Road mortality in freshwater turtles: identifying causes of spatial patterns to optimize road planning and mitigation

Road mortality of freshwater turtles can be high enough to imperil populations near roads, thus there is a need to efficiently and accurately locate regions of excessive road-kill along road networks for mitigation. Weekly over 2?years, we drove a 160?km highway circuit in northeastern New York State, USA and recorded the location of all detected road-kill of three freshwater turtle species (Chelydra serpentina, Chrysemys picta, Emydoidea blandingii). We then analyzed the spatial dispersion of road-kill and the road and landscape features associated with road-kill locations. Road-kill was most prevalent at a limited number of short road segments, termed ‘hotspots’. The locations of hotspots, as indicated by kernel density analysis, and the peak spatial extent of hotspots (250?m), as indicated by Ripley’s?K, corresponded to the locations and average lengths of causeways (road segments with wetlands within 100?m on both sides). Hotspots were located at causeways that were greater than 200?m length and characterized by high traffic volumes, close proximity to water, and high forest coverage. We conclude that freshwater turtle road mortality is spatially aggregated at short, severe hotspots, and hotspot locations can be predicted when the locations of wetlands, traffic volumes, and the land-uses bordering roads are known. Hotspot models using these predictors can locate sites along a road network that are the most promising for mitigation to reduce excessive road mortality and maintain connectivity.     

Demographic effects of road mortality on mammalian populations: a systematic review

In light of rapidly expanding road networks worldwide, there is increasing global awareness of the growing amount of mammalian roadkill. However, the ways in which road mortality affects the population dynamics of different species remains largely unclear. We aimed to categorise the demographic parameters in mammalian populations around the world that are directly or indirectly affected by road mortality, as well as identify the most effective study designs for quantifying population-level consequences of road mortality. We conducted a comprehensive systematic review to synthesise literature published between 2000 and 2021 and out of 11,238 unique studies returned, 83 studies were retained comprising 69 mammalian species and 150 populations. A bias towards research-intensive countries and larger mammals was apparent. Although searches were conducted in five languages, all studies meeting the inclusion criteria were in English. Relatively few studies (13.3%) provided relevant demographic context to roadkill figures, hampering understanding of the impacts on population persistence. We categorised five direct demographic parameters affected by road mortality: sex- and age-biased mortality, the percentage of a population killed on roads per year (values up to 50% were reported), the contribution of roadkill to total mortality rates (up to 80%), and roadkill during inter-patch or long-distance movements. Female-biased mortality may be more prevalent than previously recognised and is likely to be critical to population dynamics. Roadkill was the greatest source of mortality for 28% of studied populations and both additive and compensatory mechanisms to roadkill were found to occur, bringing varied challenges to conservation around roads. In addition, intra-specific population differences in demographic effects of road mortality were common. This highlights that the relative importance of road mortality is likely to be context specific as the road configuration and habitat quality surrounding a population can vary. Road ecology studies that collect data on key life parameters, such as age/stage/sex-specific survival and dispersal success, and that use a combination of methods are critical in understanding long-term impacts. Quantifying the demographic impacts of road mortality is an important yet complex consideration for proactive road management.     

Integrated risk factors for vertebrate roadkill in southern Ontario

Road mortality of animals (roadkill) threatens public safety and wildlife populations. As mitigation tools, predictive models of roadkill are becoming more common in the published literature; however, few models generalize across multiple taxa, and thus are less useful for management scenarios that account for multiple target species. Using a dataset of 653 vertebrate roadkills collected from 2 parks in southern Ontario, we constructed generalized linear mixed models to determine the simultaneous risk factors for bird, frog, mammal, five-lined skink (Eumeces fasciatus), snake, toad, and turtle hatchling roadkills from among a set of 8 potential predictor variables. Posted road speed limit was the dominant roadkill predictor (positive coefficient), followed by maximum daily temperature (positive), habitat diversity (positive), and distance from wetlands (negative). All else being equal, as road speed limits increase from 20 km/hr to 50 km/hr, the model predicted the season's mean roadkill probability for a given location to increase from less than 0.1 to 0.75. Conversely, roadkill probability declined from 0.55 to 0.29 as distance from wetland edges increases from 0 km to 1 km. Model diagnostics calculated from randomly resampled cross-validation datasets indicated that the best model formulation had an averaged predictive accuracy of 67.5% and an area under the curve (AUC) of 0.867. The best model also reflected seasonal patterns of animal behavior, including late-summer frog movements and fall turtle hatching events. The best model also compared favorably to single-taxon equivalent models. To reduce the incidence of vertebrate roadkill, we recommend that managers lower road speed limits, especially on roads near diverse habitats and near wetlands, and on warmer days if temporary signage is used. © 2012 The Wildlife Society.     

