Number Of Roadkills Research Articles

Importance of professional roadkill data in assessing diversity of mammal roadkills

With considerable under-reporting of roadkills, the impact of transport on biodiversity is mostly underestimated. The main goal of this study was to compare official roadkill records with data collected by professional biologists. On roads with different traffic intensities, we compared species richness, diversity indices and species composition with regard to the data sources and performed roadkill hotspot analysis. Biologists recorded more mammal species killed, a higher diversity index and a different composition of dominants in the roadkills, as well as different numbers and locations of hotspots. Traffic intensity and population size explained 63–93% of the variation in roadkill numbers in ungulates. Professional monitoring effort and traffic intensity explained nearly 90% of variation in roadkill numbers, 70% of variation in recorded species and 40% of diversity variation. With greater accuracy than available official data, professional roadkill diversity data should be used in wildlife-vehicle accident analysis and in planning road safety infrastructure.

The Australian Roadkill Reporting Project-Applying Integrated Professional Research and Citizen Science to Monitor and Mitigate Roadkill in Australia.

Simple SummaryAustralia has no database of national roadkill. The current research project fills that knowledge gap by developing a roadkill reporting application that enables professional and citizen scientists to record photographs of roadkill with location, time and date. This embodies the concept of ‘One Welfare’ as it affects humans, animals and the environment. Uploaded to a website, these data can identify roadkill hotspots, tabulate species of animals killed and potentially be used for ecological studies of roadkill numbers, species distribution, population trends, animal behaviour and disease. Initial results indicate that mammal roadkill mostly occurs at night and that of birds and reptiles during daytime. Mammals make up three-quarters of the roadkill recorded and this includes endangered species. Two examples of roadkill hotspots are shown in Queensland and Tasmania. These will enable further research to suggest how roadkill mitigation measures may be optimally employed.Australia has no national roadkill monitoring scheme. To address this gap in knowledge, a roadkill reporting application (app) was developed to allow members of the public to join professional researchers in gathering Australian data. The app is used to photograph roadkill and simultaneously records the GPS location, time and date. These data are uploaded immediately to a website for data management. To illustrate the capacity to facilitate cost-effective mitigation measures the article focuses on two roadkill hotspots—in Queensland and Tasmania. In total, 1609 reports were gathered in the first three months of the project. They include data on mammals (n = 1203, 75%), birds (n = 125, 7.8%), reptiles (n = 79, 4.9%), amphibians (n = 4, 0.025%), unidentified (n = 189, 11.8%) and unserviceable ones (n = 9). A significant finding is variance in the distribution of mammals and birds at different times of day. These findings reflect diurnal variation in the activity levels of different species and underline the need for data on a targeted species to be collected at appropriate times of day. By continuing to facilitate roadkill monitoring, it is anticipated that the data generated by the app will directly increase knowledge of roadkill numbers and hotspots. Indirectly, it will provide value-added information on animal behaviour, disease and population dynamics as well as for species distribution mapping.

Effectiveness of small road tunnels and fences in reducing amphibian roadkill and barrier effects at retrofitted roads in Sweden.

Schemes to reduce road impacts on amphibians have been implemented for decades in Europe, yet, several aspects on the effectiveness of such schemes remain poorly understood. Particularly in northern Europe, including Sweden, there is a lack of available information on road mitigation for amphibians, which is hampering implementation progress and cost-effectiveness analyses of mitigation options. Here, we present data derived from systematic counts of amphibians during spring migration at three previous hot-spots for amphibian roadkill in Sweden, where amphibian tunnels with guiding fences have been installed. We used the data in combination with a risk model to estimate the number of roadkills and successful crossings before vs. after mitigation and mitigated vs. adjacent non-mitigated road sections. In mitigated road sections, the estimated number of amphibians killed or at risk of being killed by car traffic decreased by 85–100% and the estimated number successfully crossing the road increased by 25–340%. Data, however, suggested fence-end effects that may moderate the reduction in roadkill. We discuss possible explanations for the observed differences between sites and construction types, and implications for amphibian conservation. We show how effectiveness estimates can be used for prioritizing amphibian passages along the existing road network. Finally, we emphasize the importance of careful monitoring of amphibian roadkill and successful crossings before and after amphibian passages are constructed.

