Geography of roadkills within the Tropical Andes Biodiversity Hotspot: Poorly known vertebrates are part of the toll

Pablo Medrano‐Vizcaíno,Santiago Espinosa

doi:10.1111/btp.12938

Abstract

AbstractWe explore the effect of roads in animal mortality within the Biodiversity Hotspot with the highest number of endemic species of vertebrates on Earth, the Tropical Andes. Our objectives were to know which species are killed on roads in this particularly biodiversity‐rich area and how landscape composition and configuration influences roadkills. We systematically looked for roadkills along roads that border three protected areas in the Ecuadorian Andes. To evaluate our hypotheses, we used correlation, logistic regression, and GIS analyses. We surveyed a total of 7128 km and observed a roadkill rate of 6.24 (95% CI = 5.35–7.14) individuals per 100 km/day. Roadkills included poorly known endemic and endangered vertebrates; among them, one undescribed snake species of the genus Atractus. Most roadkills were by pastures, the dominant vegetation by roads in our study area. Roadkills were more likely to occur near bridges and were more frequent at greater distances from natural vegetation, towns, and rivers. We conclude that pastures and bridges may be functioning as ecological traps for small and poorly known vertebrates. Mitigation measures could include increasing road permeability to wildlife by constructing culverts in critical points where mortality is high, and the adaptation of areas beneath bridges for them to function effectively as wildlife underpasses. These measures should be complemented with fences to exclude vertebrates from roads in areas near wildlife passages and along pastures. We encourage the development of similar studies in biodiversity‐rich areas to inform mitigation measures that can be adapted to local conditions.Abstract in Spanish is available with online material.

Highlights

There are over 40,000,000 km of paved roadway lanes in the world (Dulac, 2013)
We explore the effect of roads in animal mortality within the Biodiversity Hotspot with the highest number of endemic species of vertebrates on Earth, the Tropical Andes
We systematically looked for roadkills along roads that border three protected areas in the Ecuadorian Andes

Summary

| INTRODUCTION

There are over 40,000,000 km of paved roadway lanes in the world (Dulac, 2013). Many of those roads dissect natural habitats where they cause multiple and detrimental ecological effects. It is suspected that collisions with vehicles could have negative consequences in the genetic diversity of wildlife populations in natural areas dissected by roads (Jackson & Fahrig, 2011) This can be a important threat for endangered species with small populations numbers; for example, between 2015 and 2016, 79 percent of the mortality of the Florida panther (Felis concolor coryi) was caused by vehicle collisions (FWC, 2016). In Goiás-Brazil, mammals represent 74.21 percent of roadkilled wildlife (Silveira-M iranda et al 2017); in Costa Rica, amphibians accounted for 93.5 percent of roadkill events (Arévalo et al 2017); and in Tanzania, birds accounted for 50 percent of roadkilled animals (Kioko et al 2015) This variation likely responds to intrinsic differences in animal communities, landscape composition and configuration, and road characteristics (Ciocheti et al 2017; Clevenger et al 2003; Medinas et al 2013), which will be unique for each study site. The specific objectives of our research were as follows: (1) to determine the frequency and species composition of wildlife roadkills; (2) to explore how different landscape attributes are related to roadkills; and (3) to evaluate the relationship of vehicular traffic with roadkills

| METHODS

| RESULTS

Findings

| DISCUSSION