Ungulate-vehicle Collisions Research Articles

Olfactory repellents decrease the number of ungulate-vehicle collisions on roads: Results of a two-year carcass study

An experimental study was conducted to test the effectiveness of olfactory repellents (ORE) as a mitigation measure to reduce ungulate-vehicle collisions (UVC). In the first phase, an extensive field survey was undertaken while employing the Before-After Control-Impact (BACI) study design. On the basis of ungulate mortality, 134 road sections were monitored on foot along both roadsides once a week. The monitoring lasted fourteen weeks per year in both 2021 (Before period) and 2022 (After period). In the after period, 2022, ORE were applied within the impact segments. The second phase consisted of data verification and statistical analysis. The data revealed a decrease in UVC of 68%. The confidence interval of this estimate suggested, however, a great deal of uncertainty about the true value. Therefore, the data were pooled, and the Bayesian inference was applied. On the level of moderate evidence, ORE decreased the number of UVC by at least 43% and at most 60%. We also observed that the ORE effect was more pronounced in the first seven weeks after installation than in the following seven weeks, suggesting ungulate habituation to ORE. We have therefore concluded that for a short period (ideally corresponding to UVC peaks) ORE could be considered an effective safety measure for secondary roads.

Dead mammal walking: A month‐long march by a bison (Bison bison) after an ungulate–vehicle collision

AbstractGlobally, ungulate–vehicle collisions (UVCs) are a major human safety concern and may also represent a significant source of mortality for some ungulate populations. However, records of UVC based on counts of roadside carcasses or reports by drivers involved in these incidents are assuredly underestimated because not all ungulates struck die immediately or at the roadside or are reported by drivers or authorities. Here, we provide an observation and analysis of the movements of a GPS‐collared bison (Bison bison) that was involved in a UVC on the Alaska Highway and died in a thick boreal forest 29 days later. During that time, she moved 49.7 km from where she was hit. Her daily movement rate (in kilometers per hour) and daily net displacement (in kilometers per day) were significantly greater in the 29‐day period before she was struck compared with 29 days afterward. This vivid example illustrates that individuals injured in a UVC can die several weeks later and at a considerable distance from where they were initially struck. Moreover, when they eventually die, it may be where their carcass would not be found or associated with a UVC. Bison are the largest land mammal in North America and perhaps more robust to some lower impact UVC than smaller bodied species. Even so, if not for the GPS collar on this bison, we would have never known the fate of this individual, and the carcass likely never found. Taken together, the movements and final resting place of this bison illuminate how estimates of mortality as a result of UVC can be underestimated when the animal does not die immediately and in a location where it can be found. Given our data, we further urge managers to consider roadside counts of animals killed in UVC as a minimum estimate when considering options for mitigation.

Targeted recreational hunting can reduce animal-vehicle collisions and generate substantial revenue for wildlife management agencies

Reduction of conflicts arising from human-wildlife interactions is necessary for coexistence. Collisions between animals and automobiles cost the world's economy billions of dollars, and wildlife management agencies often are responsible for reducing wildlife-vehicle collisions. But wildlife agencies have few proven options for reducing wildlife-vehicle collisions that are effective and financially feasible at large spatiotemporal scales germane to management. Recreational hunting by humans is a primary population management tool available for use with abundant wild ungulates that often collide with automobiles. Therefore, we tested how well policies designed to increase human hunting of deer (longer hunting seasons and increased harvest limits) reduced collisions between white-tailed deer and automobiles along 618 km of high-risk roadways in Indiana, USA. We used a 20-y dataset that compiled >300,000 deer-vehicle collisions. Targeted recreational hunting decreased deer-vehicle collisions by 21.12 % and saved society up to $653,756 (95 % CIs = $286,063–$1,154,118) in economic damages from 2018 to 2022. Potential savings was up to $1,265,694 (95 % CIs = $579,108–$2,402,813) during the same 5-y span if relaxed hunting regulations occurred along all high-risk roadways. Moreover, license sales from targeted hunting generated $206,268 in revenue for wildlife management. Targeted hunting is likely effective in other systems where ungulate-vehicle collisions are prevalent, as behavioral changes in response to human hunting has been documented in many ungulate species across several continents. Our methods are attractive for management agencies with limited funds, as relaxed hunting regulations are relatively inexpensive to implement and may generate substantial additional revenue.