Bad moon rising? The influence of the lunar cycle on amphibian roadkills

Annually, roads, and their associated users, are responsible for millions of roadkills worldwide. Mortality affects multiple taxonomic groups, but amphibians are particularly vulnerable, due to their size and underreporting. In fact, very high mortality frequencies can occur, mostly during short periods of time, when individuals migrate to and from reproduction areas (e.g., ponds). In this study, we assess the influence of the lunar cycle on amphibian roadkills, while accounting for weather conditions. As expected, the main environmental effects explaining roadkill numbers were weather related, with increases in minimum air temperature, average relative air humidity, and cumulative rainfall during the previous 24 h having a positive effect on roadkill numbers for all studied species. However, the lunar cycle also affected roadkills for two of the studied species. Darker nights had higher numbers of roadkills of Pleurodeles waltl, while moonlit nights had higher numbers of Salamandra salamandra. As such, these moon effects are species specific. Animals that are more active in moonlight may be at an advantage if their visual acuity is better than that of their predators. We hypothesize that differences between species in the response to moonlight may be due to differences perceived in predation risk. This information should be considered when designing mitigation measures. Volunteer actions, for instance, can be planned and coordinated keeping in mind the most appropriate weather conditions for the general amphibian community and specific phases of the lunar cycle for particular species.

Roadkill of animals on the road passing from Kalaburagi to Chincholi, Karnataka, India

The road passing from Kalaburagi to Chincholi in Karnataka, India, is around 70km and is a state highway having different types of moderately thick vegetation on either side. The animals utilizing this vegetation face huge threats from vehicular traffic, as was observed in recent years. Although this road does not have heavy traffic, there are significant numbers of roadkills. This study was conducted from February 2015 to January 2016. During the one-year period of the study, the mean frequency of heavy vehicles was 154 per day. Among the 283 roadkills recorded, 52 individuals belonged to the class Amphibia, constituting 18.37% of the total roadkills; no amphibian was killed in the summer season whereas 35 and 17 individuals were killed in the rainy season and in the winter season, respectively. Fifty-two individuals belonged to the class Reptilia, constituting 18.37% of the total roadkills; on an average, 10±5.8 individuals were killed in the summer season, 2.5±0.71 in the rainy season, and 3.5±2.12 in the winter season. Sixty-one individuals belonged to the class Aves, constituting 21.55% of the total roadkills; on an average, 5.71±3.03 individuals were killed in the summer season, 2.66±2.08 in the rainy season, and 4.33±3.51 in the winter season. One-hundred-and-eighteen individuals belonged to the class Mammalia, which was the most affected among the roadkills, constituting 41.69% of the total roadkills; on an average, 5.33±5.08 individuals were killed in the summer season, 5±3.9 in the rainy season, and 4.6±2.7 in the winter season. Under the IUCN Red List category, the majority of the species in this study are considered Least Concern and some of them are not even mentioned. The present study helps to know the problems and threats faced by wild animals and is the first work carried out in the region.

CAN HUMAN DEMOGRAPHIC OR BIOLOGICAL FACTORS INFLUENCE MAMMAL ROADKILL? A CASE STUDY IN THE GO-060 HIGHWAY

Roads cause several environmental impacts, such as roadkill of wild animals, which may result in the decrease of local fauna density. Roadkill occurs because roads intersect the habitats of many taxa, especially in fragmented landscapes, such as the Cerrado biome. The present study aimed to determine whether demographic variables or biological characteristics influence the mammal’s roadkill rate. A survey was conducted in the section of the GO-060 highway located between the municipalities of Trindade and Ipora, from April to September 2012, during the dry season. We used Kruskal-Wallis tests to investigate possible differences among roadkills per sector, species, order, food habit, and activity pattern. Pearson correlation was used to verify the association between roadkill rate and home range. The influence of body mass on the roadkill rate was estimated through a simple linear regression. To verify whether human demographic variables influence the roadkill, we used a multiple linear regression. We recorded 89 individuals of mammals during 18 field trips and obtained a roadkill rate of 0.025 individuals/km/day. Mammals with different food habits have different roadkill rates, once herbivorous mammals are less prone to be roadkilled than omnivorous and insectivorous species. Characteristics such as home range, body mass and activity patterns were not determinant of roadkill rates in this study. Similarly, human demographic variables did not influence the number of roadkills. Biological and ecological characteristics should be considered when implementing measures to reduce roadkill. Hence, it becomes clear that surveys of fauna roadkill should consider both human demographic and biological variables, once, in this research, none of them are relevant by itself, they can be considered complementary information, and can be used to support practical actions.