Road mortality of pond-breeding amphibians during spring migrations in the Mazurian Lakeland, NE Poland

The effects of road traffic mortality on amphibian populations are in many cases hard to estimate and speculate, primarily due to the inaccuracy of the methods employed in studies. We have analyzed amphibian road mortality during two breeding seasons on selected road sections adjoining spawning ponds and have critically reviewed methods used for estimating the impact of road traffic on migrating amphibians. The mortality rates of particular amphibian species differed significantly and varied according to year, site, and traffic volume. The highest mortality was recorded for Bufo bufo and the lowest for Lissotriton vulgaris. Species-specific parameter estimates of mortality, evaluated on a daily basis counts of roadkills, were positively correlated with the mean body mass of the amphibian species. The share of a given species among carcasses found on the road, commonly used in such studies, proved to be an unreliable measure of mortality. We found that nearly 60% of amphibian roadkill victims had disappeared within 24?h of exposure, and the number of missing carcasses was inversely related to body mass.     

Wildlife road traffic accidents: a standardized protocol for counting flattened fauna

Previous assessments of wildlife road mortality have not used directly comparable methods and, at present, there is no standardized protocol for the collection of such data. Consequently, there are no internationally comparative statistics documenting roadkill rates. In this study, we used a combination of experimental trials and road transects to design a standardized protocol to assess roadkill rates on both paved and unpaved roads. Simulated roadkill were positioned over a 1 km distance, and trials were conducted at eight different speeds (20–100 km·h⁻¹). The recommended protocol was then tested on a 100-km transect, driven daily over a 40-day period. This recorded 413 vertebrate roadkill, comprising 106 species. We recommend the protocol be adopted for future road ecology studies to enable robust statistical comparisons between studies.     

Methodologies for Surveying Herpetofauna Mortality on Rural Highways

Abstract: Road mortality can contribute to local and regional declines in amphibian and reptile populations. Thus, there is a need to accurately and efficiently identify hotspots of road-mortality for hazard assessment and mitigation. In 2002, we conducted walking and driving surveys throughout an extensive rural highway network in northern New York, USA, to evaluate survey methods and to quantify spatial and temporal patterns of herpetofauna road-mortality. In 2004, we repeated the surveys at a subset of locations to quantify interannual repeatability. Reptile and amphibian species had different peak periods of road-mortality because they differed in the causes of movements that resulted in crossings. Spatial locations of herpetofauna road-mortality were concentrated at a limited number of hotspots. Hotspots overlapped across species and were located at consistent locations across years. Results of walking and driving surveys were highly repeatable among survey teams, but driving surveys underestimated the density of road-mortality because many animals were missed. Detection failure was higher in some taxa (e.g., frogs) than others (e.g., turtles). Our results indicate that it is possible to design a valid, efficient methodology for locating hotspots of reptile and amphibian road-mortality along a road network and, thus, pinpoint priority sites for mitigation.     

Wildlife roadkill patterns in a fragmented landscape of the Western Amazon

One of the most evident and direct effects of roads on wildlife is the death of animals by vehicle collision. Understanding the spatial patterns behind roadkill helps to plan mitigation measures to reduce the impacts of roads on animal populations. However, although roadkill patterns have been extensively studied in temperate zones, the potential impacts of roads on wildlife in the Neotropics have received less attention and are particularly poorly understood in the Western Amazon. Here, we present the results of a study on roadkill in the Amazon region of Ecuador; a region that is affected by a rapidly increasing development of road infrastructure. Over the course of 50 days, in the wet season between September and November 2017, we searched for road‐killed vertebrates on 15.9 km of roads near the city of Tena, Napo province, for a total of 1,590 surveyed kilometers. We recorded 593 dead specimens, predominantly reptiles (237 specimens, 40%) and amphibians (190, 32%), with birds (102, 17%) and mammals (64, 11%) being less common. Recorded species were assigned to three functional groups, based on their movement behavior and habitat use (“slow,” “intermediate,” and “fast”). Using Ripley's K statistical analyses and 2D HotSpot Identification Analysis, we found multiple distinct spatial clusters or hotspots, where roadkill was particularly frequent. Factors that potentially determined these clusters, and the prevalence of roadkill along road segments in general, differed between functional groups, but often included land cover variables such as native forest and waterbodies, and road characteristics such as speed limit (i.e., positive effect on roadkill frequency). Our study, which provides a first summary of species that are commonly found as roadkill in this part of the Amazon region, contributes to a better understanding of the negative impacts of roads on wildlife and is an important first step toward conservation efforts to mitigate these impacts.     