The Impact of Roadkill on Cervid Populations in Lithuania

Cervid roadkill, including moose, red deer and roe deer, can pose a risk to drivers and are frequently registered. However, the roadkill influence on overall cervid populations is not fully known, especially by roadkill that are not officially registered. The aim of this study was to assess the impact of cervid roadkill on population abundance, evaluating (i) the proportion of ungulate–vehicle collisions not registered by official bodies, (ii) the number of roadkill in relation to hunted animals and (iii) the proportion of roadkill that occurs in forest habitat. The number of unreported roadkill was calculated based on a roadkill index assessed during 3815 registration sessions on main and national roads in Lithuania from 2002–2022. During this period, 373 moose, 712 red deer and 9179 roe deer roadkill were unreported, correlating to 13.8%, 95.8% and 31.1% of those registered by the Traffic Supervision Service. In conclusion, 39.5%, 17.5% and 20.1% of roadkill were registered on roads through forests. Moose roadkill amounted to a figure corresponding to 10% of those hunted, with the same figure for red deer being 1.8%, neither adding much mortality. At 16.5%–16.6%, the figure for roe deer might be important.

Landscape and population drivers of ungulate-vehicle collisions in Portugal

Ungulate-vehicle collisions (UVC) have been steadily increasing throughout Europe, posing a risk to human safety, representing an extra factor of animals death. Here, we used information of a 2-year roadkill (2019–2020) monitoring of wild ungulates (wild boar, red deer and roe deer) to assess the drivers that influence the likelihood of UVC in Portugal. Our results support the contention that the variables promoting the collisions varied markedly between species, including the importance of land use and cover (wild boar and red deer), water availability and movement corridors (wild boar), ungulate population density (wild boar) and road topology (wild boar, red deer and roe deer) in the likelihood of UVC. The significant and positive interaction between urbanized and forest areas shows that regions sharing characteristics of both urban and natural environments represent a high-risk for the occurrence of collisions. The application of mitigation actions in these regions are welcome and should focus on reducing its attractiveness and/or the abundance of ungulate populations. Awareness campaigns and species-specific signalling may also contribute to a general decrease of casualties. We advocate that continued efforts of data collection are pivotal to assess the local relevance of fine-scale predictors amenable to manage.

Impact of Road Fencing on Ungulate–Vehicle Collisions and Hotspot Patterns

The number of road traffic accidents decreased in Lithuania from 2002 to 2017, while the ungulate–vehicle collision (UVC) number increased and accounted for approximately 69% of all wildlife–vehicle collisions (WVC) in the country. Understanding the relationship between UVCs, traffic intensity, and implemented mitigation measures is important for the assessment of UVC mitigation measure efficiency. We assessed the effect of annual average daily traffic (AADT) and wildlife fencing on UVCs using regression analysis of changes in annual UVCs and UVC hotspots on different categories of roads. At the highest rates, annual UVC numbers and UVC hotspots increased on lower category (national and regional) roads, forming a denser network. Lower rates of UVC increase occurred on higher category (main) roads, forming sparser road networks and characterized by the highest AADT. Before 2011, both UVC occurrence and fenced road sections were most common on higher-category roads. However, as of 2011, the majority of UVCs occurred on lower-category roads where AADT and fencing had no impact on UVCs. We conclude that wildlife fencing on roads characterized by higher speed and traffic intensity may decrease UVC numbers and at the same time shifting UVC occurrence towards roads characterized by lower speed and traffic intensity. Wildlife fencing re-allocates wildlife movement pathways toward roads with insufficient or no mitigation measures.

No clear effect of odour repellents on roe deer behaviour in the vicinity of roads

Ungulate–vehicle collisions pose a traffic safety issue as well as wildlife‐conservation issues in many countries. While fences are recommended as reliable safety measures for motorways and other high‐traffic volume roads, no generally accepted measures of the same efficiency are available for secondary roads. Odour repellents are applied in many central European countries, but contradictory results are available concerning their efficiency. We tested the effect of odour repellents on both a crossing frequency and the presence near roads of six individuals of roe deer over a period of five months (April–August 2019). The odour repellents were installed along two secondary roads, and along two semi‐open habitats (forest–meadow and forest–arable land) alternately, in several phases. Two hypotheses were tested. The first one focused on the change in animal presence close to the profiles where the odours were applied, while the second hypothesis concerned a change in the number of crossings of the same profiles. The results demonstrate that no clear effect of odour repellents on roe deer behaviour in both hypotheses were obtained. Apart from the obtained results, we discuss the importance of the methodology. We conclude that this kind of study design is extremely sensitive to a number of factors with a potentially negative influence on the course of the study design.

