SHORT AND NARROW ROADS CAUSE SUBSTANTIAL IMPACTS ON WILDLIFE

Marcelo Magioli,Adriana Marques Nascimento,Victor Hugo Vasconcellos Prado Andrade,Katia Maria Paschoaletto Micchi De Barros Ferraz Ferraz,Renata Alonso Miotto,Fernanda Delborgo Abra,Marcel Pieter Huijser,Maísa Ziviani Alves Martins,Alex Augusto Abreu Bovo

doi:10.4257/oeco.2019.2301.09

Abstract

Short and narrow roads are generally overlooked when assessing road impacts on biodiversity. However, these roads bisect natural environments and may cause significant impacts on wildlife in local scale. Thus, we monitored roadkills along a short two-lane road (CPM road) in Southeastern Brazil and propose mitigation strategies to reduce wildlife mortality. We monitored roadkilled vertebrates along 5 km of CPM road from 2010 to 2016 and we also compiled data from previous studies along the same road. We conducted a hotspot analysis to identify CPM road areas with significant roadkill aggregation. We recorded 77 roadkilled vertebrates from 14 taxonomic groups along the CPM road. Mammals were the most frequently recorded group (91% of roadkills), which represented 56% of all medium- and large-sized mammal species known to occur in the study area. We identified three roadkill hotspots along the CPM road. Two of them were located at two stream crossings, where the road cut across the associated riparian forests, and the other was at a road section with water drainage from a pond, also connected to a riparian forest. These riparian forests are part of the remaining natural habitat that provides connectivity between the forest remnants in the landscape, and therefore, for wildlife. Our results showed that even short and narrow roads can have considerable roadkill, which may have severe effects for wildlife on a local scale. The results stress the need to carefully look at these types of roads and propose measures to reduce impacts. We propose the creation of safe crossing opportunities in the hotspot zones combined with wildlife fencing to keep the animals off the road and guide them towards the safe crossing opportunities.

Highlights

The construction of roads and other linear infrastructure have modified the landscape to the point where it is uncommon to find areas distant from roads and areas that remain unaffected by them (Forman & Alexander 1998, Coffin 2007)
CPM road runs from the northeastern edge of the urban area of Piracicaba, bisects the Escola Superior de Agricultura “Luiz de Queiroz” (ESALQ), a campus of the University of São Paulo, and borders the Instituto de Pesquisas e Estudos Florestais (IPEF)
Because of the linear nature of roads, they bisect a wide variety of environments, especially in human-modified landscapes (HMLs)

Summary

Introduction

The construction of roads and other linear infrastructure have modified the landscape to the point where it is uncommon to find areas distant from roads and areas that remain unaffected by them (Forman & Alexander 1998, Coffin 2007). Species that are both common and large are a particular concern for human safety (CDC 2004, Langley et al 2006), while those that are rare or threatened, are primarily a biological conservation priority, though there are some exceptions (e.g., Medici et al 2016). For the latter, the loss of only a few individuals can already result in a local population decline, or even local or regional extirpation (Coffin 2007)

Methods

Results

Conclusion