Road avoidance and its energetic consequences for reptiles

Roads are one of the most widespread human‐caused habitat modifications that can increase wildlife mortality rates and alter behavior. Roads can act as barriers with variable permeability to movement and can increase distances wildlife travel to access habitats. Movement is energetically costly, and avoidance of roads could therefore impact an animal's energy budget. We tested whether reptiles avoid roads or road crossings and explored whether the energetic consequences of road avoidance decreased individual fitness. Using telemetry data from Blanding's turtles (Emydoidea blandingii; 11,658 locations of 286 turtles from 15 sites) and eastern massasaugas (Sistrurus catenatus; 1,868 locations of 49 snakes from 3 sites), we compared frequency of observed road crossings and use of road‐adjacent habitat by reptiles to expected frequencies based on simulated correlated random walks. Turtles and snakes did not avoid habitats near roads, but both species avoided road crossings. Compared with simulations, turtles made fewer crossings of paved roads with low speed limits and more crossings of paved roads with high speed limits. Snakes made fewer crossings of all road types than expected based on simulated paths. Turtles traveled longer daily distances when their home range contained roads, but the predicted energetic cost was negligible: substantially less than the cost of producing one egg. Snakes with roads in their home range did not travel further per day than snakes without roads in their home range. We found that turtles and snakes avoided crossing roads, but road avoidance is unlikely to impact fitness through energetic expenditures. Therefore, mortality from vehicle strikes remains the most significant impact of roads on reptile populations.     

Golden eagle use of winter roadkill and response to vehicles in the western United States

Vehicle collisions are a significant source of wildlife mortality worldwide, but less attention has been given to secondary mortality of roadkill scavengers, such as the golden eagle (Aquila chrysaetos). We sought to quantify golden eagle winter use of roadkill mammal carcasses and eagle flushing from vehicles in Oregon, Utah, and Wyoming, USA, as proxies for strike risk, using motion-sensitive cameras. We monitored 160 carcasses and captured 2,146 eagle–vehicle interactions at 58 carcasses (1–240 observations/carcass) during winters of 2016–2017, 2017–2018, and 2018–2019. We used generalized linear mixed models, which suggested that eagle use of carcasses declined with time since camera deployment but increased with distance to road. Flushing from vehicles decreased with carcass distance to road but was higher in the morning, in response to larger vehicles and vehicles in the closest lane, and in the Oregon study area. We suggest that roadkill distance to road is the easiest factor to manipulate with the dual benefits of increasing food availability to golden eagles and decreasing flush-related vehicle strike risk. We recommend that roadkill be moved at least 12 m from the road to increase eagle use and decrease flushing 4-fold relative to behavior observed at the road edge. Because flushing from roadkill is believed to be the primary cause of eagle–vehicle strikes, informed roadkill management has the potential to reduce human-caused mortality of golden eagles.     

Factors influencing the spatial patterns of vertebrate roadkill in South Africa: The Greater Mapungubwe Transfrontier Conservation Area as a case study

Few studies have investigated the factors that influence roadkill occurrence in developing countries. In 2013, we monitored a 100‐km section of the road (comprising the R572 and R521 regional highways and the D2662) that pass through the Greater Mapungubwe Transfrontier Conservation Area in South Africa, to assess the possible factors influencing roadkill. Over a period of 120 days, and across the three ecological seasons, we recorded 981 roadkills (rate = 0.08 roadkill/km/day) from four vertebrate taxonomic groups. We generated predictive models of roadkill from one combined data set that considered eight variables identified from the literature as potential correlates of roadkill. The model that included the distance of the fence from the road, habitat type adjacent to the road, and the presence of a hill in the road (i.e., elevation) or a bank on the side of the road best explained roadkill occurrence. More roadkill was predicted to occur in both open and dense mopane and dense mixed bushveld habitats, on a hill, when there was a bank on the side of the road, and as the distance between the road verge and a fence decreased. Our model provides some insight into the significant predictors of roadkill occurrence and is therefore a valuable tool in identifying sites of high‐potential roadkill frequency and formulating mitigation measures for reducing road mortalities.     