Correction to: Strength of correlation between wildlife collision data and hunting bags varies among ungulate species and with management scale

Most European ungulate species are increasing in numbers and expanding their range. For the management and monitoring of these species, 64% of European countries rely on indirect proxies of abundance (e.g., hunting bag statistics). With increasing ungulate numbers, data on ungulate-vehicle collisions (UVC) may provide an important and inexpensive, complementary data source. Currently, it is unclear how bag statistics compare with UVC. A direct comparison of these two indices is important because both are used in ungulate management. We evaluated the relationship between UVC and ungulate hunting bags across bioclimatic, regional, and local scales, using five time lags (t−3 to t+1) for the five most common wild ungulate species in Sweden. For all species, hunting bags and UVC correlated positively, but correlation strength and time lags varied across scales and among species. The two indices correlated most strongly at the local management scale. Correlation between both indices was strong for the smaller deer species and wild boar, in particular, but much weaker for moose where we found the best fit using a 2-year time lag. For the other species, indices from the same year correlated best. We argue that the reason for moose data behaving differently is that, in Sweden, moose are formally managed using a 3-year time plan, while the other species are not. Accordingly, moose hunting bags are influenced more strongly by density-independent processes than bags of the other species. Consequently, the mismatch between the two indices may generate conflicting conclusions for management depending on the method applied.

Strength of correlation between wildlife collision data and hunting bags varies among ungulate species and with management scale

Most European ungulate species are increasing in numbers and expanding their range. For the management and monitoring of these species, 64% of European countries rely on indirect proxies of abundance (e.g., hunting bag statistics). With increasing ungulate numbers, data on ungulate-vehicle collisions (UVC) may provide an important and inexpensive, complementary data source. Currently, it is unclear how bag statistics compare with UVC. A direct comparison of these two indices is important because both are used in ungulate management. We evaluated the relationship between UVC and ungulate hunting bags across bioclimatic, regional, and local scales, using five time lags (t−3 to t+1) for the five most common wild ungulate species in Sweden. For all species, hunting bags and UVC correlated positively, but correlation strength and time lags varied across scales and among species. The two indices correlated most strongly at the local management scale. Correlation between both indices was strong for the smaller deer species and wild boar, in particular, but much weaker for moose where we found the best fit using a 2-year time lag. For the other species, indices from the same year correlated best. We argue that the reason for moose data behaving differently is that, in Sweden, moose are formally managed using a 3-year time plan, while the other species are not. Accordingly, moose hunting bags are influenced more strongly by density-independent processes than bags of the other species. Consequently, the mismatch between the two indices may generate conflicting conclusions for management depending on the method applied.

Temporal patterns of ungulate-vehicle collisions in Lithuania

Wildlife mortality caused by vehicles is a serious conservation and economic problem as collisions with large mammals are global, pervasive and increasing. We analysed 14,989 reports of ungulate-vehicle collisions (UVC) that occurred in Lithuania from 2002 to 2017. We analysed UVC data for four major ungulate species (roe deer, red deer, moose and wild boar) and checked for potential seasonal or daily trends. The temporal distribution of collisions was species-dependent. UVC analysis showed strong monthly and hourly pattern. Most occurrences took place before or during sunrise (dawn) and after or during sunset (dusk) during the year. In spring, the highest UVC peaks occurred early in the morning and late in the evening, while in winter these peaks occurred in late mornings and early evenings. With most UVC occurring on Fridays, daily variations were weak. We conclude that temporal variations of UVC distributions are result of a complex interaction of phenological factors and animal behaviour. The information provided in this study reinforces the knowledge on the dynamics and patterns of UVC and represents an important element for the identification of mitigation measures. Our findings suggest that efforts to reduce UVC should also focus on driver attitudes considering the seasonal and daily variations in UVC.

Ungulate-vehicle collision risk and traffic volume on roads

We analyzed data from traffic counters installed on 143 Czech roads (motorways and primary roads) which precisely indicated current traffic volume during occurrences of ungulate-vehicle collisions (UVC). One thousand nine hundred ninety-five UVCs were identified over the period 2009–2015 on these 143 road segments. The overall range of annual average daily traffic (AADT) values, for the respective roads, was between 1547 and 78,320 AADT (vehicles/day). Almost 80% of UVC took place at volume lower than 1000 vehicles/h. We demonstrate that traffic volume has a different distribution during the day when compared with UVC distribution. The highest relative risk of UVC was identified for traffic up to 750 vehicles/h. The risk of UVC varied over the course of the year as it was influenced by ungulate locomotory activity. We concluded that the AADT, representing average annual daily traffic, does not accurately represent the actual traffic volume which is present during the night hours, where the majority of UVC usually occur. Therefore, there is a danger that UVC risk modeling, relying on AADT, will be distorted.

