Atropelamentos de fauna em uma rodovia do Pampa brasileiro

Abstract

Brazil is one of the countries with highest biological diversity index of the world. However, this diversity gives, many times, an idea of abundance in number of species and in number of individuals, fact that may not correspond to the reality for many species. With main distribution in southern Brazil and parts of Uruguay and Argentina, the Pampa biome presents regions not well known in relation to the ecology of highways. One of the man-made actions that has gained special focus by researchers is the build and use of highways, which cause ecological disequilibrium, promoting loss of environmental quality. In the last decades many studies have shown different impacts of highways in the vertebrate communities, such as habitat fragmentation and death by running over. This study aimed to estimate the loss of terrestrial invertebrates by running over and relate the results to their ecology species. Sampling. The study was performed from June 2009 to Mars 2010 and consisted in travelling by car through a patch of 12 km of the highway BR-290, with a velocity of around 50 km/h. A total of 74 travels were performed, twice a week. In these travels, 438 dead-on-road animals were observed, covering all vertebrate taxa. Among these animals, 26 were amphibians (four species), 119 were reptiles (13 species), 123 were mammals (16 species) and 170 were birds (23 species). The fact that birds are the most affected group is interesting, since many studies in the same area present mammals as the more affected group. The mortality by running over is the most visible aspect of the deleterious effects of highways and can, in some species, cause accentuated demographic decrease. In addition, the behaviour of the communities are changed. For many animals, highways mean an easier source of feed, because there are no large supply of items such as carcasses and grains. The exploitation of food availability was the major factor responsible for the high rate of pedestrian accidents observed in the present. However, the trampling of animals with large areas of life seem more connected simply to the displacement of individuals.