Identifying Hot Moments in Road-Mortality Risk for Freshwater Turtles

ABSTRACT Risk assessments can be used to identify threats, which vary both in space and time, to declining species. Just as hot spots describe locations where threat processes operate at a higher rate than in surrounding areas, hot moments refer to periods when threat rates are highest. However, the identification of hot moments can be challenging because the temporal complexity of some threat processes makes their effects on population viability difficult to predict. Declining throughout much of their range, Blanding's turtle (Emydoidea blandingii) populations are potentially most vulnerable to road mortality where road densities and traffic volumes are high. The temporal variations in road-mortality risk faced by these and other semiaquatic turtles at the population level are a consequence of several factors, including sex-specific movement characteristics and seasonal changes in traffic volume. We examined these risk factors for Blanding's turtle populations in Maine, USA, by integrating temporally explicit roadkill probabilities with demographic parameters informed by local and range-wide studies. Specifically, we used population simulations to estimate the relative risk for 14 2-week periods during the turtles’ active season. Our analysis clearly identified early summer as a period of elevated risk, with June through mid-July signaling a road-mortality hot moment for Blanding's turtles (for both M and F). These findings provide guidance for the implementation of temporally explicit conservation measures such as cautionary road signage, traffic management, and public outreach that, if timed strategically, could help to mitigate population impacts from road mortality.     

Differences in aquatic communities between wetlands created by an agricultural water recycling system

Establishment of an agricultural water recycling system known as the wetland reservoir subirrigation system (WRSIS) results in the creation of two different types of wetlands adjacent to agricultural fields. Each WRSIS consists of one treatment wetland designed to process agricultural contaminants (WRSIS wetlands) and one storage wetland for holding subirrigation water (WRSIS reservoirs). Previous WRSIS related research has focused on the filtration ability and development of aquatic plants within WRSIS wetlands. The fauna of the WRSIS reservoirs and how its aquatic community structure compares with WRSIS wetlands is unknown. We compared fish, amphibian, and reptile community structure between WRSIS wetlands and reservoirs in northwestern Ohio. Fishes, amphibians, and reptiles were sampled by seining, hoop netting, and gee minnow trapping in three WRSIS wetlands and three WRSIS reservoirs in June of 2006, 2007, and 2008. No difference in species richness, abundance, percent fish, percent reptiles, fish abundance, or reptile abundance occurred between the smaller shallower WRSIS wetlands and the deeper larger WRSIS reservoirs. Percent amphibians and amphibian abundance was greater in WRSIS wetlands than reservoirs. Jaccard’s index scores ranged from 0 to 0.5 and indicated species composition differed between WRSIS wetlands and reservoirs. Our results assisted with the development of design and management criteria incorporating wetland size, hydrology, and upland habitat intended to enable WRSIS wetlands to function primarily as amphibian habitat and the reservoirs to function as fish habitat.     

Contrasting road effect signals in reproduction of long- versus short-lived amphibians

Despite an increasing understanding of the effects of roadways on amphibian populations, no studies have examined road effects on demographic traits other than survival. We predicted that road mortality could exert a disproportionate effect on fecundity in long-lived species due to shifts in population age structures to younger individuals of smaller size that produce commensurately smaller egg masses. To test this hypothesis, we assessed egg mass sizes of a long-lived amphibian (spotted salamander, Ambystoma maculatum) and short-lived one (wood frog, Rana sylvatica) in wetlands near and far from highways. Egg mass sizes of A. maculatum were smaller in wetlands near highways. In contrast, those of R. sylvatica were similar among wetlands regardless of the distance from highways. We conclude that paved highways with moderate traffic volume may be having important effects on populations of long-lived amphibians through mortality-mediated depression of reproduction.     

