Perda da fauna de mamíferos silvestres por atropelamento no bioma pampa

Abstract

Highways are among the environmental changes that caused more intense impacts in natural landscapes in the XXth century. The result is a decrease in three levels of diversity – whitin a single specie; above species level; and the overall biodiversity. Mammals head the list of dead-on-road registers. This study aims to estimate the loss of the dead on road indigenous mammalian fauna in a highway of the Brazilian Pampa. The mammalian species dead-on-road between km 424 and 428 of the BR-290 highway, around five kilometers from the urban downtown of the São Gabriel municipality, Rio Grande do Sul State, were conducted between June, 2009 and February, 2010. The route was covered by bicycle, at a velocity of around 10 km/h, allowing a better visualization of small animals in the road and sideways. Overall, 120 dead-on-road animals were registered, belonging to 10 families and 12 genera. The most commonly dead-on-road species found were Cavia aperea, Conepatus chinga, Akodon sp., Eptesicus sp,. and Cerdocyon thous. The number of dead-on-road mammals can be considered high in comparison to other studies performed in Brazil. According to these data, two hypotheses can be pointed: that the observed species have enough ecological plasticity to live in altered ecosystems areas or that the changes in the vegetation were so fast that the populations did not yet reflect the alterations introduced by the agricultural monocultures in the region. Further studies about the populations living nearby the highway are needed, in order to estimate risks of local extinction and to deliberate mitigating actions.