Temporal patterns of ungulate-vehicle collisions in a sparsely populated country

Ungulates (mainly Cervidae and wild boar Sus scrofa) are considered among the most problematic wildlife suffering on roads and causing the largest material losses due to high densities of ungulate populations, spatial and temporal movement patterns, and body size of these animals. Roe deer–vehicle collision (RDVC) as the most usual cause of ungulate fatality on roads may be applied as an appropriate model for understanding ungulate-vehicle collision patterns in general. To better understand, manage, and mitigate RDVCs, a detailed knowledge of the temporal behavioral patterns of roe deer is essential. In order to determine the role roe deer behavior plays in RDVCs, we examine time-dependent patterns of RDVCs in Lithuania, a country with a relatively low human population density and less developed transport infrastructure compared with other European countries with relatively high human population density and more intensive road network. Our analysis includes 5556 RDVC records from 2013 to 2016 and examines both short-term and long-term periods to determine the interrelationship between roe deer behavior and vehicle collisions. Our results document the relationship between RDVCs and season of the year with the highest RDVCs peaks occurring in late spring (May, 817, 14.7% of RDVC) and late autumn (November, 626, 11.3%). The daily RDVC frequency is influenced by seasonal changes in sunrise, sunset, and timing of twilight and the impact of these environmental variables on vehicle operator behavior. Our findings are comparable with those reported elsewhere in Europe and suggest that roe deer temporal behavioral patterns influence RDVCs more than transport infrastructure.

Endoparasite diversity of the main wild ungulates in Portugal

Wild ungulates have expanded their geographical range across Europe and Portugal is no exception. Despite the known benefits associated with the increase of these populations (e.g. increased prey for wild carnivores), the negative impacts also need to be taken into account (e.g. damages in agriculture and forestry, ungulate–vehicle collisions). Additionally, their role as reservoirs of zoonotic agents has gained scientific relevance due to the potential human health risks, impact on livestock and food safety. In northeast Portugal, Montesinho Natural Park, three species of ungulates occur in sympatry, the wild boar Sus scrofa, the red deer Cervus elaphus and the roe deer Capreolus capreolus. Considering their close association with humans and livestock, it is essential to understand their role as reservoirs of infectious diseases, namely as vectors for parasitic infections. In order to achieve this, 112 fresh faecal samples were collected to assess, by means of coprological analyses, their parasite diversity, prevalence and mean intensity. In total, 88 (78.60%, ±69.81–85.76) samples were infected with at least one parasite species. Parasite prevalence was different among the three species, with the red deer showing higher prevalence values (83.6%), then the wild boar (80.2%) and the roe deer (46.7%). The results have revealed that these species carry parasites that not only represent a health problem for domestic ruminants and domestic pigs (e.g. Muellerius sp., Trichostrongylidae, Strongylidae, Metastrongylus sp., Moniezia benedeni, Eimeria spp. and Cystoisospora sp.) but they can also pose a potential public health risk (e.g. Balantidium coli). The implementation of surveillance programs must include regular monitoring protocols of wild ungulates.

Roadside vegetation influences clustering of ungulate vehicle collisions

The aim of this study was to identify landscape-related factors which could explain the concentration of traffic crashes with large ungulates in a forest environment. We worked with ungulate-vehicle collisions which took place on the Czech road network in the period 2014–2016 using the application Srazenazver.cz. With the KDE+ method, we chose the most significant hotspots with linkage to forest. For comparison we randomly selected control localities outside the KDE+ hotspots (i.e., with very low level of ungulate-vehicle collisions) but still in the forest area. A set of photos were taken at each hotspot and control locality (2 orthophotos and 4 driver views). Each set of images was then visually analysed by two independent evaluators. They did not know which set of images were for hotspots and which set of images were for control localities. From the point of view of the overall score, it cannot be said that these two groups of locations differ (p-value 0.3575, Kolmogorov-Smirnov test). The only attribute that demonstrated a difference between hotspots and randomly selected locations was “attractiveness (quality food source and cover) of the immediate vicinity of the transport infrastructure for the ungulates” (p-value 0.0016, Kolmogorov-Smirnov test). Results confirm the importance of landscape management in the surroundings of transport infrastructure, especially in its immediate vicinity. However, they did not confirm the possibility that the most dangerous locations from the UVC point of view could be identified on the basis of landscape composition and the overall state of vegetation around transport infrastructure.