Forest mammal roadkills as related to habitat connectivity in protected areas

Fragmentation of wildlife habitat by road development is a major threat to biodiversity. Hence, conservation and enhancement of habitat connectivity in roaded landscapes are crucial for effectively maintaining long-term persistence of ecological processes, such as gene flow and migration. Using multivariate statistical techniques combined with graph theoretical methods, we investigated the influence of road-crossing habitat connectivity and road-related features on roadkill abundance of forest mammals in protected areas of South Korea. Because species have different dispersal abilities and thus connectivity would differ between them, we explored three different groups of road-killed mammals, categorized as small, intermediate, and large ones. We found that in all three mammal groups, roadkills are increased on roads that intersect high-connectivity routes. Furthermore, the effect of habitat connectivity on roadkill abundance was scale-dependent. The roadkill abundances of small, intermediate, and large mammals were related with connectivity measured at scales ranging between 100 and 300 m, between 5 and 7 km, and between 10 and 25 km, respectively. Our finding with regard to scale-dependency highlights the importance of maintaining movement and connectivity across roads at multiple scales based on the dispersal potential of different species when planning conservation strategies for forest mammalian roadkill mitigation.     

Relative Effects of Road Risk,Habitat Suitability,and Connectivity on Wildlife Roadkills: The Case of Tawny Owls (Strix aluco)

Background

Despite its importance for reducing wildlife-vehicle collisions, there is still incomplete understanding of factors responsible for high road mortality. In particular, few empirical studies examined the idea that spatial variation in roadkills is influenced by a complex interplay between road-related factors, and species-specific habitat quality and landscape connectivity.

Methodology/Principal Findings

In this study we addressed this issue, using a 7-year dataset of tawny owl (Strix aluco) roadkills recorded along 37 km of road in southern Portugal. We used a multi-species roadkill index as a surrogate of intrinsic road risk, and we used a Maxent distribution model to estimate habitat suitability. Landscape connectivity was estimated from least-cost paths between tawny owl territories, using habitat suitability as a resistance surface. We defined 10 alternative scenarios to compute connectivity, based on variation in potential movement patterns according to territory quality and dispersal distance thresholds. Hierarchical partitioning of a regression model indicated that independent variation in tawny owl roadkills was explained primarily by the roadkill index (70.5%) and, to a much lesser extent, by landscape connectivity (26.2%), while habitat suitability had minor effects (3.3%). Analysis of connectivity scenarios suggested that owl roadkills were primarily related to short range movements (<5 km) between high quality territories. Tawny owl roadkills were spatially autocorrelated, but the introduction of spatial filters in the regression model did not change the type and relative contribution of environmental variables.

Conclusions

Overall, results suggest that road-related factors may have a dominant influence on roadkill patterns, particularly in areas like ours where habitat quality and landscape connectivity are globally high for the study species. Nevertheless, the study supported the view that functional connectivity should be incorporated whenever possible in roadkill models, as it may greatly increase their power to predict the location of roadkill hotspots.     

Carcass permanency time and its implications to the roadkill data

Roadkill studies are typically conducted without regard to the carcass permanency time on the highway, which may lead to underestimation of roadkill data, especially small animals that are quickly removed by scavengers. To evaluate the carcass duration time on the lane and its relation to the roadkill time event, we conducted an experiment comparing the removal rate of small carcasses between different stretches of a highway and stretches of dirt roads. The rates found in the study were considered high, with 89 % of carcasses being removed in the first 24 h and 66 % within 12 h. The removals were high for both road categories but reached their peaks at different periods of the day, being higher during the day on the highway and at night on dirt roads. We believe that removal on the highway is dictated by higher vehicular traffic and mainly by the action of scavenger birds during the day, while on dirt roads, it is due to the action of different opportunistic scavengers during the night.     

Factors influencing wolf <Emphasis Type="Italic">Canis lupus</Emphasis> roadkills in Northwest Spain

Roadkill is one of the most prominent causes of wildlife mortality. Much research effort has focussed on collisions with ungulates because of traffic safety. However, studies about large carnivore roadkills are scarce despite vehicles being a main cause of mortality. The absence of studies can be explained in part because of difficulties in obtaining sufficient sample sizes. We collected data from locations of 82 wolf roadkill sites in the Castilla y León Region, northwest Spain. We evaluated different models to characterise collision localities using logistic regressions with corrections for rare events. The best models included traffic and human disturbance parameters. Landscape variables did not improve predictive power. Fencing was a decisive key predictor; roadkill was proportionally higher along fenced highways than on similar major roads that lacked fences. Wolf–vehicle collisions were more common in agricultural areas, although wolf densities were lower in these zones. Both the higher density of important roads and a greater proportion of roaming wolves on the plateau may explain this pattern.     

