Wildlife roadkill mortality in the Upper Paraná Atlantic forest, Argentina

Abstract

The expansion of transport networks is one of the greatest threats to biodiversity, leading, among other things, to increasing risk of wildlife mortality from accidents. The objective of the present study is to evaluate the roadkills that occurred between 2012 and 2016 in a 34 km segment along the National Route No. 12 in the Upper Paraná Atlantic forest (Argentina). This segment crosses several natural reserves and supports massive touristic flow. The number of road accidents was compared between seasons of the year, type of vegetation and presence of protected areas, using mixed generalized linear models. We mapped the distribution of accidents to identify critical sites. During the 47 months surveyed, we observed 1784 roadkills: 67.5% mammals, 25.2% birds and 7.3% reptiles. The species with the greatest number of recorded accidents was the white-eared opossum (Didelphis albiventris), followed by the black-and-white tegu (Tupinambis merianae) and the tropical screech owl (Megascops choliba). Only the reptiles showed significant differences in roadkills between seasons. 72.6% of the accidents occurred in areas with presence of native forest. 70.7% of accidents occurred within protected areas. We identified 13 critical kilometers where the application of measures such as the placement of speed reducers and the adequacy of drainage structures of streams as underpasses are proposed. Once the proposed measures have been implemented, their long-term effectiveness should be evaluated.