Influence of Landscape Factors on Amphibian Roadkills at the National Level

Abstract

Roads exert multiple effects on wildlife, from animal mortality, habitat and population fragmentation, to modification of animal reproductive behaviour. Amphibians are the most frequently road-killed animal group. Many studies have attempted to analyse the factors driving amphibian casualties on roads, but these factors are limited to the roads themselves (e.g., traffic, type of roads, roads crossing water bodies) or to structures along them (e.g., ditches, walls). Sometimes, roadkills are related to land use along the roads. We analysed the influence of landscape factors on roadkill hotspots at the national level (Slovenia). Specifically, we aimed at: (1) identifying hotspots of roadkills, (2) analysing whether records of amphibian presence on roads are related to the distribution of water bodies and (3) analysing which factors (proximity to water bodies or human factors) explain the distribution of hotspots. Hotspots were identified by Malo’s method. Roadkills were modelled with Maxent for the first time in Slovenia. The relationships between amphibian presence and hotspots with factors were analysed with GLM. A total of 237 road sections were identified as hotspots, corresponding to 8% of road sections and containing 90% of road-killed individuals. Proximity to forests, meadows and agricultural land were the most important variables in Maxent models. The number of roadkills depended on the proximity to agricultural land, forests, water bodies and wetland areas, while the number of hotspots additionally depended on the proximity to urban settlements.

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

“…(4) Distance to nearest town should be associated with traffic, with a higher vehicle frequency near towns; we could expect to find that wildlife is at higher risk of being roadkilled in areas where vehicle frequency is higher (Lodé, 2000;Orlowski & Nowak, 2006). (5) We expected roadkills to be more frequent along road sections that cross forest cover, which has been observed in previous studies (e.gMalo et al 2004;Sillero et al 2019). Before model implementation, we evaluated multicollinearity between our covariates with the variance inflation factor (VIF), which was estimated with the function vif in R package car (Fox & Weisberg, 2019).…”

Spatio-Temporal Patterns and Consequences of Road Kills: A Review

“…Numerous other studies have followed suit [ 12 , 22 , 45 , 58 ], using their own classification systems. Regardless of how the road mortality factors are grouped, typically, no single influence operates in isolation.…”

“…For instance, Kazemi et al [2] identified four main elements of road kills; that is, the major groups of factors for road mortalities. These are: Numerous other studies have followed suit [12,22,45,58], using their own classification systems. Regardless of how the road mortality factors are grouped, typically, no single influence operates in isolation.…”

“…Relevant authorities in road management and safety will usually address AVCs regarding how they affect the people involved. Conservationists and ecologists, however, have focused a significant amount of research on these types of accidents, in terms of road kills [ 1 , 19 , 20 , 21 , 22 , 23 ]. Gaps in the literature on AVCs have reflected an inconsistent approach by both relevant authorities and specialists addressing the subject matter.…”

An Improved Mobile Mapping System to Detect Road-Killed Amphibians and Small Birds

“…Monitoring wildlife-vehicle collisions (WVCs) is essential to establish correct mitigation measures. Many countries have national monitoring systems for identifying species' mortality hotspots [8,9]. These surveys are performed by car at low speed (20-30 km/h) and are therefore expensive and time-consuming.…”