Influence of Landscape Factors on Amphibian Roadkills at the National Level

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.

Assessment of Rabies and Canine Distemper Viruses in Road-Killed Wildlife Mammals From the Semiarid Region of Northeastern Brazil

Road mortality due to collision with vehicles can affect many species, increasing the risk of local population decline or extinction. Infectious diseases that affect the central nervous system of wild animals may also promote an increase in road mortality due to the debilitating effects of blinding, neurologic disturbance, or behavior alteration. Roads in the surroundings of three conservation units in the Caatinga of Rio Grande do Norte, Brazil, were surveyed to identify which mammal species are being impacted by these anthropogenic structures. In addition, collected animals that were recently killed were also examined to determine their health status for diseases that affect the central nervous system (rabies and distemper virus) which cause neurological disorders. Between November 2014 and November 2015, 124 mammals from four potential reservoir species were found road-killed in the surveyed roads. Despite reports of these viruses circulating in Northeast Brazil, in both domestic and wild animal populations, none of the 18 road-killed mammals tested were infected by rabies or canine distemper, although some of the species identified are considered reservoirs for both diseases. This suggests that the animals most likely came from healthy populations or that the prevalence of these diseases is so low that it remained undetected. Furthermore, the high number of road-kills during this 1-year period indicates that mammal species from these conservation units are being negatively impacted, regardless of their health status. Hence, further studies must be conducted to identify other factors contributing to the road-killing of these species and implement the adequate mitigation measures to reduce or eliminate road mortality in the vicinities of these three conservation units.

Long-term monitoring by roadkill counts of mammal populations living in intensively cultivated landscapes

Elusive behaviour and financial constraints hamper the long-term monitoring of mammal population, particularly in intensively cultivated and urbanised landscapes, where most survey methodologies cannot be applied effectively. Provided that there is a direct relationship between each species’ density and frequency of road casualties, roadkill counts may represent a cost-effective alternative method to collect abundance data over long periods. We quantified the numbers of casualties of mammal species from 2001 to 2016 along two routes (65 km) crossing the heavily altered central River Po plain (N Italy). Each route was surveyed by car 10 times per month, covering 123,987 km and recording 15,589 road-kills from 15 species (15.3 roadkills/100 km/year). Most widespread mammals previously reported for the study area were recorded. Variation in each species’ roadkill numbers throughout the study period was consistent with available information on their distribution and abundance and the consistency of the patterns outlined on the two roads supported the hypothesis that the frequency of roadkills was related to each species’ density. Seasonal fluctuations in roadkill records could be related to either their reproductive cycles or dispersal patterns. For meso- and large species, the relationship between the occurrence of casualties and a set of 13 habitat variables was assessed by Logistic Regression Analysis. Based on our results, we believe that roadkill counts should be implemented to outline species’ population trends wherever high road density fragments wildlife habitats, and may represent a powerful citizen science-based method to collect large amounts of data over long periods.

Seasonal Variation in Wildlife Roadkills in Plantations and Tropical Rainforest in the Anamalai Hills, Western Ghats, India