Surveying Attitudes toward Reptiles on Roads: Questionnaire Responses Do Not Directly Translate to Behavioral Action

Roads pose significant threats to reptiles, and understanding the varying perceptual biases of motorists to different taxa may help determine management strategies for urban roads around important refuges such as wetlands. We surveyed Western Australian motorists online, asking them to rank their degree of concern for animal welfare, vehicle damage, and personal safety when hypothetically involved in a vehicle collision with 10 different animal taxa, including reptiles. Respondents also ranked their rescue likelihood for these taxa. We then observed motorist responses to snakes and lizards in the field, where we placed rubber models and controls on the shoulder of an urban road bordering a wetland in Perth, Western Australia. We also estimated the probability of a reptile being struck while crossing the study road at two different road vehicle densities. The online survey respondents claimed high mean concern for the welfare of animals on roads (M = 8.02 ± 2.73 SD out of 10) and low concern for vehicle damage (M = 2.87 ± 2.75) and personal safety (M = 2.91 ± 2.88). Respondents also claimed high mean rescue likelihood (M = 7.06 ± 3.40). In contrast, motorists observed in the field generally ignored objects, including reptiles, on the roadside (79% of n = 1,500). There were no observed intentional strikes on reptiles, one motorist made a rescue attempt (bobtail lizard), and all other responses were to slow down or move away from the treatment. Estimates of strike probability for a reptile crossing the study road at a low traffic volume (2.23 vehicles·min^-1) was > 75% for slow-moving (1 m·min^-1) reptiles, but reduced to ≤ 16% if they were moving quickly (60 m·min^-1). Although motorists did not intentionally strike model reptiles, surveyed attitudes did not directly translate to behavioral action, and crossing a road is risky for an urban reptile.     

Amphibian and reptile biogeographic regions of Northern Eurasia,mapped separately

Distributions of amphibian and reptile faunas were separately delimited on a 1:20 000 000 vegetation map of Northern Eurasia divided into 245 10-degree-longitudinal segments of native subzone within the USSR borders as of 1990. All reptile and amphibian species recorded in every segment were listed, and the Jaccard indices were calculated, and the similarity matrix was studied with cluster analysis. Hierarchic classifications were made: the amphibian one consisting of 3 faunistic regions, divided into 4 subregions, 7 biologic provinces, and 23 districts. The reptile classification includes 4 faunistic regions, 7 subregions, 18 provinces, and 14 districts. The reptile classification has 1.5 times more provincial and district subdivisions than amphibian one. Environmental factors correlating with faunistic nonuniformity were revealed. Our amphibian and reptile schemes are 1.9 and 3.5 times more informative than those proposed earlier and account for 75 and 91% of variance in the faunal similarity coefficient of specific areas, respectively (multiple correlation coefficients 0.87 and 0.95). Environmental factors can explain 84 and 93% of faunistic nonuniformity (correlation coefficients 0.95 and 0.96).     

Identification methods and deterministic factors of owl roadkill hotspot locations in Mediterranean landscapes

Road fatalities are among the major causes of mortality for Strigiformes species and may affect the population’s survival. The use of mitigation strategies must be considered to overcome this problem. However, because mitigation along the total length of all roads is not financially feasible, the locations where Strigiformes roadkills are more frequent (i.e., road fatality hotspots) must be identified. In addition to hotspot identification, factors that influence the occurrence of such fatalities should be recognized to allow mitigation measures to be delineated. We used road fatality data collected from 311 km of southern Portugal roads over a 2-year period to compare the performance of five hotspot identification methods: binary logistic regression (BLR), ecological niche factor analysis (ENFA), Kernel density estimation, nearest neighbor hierarchical clustering (NNHC), and Malo’s method. BLR and ENFA modelling were also used for recognizing roadkill deterministic factors. Our results suggest that Malo’s method should be preferred for hotspot identification. The main factors driving owl roadkillings are those associated with good habitat conditions for species occurrence and specific conditions that promote hunting behavior near roads. Based on these factors, several mitigation measures are recommended.