Twenty years of Road Ecology: a Topical Collection looking forward for new perspectives

Roadkill in a Mediterranean island: Evaluating ten-years of official records

Roadkill is a global issue contributing to biodiversity decline which is increasingly recognized by scientists and decision-makers. In Cyprus, a biodiversity hotspot with one of the highest road densities in Europe, the impact of roads on wildlife has been largely overlooked due to the absence of life-threatening collisions. We analysed data from a 10-year roadkill dataset (2013-2022) collected systematically by the Department of Public Works across 27 main roads, primarily aimed at driver safety. Due to the absence of spatial attributes for roadkill locations, the dataset was analysed to identify taxonomic, seasonal, and temporal roadkill trends in Cyprus for the first time. A total of 1,985 roadkill incidents were recorded, involving seven wildlife taxa: foxes (44%), birds (26%), hedgehogs (11.5%), snakes (7%), hares, rats, and lizards. Most roadkill occurred in the Nicosia district (65%). Statistical analyses using chi-square tests with post-hoc Bonferroni corrections revealed strong associations between road types and taxa. Fox and bird roadkill incidents were most common on highways, while hedgehogs and snakes were frequent on secondary interurban or rural roads. Roads near protected areas exhibited higher roadkill frequencies than highways. A positive relationship between traffic volume and roadkill risk was evident, with higher traffic roads posing greater risks. Seasonal patterns showed increased roadkill during spring and summer, peaking in June. This synthesis provides crucial insights into roadkill patterns, offering guidance for conservation and mitigation actions. However, the current monitoring system, focused on driver safety, is inadequate for comprehensive roadkill reporting. Key limitations, such as the absence of spatial data and weaknesses in the protocol, have been identified, with recommendations for improvement proposed to enhance future monitoring efforts.

Descriptions of new species and new records of water bugs (Hemiptera: Heteroptera: Gerromorpha & Nepomorpha) from southeastern Brazil

Although most of the diversity of true bugs (Hemiptera: Heteroptera) is terrestrial, over 550 species of water bugs (Heteroptera: Gerromorpha, Leptopodomorpha & Nepomorpha) have been recorded from Brazil alone. Southeastern Brazil, composed of the states of Esprito Santo, Minas Gerais, Rio de Janeiro and So Paulo, is the best studied region of the country, but there are still knowledge gaps in the area. Here, two new species are described from Esprito Santo: Hydrometra ruschii Cordeiro, Rodrigues & Moreira, sp. nov. and H. tuberculata Cordeiro, Rodrigues & Moreira, sp. nov. (Gerromorpha: Hydrometridae). Furthermore, new records from southeastern Brazil are provided for 78 species of water bugs, of which 19 are firstly recorded from Esprito Santo, four from Minas Gerais, eight from Rio de Janeiro, and seven from So Paulo.

Aliens on the Road: Surveying Wildlife Roadkill to Assess the Risk of Biological Invasion

Monitoring the presence and distribution of alien species is pivotal to assessing the risk of biological invasion. In our study, we carried out a worldwide review of roadkill data to investigate geographical patterns of biological invasions. We hypothesise that roadkill data from published literature can turn out to be a valuable resource for researchers and wildlife managers, especially when more focused surveys cannot be performed. We retrieved a total of 2314 works published until January 2022. Among those, only 41 (including our original data) fitted our requirements (i.e., including a total list of roadkilled terrestrial vertebrates, with a number of affected individuals for each species) and were included in our analysis. All roadkilled species from retrieved studies were classified as native or introduced (domestic, paleo-introduced, or recently released). We found that a higher number of introduced species would be recorded among roadkill in Mediterranean and Temperate areas with respect to Tropical and Desert biomes. This is definitely in line with the current knowledge on alien species distribution at the global scale, thus confirming that roadkill datasets can be used beyond the study of road impacts, such as for an assessment of different levels of biological invasions among different countries.

Genetic footprints of a rapid and large-scale range expansion: the case of cyclic common vole in Spain

In the Anthropocene, many species are rapidly shifting their ranges in response to human-driven habitat modifications. Studying patterns and genetic signatures of range shifts helps to understand how species cope with environmental disturbances and predict future shifts in the face of global environmental change. We investigated the genetic signature of a contemporary wide-range expansion observed in the Iberian common vole Microtus arvalis asturianus shortly after a colonization event. We used mtDNA and microsatellite data to investigate patterns of genetic diversity, structure, demography, and gene flow across 57 localities covering the historical range of the species and the newly colonized area. The results showed a genetic footprint more compatible with a true range expansion (i.e. the colonization of previously unoccupied areas), than with a model of "colonization from within" (i.e. local expansions from small, unnoticed populations). Genetic diversity measures indicated that the source population was likely located at the NE of the historical range, with a declining gradient of genetic diversity towards the more recently invaded areas. At the expansion front, we observed the greatest gene flow and smallest pairwise differences between nearby localities. Both natural landscape features (rivers) and recent anthropogenic barriers (roads, railways) explained a large proportion of genetic variance among populations and had a significant impact on the colonization pathways used by voles.

Habitat Suitability Based Models for Ungulate Roadkill Prognosis

Simple Summary

Red deer, roe deer and wild boar movements and crossings of the two highways in Lithuania were modeled. Validity of obtained models was tested by comparing the pathway predictions to the real roadkill and roadkill cluster locations in 2002–2009 (at the time the models were created) and in 2010–2017 (testing the prognostic value of these models). Across both periods and on both highways, the roe deer roadkill locations were significantly closer to the model-predicted pathways than to randomly selected points. The prediction of roadkill locations was also good for wild boar. The roe deer roadkill clusters and multi-species clusters were significantly better represented by the model than by random distribution. Thus, habitat suitability-based models of ungulate movement are recommended as an additional tool for planning wildlife-vehicle collision mitigation measures.

Abstract

Roads do not only have a detrimental effect on nature (fragmenting habitats, isolating populations and threatening biodiversity), but the increasing numbers of wildlife-vehicle collisions are also a direct threat to humans and property. Therefore, mitigation measures should be placed with respect to animal distribution and movements across the roads. We simulated red deer, roe deer and wild boar movements in Lithuania, focusing on the two main highways A1 and A2. Using regional habitat suitability and linkage models, we calculated movement pathways and the most probable crossing zones in 2009. The prognostic value of these models was tested by comparing the pathway predictions to the real roadkill and roadkill cluster locations in 2002–2009 and 2010–2017. Across both periods and on both highways, the roe deer roadkill locations were significantly closer to the model-predicted pathways than to randomly selected points. The prediction of roadkill locations was also good for wild boar. The roe deer roadkill clusters and multi-species clusters were significantly better represented by the model than by random distribution. On both highways, the biggest differences in distance from the predicted locations were near big cities. We recommended wildlife movement models as an additional tool for planning wildlife-vehicle collision mitigation measures and we advise measures for increasing their predicting power.