Wildlife–vehicle collisions on the roads lead to mortality of a range of animal taxa both within and around wildlife reserves. Quantifying and understanding impacts of roads on wildlife mortality are essential for identifying vulnerable taxa and suitable mitigation measures. We studied animal mortality on roads in relation to habitat and season in the Anamalai Tiger Reserve and adjoining Valparai plateau in the Western Ghats, India. Habitats were broadly classified as forest, monoculture plantations (tea, coffee, eucalyptus) and mixed. Eleven road transects of 3–12 km length were surveyed between 9 and 12 times each during monsoon (2011) and summer (2012). We recorded 2969 roadkills (mean = 2.01/km) during the 1473.4 km of road surveys carried out. The overall roadkill rate was 21.2 (± 3.87 SE) individual kills/10 km. Amphibians were most frequent in roadkills (overall roadkill rate of 9.3 ± 2.17 SE kills/10 km, n = 1307), followed by invertebrates and unidentified taxa (7.6 ± 1.81 SE kills/10 km, n = 1066). Roadkill rate was 2.4 times higher in monsoon than summer, with amphibians particularly averaging higher kill rate during monsoon. Frequency of roadkills of various animal groups differed between seasons in different habitats. In both the seasons, most roadkills were recorded mainly in tea, forest, and forest–tea habitats. Relative to length of roads through forest, a disproportionately large number of roadkills of herpetofauna and mammals were recorded in forest habitat. Higher vehicular movements, including tourist traffic, road widening, removal of native plants along roads and construction of sidewalls without breaks obstruct animal movements and may be responsible for roadkills. Designing roads to be more permeable for safe animal movement, particularly where roads pass through forest, and sensitizing highways authorities are essential to reduce animal mortality and make roads more wildlife-friendly in this region.

Atropellamiento de vertebrados en tres tipos de carretera de la región montañosa central de Veracruz, México

Este estudio evalúa la influencia del tipo de carretera y de la infraestructura (obras de drenaje) sobre el número de vertebrados atropellados en la carretera Xalapa – Puebla (tramo: Banderilla – Amozoc) en la zona central montañosa del Estado de Veracruz. El estudio se realizó en tres diferentes tipos de carretera (que varían de acuerdo al número de carriles y tipo de estructura que los separa) en los cuales se seleccionaron sitios donde existiera una obra de drenaje considerada como paso potencial para la fauna. En cada uno de los sitios se contó el número de individuos atropellados y se relacionó con la presencia – ausencia de obras de drenaje, la pendiente del derecho de vía con respecto a la carretera, así como el tipo de carretera. Se encontró un mayor número individuos atropellados en la supercarretera seguido por la autopista dividida por barrera central vegetativa y la autopista con barrera central de muro de concreto, y no se detectó un efecto de la presencia de las obras de drenaje sobre el número de individuos atropellados. Además, se encontró una relación negativa entre el número de individuos atropellados y la inclinación del derecho de vía. Este estudio contribuye a entender los factores que limitan el paso de vertebrados en las carreteras y discute sobre las implicaciones de la planeación-construcción de la infraestructura vial en el contexto de la conservación de la fauna silvestre.

Porcupines (Erethizon dorsatum) in Arizona, 2011–2015

A five-year study to determine the status of the porcupine (Erithizon dorsatum) in the state of Arizona was conducted. Letters requesting the cooperation of several agencies and requesting the public to report any sighting of porcupines were gathered by staff and students of Eastern Arizona College. The main agency supporting this study was the Arizona Game and Fish Department. During the study 61 sightings were reported and the data from each report were analyzed to compare to previous studies by Taylor in the 1930s and Brown and Babb in 2007. Mountain lions appear to continue to be a limiting factor in controlling the population. The most significant factor documented in this study is the increase in the number of road kills. Taylor reported no road kills in the 1930s, Brown and Babb reported 21% of porcupines as road kills in 2007 and this study documented 41% as road kill. It is speculated that the increase in traffic along major highways and the slow pace of porcupines has increased this cause of death.

Factors affecting road mortality in birds

Several hundred million birds are killed on an annual basis worldwide due to collisions with vehicles.While this is well documented, less data exists on specific factors affecting thenumber of roadkills. I examined roadkill patterns while driving a car during a 44-month period (617 days, twice daily) along a 25 kmstretch of road in themiddle ofNorway. In total, 121 roadkills were detected during that period. I used information on bodymass, speed limit, vegetation in the vicinity, flight distance, abundance of birds in the surrounding environment and number of birds sitting on the road in order to elucidate their effects on the number of roadkills and susceptibility to become a roadkill for 30 different bird species/ groups of species. Roadkill numbers were highest in summer, and at certain parts of the road the mortality rate was much higher than in others. Heavier birds flew away from the approaching car at a longer distance than smaller birds, but they still had a relatively high mortality rate. Birds known to search for food on roads were more likely than other birds to become roadkill. Birds observed on the road explained a significant amount of the variation in roadkills between the species, in contrast to the abundance of birds in the surroundings. Fewer birds than expected were found where the speed limit was highest, and roadkilled birds were visible for a longer period when their body mass was higher.

