental disturbances. Thus, in the current scenario, the conservation of species, mainly of medium and large mammals, that generally require large areas for the maintenance of their activities, depends directly on the establishment of goals that promote the connectivity and quality of habitats and of measures that minimize roadkill of wild life mortality on the BR-497 highway. In this sense, the present study may serve as a data base assisting in the conservation strategy for wild mammals of medium and large size present in the study region.