Seasonal variation in vertebrate traffic casualties and its implications for mitigation measures

Wildlife mortality on roads is a global conservation problem. To implement a cost-effective programme of mitigation measures, it is essential to determine spatial and temporal patterns of traffic collisions. Identifying seasonal road-collision patterns could make it possible to schedule and optimize monitoring programmes. We evaluated seasonal variation in the roadkills of four vertebrate taxonomic groups (amphibians, reptiles, birds and mammals) across an environmental gradient in northeastern Iberia. Seven roads were monitored twice a month for one year and seasonal roadkill aggregations were examined using Poisson tests. Roadkill patterns were correlated with environmental variables using Generalized Linear Models. Amphibians were the group most commonly killed. Overall, the roadkill pattern was seasonal, and most roads showed seasonal peaks of casualties in autumn and spring. Roadkill peaks showed slightly seasonal differences between taxonomic groups. The total number of roadkill incidents was positively associated with temperature and negatively associated with solar irradiance. The roadkill numbers by group were related to different environmental factors: amphibian roadkills increased with relative humidity, while this relationship was negative for birds; mammal roadkills were associated with temperature, and reptile roadkills correlated with precipitation, solar irradiance, and temperature. Our results suggest that roadkill rates in Catalonia are seasonal and mostly associated with several climatic factors, although they can vary depending on taxonomic group and environmental factors. Our results highlight the fact that an understanding of seasonal variation in roadkills is critical for optimizing monitoring programmes and temporary mitigation measures aimed at particular species or taxonomic groups.

Avian trait-mediated vulnerability to road traffic collisions

Collision with vehicles is an important source of bird mortality, but it is uncertain why some species are killed more often than others. Focusing on passerines, we tested whether mortality is associated with bird abundances, and with traits reflecting flight manoeuvrability, habitat, diet, and foraging and social behaviours. We also tested whether the species most vulnerable to road-killing were scarcer near (<500m) or far (>500–5000m) from roads. During the breeding seasons of 2009–2011, we surveyed roadkills daily along 50km of roads, and estimated bird abundances from 74 point counts. After correcting for phylogenetic relatedness, there was strong correlation between roadkill numbers and the abundances of 28 species counted near roads. However, selectivity indices indicated that Blue tit (Parus caeruleus), Blackcap (Sylvia atricapilla) and European goldfinch (Carduelis carduelis) were significantly more road-killed than expected from their abundances, while the inverse was found for seven species. Using phylogenetic generalised estimating equations, we found that selectivity indexes were strongly related to foraging behaviour and habitat type, and weakly so to body size, wing load, diet and social behaviour. The most vulnerable passerines were foliage/bark and swoop foragers, inhabiting woodlands, with small body size and low wing load. The species most vulnerable to road collisions were not scarcer close to roads. Overall, our study suggests that traits provide a basis to identify the passerine species most vulnerable to road collisions, which may be priority targets for future research on the population-level effects of roadkills.

Factors Influencing Data Quality in Citizen Science Roadkill Projects

Factors Influencing Data Quality in Citizen Science Roadkill Projects

How many rodents die on the road? Biological and methodological implications from a small mammals’ roadkill assessment on a Spanish motorway

AbstractSome small mammal species use road verges as a habitat for sheltering. As a result, their populations suffer mortality from roadkill in an unknown extent. We analysed the road mortality of small mammals and the population impact of roadkill on wood mouse along 1 year on a 4‐km motorway stretch. To account for potential bias in carcass sampling, we conducted walking surveys with the traffic interrupted and we performed three carcass persistence experiments to estimate total number of roadkills. The estimations were contrasted with previous studies and the population abundance on the road verges. The spatial pattern and the effects of seasonality and traffic volume on roadkill were analysed. We recorded 84 rodent carcasses with a mean carcass persistence of 6.65 days (SE = 0.41). The estimations of roadkill ranged between 190.2 and 238.3 individuals km−1 year−1, with a mean value close to a monthly 6 % mortality for the most common specie. Roadkill was more frequent during the hottest and driest months, and showed a unimodal relation with traffic peaking at 8100 vehicles day−1. A spatial aggregation of roadkill was detected with 80–190 m clustering. Our results suggest that, although rodents suffer greater roadkill mortality than previously reported, it affects a small percentage of the wood mouse population in our study area. This source of mortality is unlikely to affect population viability in the short term. Our results show that roadkill surveys should be specifically designed for small mammals to have a more accurate analysis of the effects of roadkill on their populations.

Implications of upgrading a minor forest road on traffic and road-kill in southeast Queensland

The planned upgrade of a minor road in Brisbane connecting two suburbs through a forested area raised concerns about possible increases in road-kill in an area of high wildlife abundance and diversity. Extensive consultation with community representatives resulted in the incorporation of traffic calming devices in the design of the forested section of the road. To assess the effectiveness of these, road-kill surveys were carried out before and after the upgrade and vehicle numbers and speeds were obtained from traffic census data. Vehicle numbers almost doubled following the upgrade. The number of road-kills increased by a factor of three after the upgrade but there were marked differences for different sections of the road, with higher rates in suburban areas and lower rates in the forest section. The study supports previous work showing the importance of low speeds for reducing road-kill and showing that low speeds are best achieved by the inclusion of traffic calming devices in the road design.

Inter-individual variability of stone marten behavioral responses to a highway.

Efforts to reduce the negative impacts of roads on wildlife may be hindered if individuals within the population vary widely in their responses to roads and mitigation strategies ignore this variability. This knowledge is particularly important for medium-sized carnivores as they are vulnerable to road mortality, while also known to use available road passages (e.g., drainage culverts) for safely crossing highways. Our goal in this study was to assess whether this apparently contradictory pattern of high road-kill numbers associated with a regular use of road passages is attributable to the variation in behavioral responses toward the highway between individuals. We investigated the responses of seven radio-tracked stone martens (Martes foina) to a highway by measuring their utilization distribution, response turning angles and highway crossing patterns. We compared the observed responses to simulated movement parameterized by the observed space use and movement characteristics of each individual, but naïve to the presence of the highway. Our results suggested that martens demonstrate a diversity of responses to the highway, including attraction, indifference, or avoidance. Martens also varied in their highway crossing patterns, with some crossing repeatedly at the same location (often coincident with highway passages). We suspect that the response variability derives from the individual's familiarity of the landscape, including their awareness of highway passage locations. Because of these variable yet potentially attributable responses, we support the use of exclusionary fencing to guide transient (e.g., dispersers) individuals to existing passages to reduce the road-kill risk.

Do dry ledges reduce the barrier effect of roads?

Wildlife crossing structures combined with fencing seek to improve permeability and habitat connectivity across roads and reduce wildlife-vehicle collisions. However, the presence of water inside culverts can seriously limit their effectiveness. The implementation of dry ledges can be a good measure to allow crossing when flooded. So far, there is a lack of knowledge on the effectiveness of dry ledges combined with fencing for a wide diversity of vertebrates. The main goal of this study is to evaluate how the presence of dry ledge affect culvert use for Mediterranean mesocarnivores (red fox Vulpes vulpes, stone marten Martes foina, European badger Meles meles, European otter Lutra lutra and common genet Genetta genetta). Between January and March 2008, wooden dry ledges were placed in 15 of 32 surveyed culverts. Additionally 100meters of small mesh size and buried fences were installed along each side of all culverts. During one year we used video surveillance and track-plates to detect crossing events over seven consecutive nights per season in each monitored culvert. We evaluate the relative importance of dry ledges on culvert use and compare the number of road-kills within a 100m buffer radius around the culverts before and after fence installation and culverts that were never fenced (control culverts). Although different species responded to culvert features differently, the presence of dry ledges was the most relevant feature explaining crossing events, in particular, for stone martens and genets. The fencing used did not reduce mammals road-kill prevalence. Our results imply that in order to improve culvert use, road managers should take into account the placement of ledges on culverts that remain flooded most of the year (more than 3cm of water-depth). We also suggest exploring the role of ledge size and construction materials to increase the likelihood of being used by foxes and badgers.