Application of KDE+ software to identify collective risk hotspots of ungulate-vehicle collisions in South Tyrol, Northern Italy

This paper is the first dealing with animal-vehicle collisions (AVC) with red and roe deer in South Tyrol, Northern Italy. The Autonomous Province of Bolzano (South Tyrol) has been collecting AVC data since 2012 on the entire provincial road network. Each year, AVC data accounted for more than 700 cases per year, with several socioeconomic and ecological implications. The aim of this research is to identify the locations where AVC occur more frequently than expected (hotspots) and better outline subsequent implementation of mitigation measures. For an effective identification of AVC hotspots, we applied a combined methodology of temporal and spatial analysis on AVC data collected on the South Tyrol road network in the years 2012–2014. AVC data enabled the identification of the temporal patterns, which showed different behaviors of the two target species in close proximity of the road network and throughout the 12 months. The KDE+ software applied to the 2012–2014 AVC database allowed for spatial analysis and the identification of hotspots, i.e., the road sections having the highest risk for drivers. The integration of the results, coming from the abovementioned methodologies, contributes to a detailed assessment of roads that would allow the identification of the local contributing factors and a base-line of potential problematic areas that will highlight the need for further investigation to assess whether the risk-rank is accurate and allocate effectively limited resources to a feasible number of identified hotspots and reduce the current degree of AVC in the South Tyrolean road network.

The effect of traffic intensity and animal activity on probability of ungulate-vehicle collisions in the Czech Republic

Traffic infrastructure and its traffic flows has rapidly developed in recent decades. This development brings benefits to society, but on the other hand has many negative impacts on the environment. Among the most significant impacts of road traffic is direct mortality of free-ranging animals due to vehicle collisions.The main aim of this study was to compare the significance of traffic intensity fluctuation and ungulate behavioural patterns with the probability of ungulate-vehicle collisions (UVCs) occurrence in the Czech Republic. Our research question was whether the probability of UVC occurrence is influenced mainly by vehicle traffic related factors (traffic intensity, road types) or by ungulate locomotory activity.We used information on UVCs from 2011 to 2013. We used Spearman’s rank ρ correlation coefficients to examine relationships between UVCs and traffic intensity fluctuation, and between UVCs and the locomotory activity of red deer and wild boar during 24-h cycles in respective months.The results indicate that the traffic intensity is not always the main factor causing the UVCs. A thorough analysis of our data showed that the main peaks of UVCs occur at time when animals have the highest locomotory activity. Our study proves high negative correlation between traffic intensity fluctuation and UVCs on motorways and expressways, which means ungulates tend to avoid crossing roads at peak traffic intensity. Next our study clearly shows that locomotory activity of ungulates is a more important factor in probability of UVC incidence than traffic intensity in the case of first-, second-, third-class roads and other roads.

Traffic mortality of four ungulate species in southern Finland

Ungulate–vehicle collisions are intensively studied in many countries. However, limited knowledge exists on how many animals struck actually die due to collisions and whether differences in traffic mortality occur between species living in the same area. In this study, we estimated a kill rate (the proportion of individuals killed/struck) and, in relation to their winter population sizes, the collision and traffic mortality rates for four ungulate species (moose Alces alces, white-tailed deer Odocoileus virginianus, roe deer Capreolus capreolus, and fallow deer Dama dama). We used an unofficial collision register collected between 2001 and 2012 (a total of 12 years) by voluntary hunters from the Hyvinkää Game Management Area (323 km2) located in southern Finland. The population estimates used were based on annual snow track censuses. A total of 497 ungulates were involved in collisions during the study period. Of these, 76% were killed directly or put down afterwards. Roe deer had the highest kill rate; 95% of struck individuals died. White-tailed deer had the highest collision and traffic mortality rates (8.0% and 6.5% of the winter population, respectively), followed by moose (6.5 % and 4.5%), roe deer (3.9% and 3.7%), and fallow deer (3.2% and 2.1%). As we found the collision and traffic mortality rates to be unequal between species, we recommend separately reporting all ungulate species when compiling collision statistics. We additionally suggest that local managers should be aware of ungulate collision and traffic mortality rates in their areas and should use this knowledge when planning annual harvest.

Ungulate vehicle collisions in a peri-urban environment: consequences of transportation infrastructures planned assuming the absence of ungulates.

Ungulate vehicle collisions (UVC) provoke serious damage, including human casualties, and a large number of measures have been developed around the world to avoid collisions. We analyse the main factors involved in UVC in a road network built in the absence of ungulates, where mitigation structures to avoid UVC were not adequately considered. Ungulate population greatly increased during the last two decades and now Roe Deer and Wild Boars are widely distributed over the study area, but even after this increase, the road network was not adapted to avoid UVC. A total of 235 Roe Deer (RDVC) and 153 Wild Boar vehicle collisions (WBVC) were recorded between January 2008 and December 2011. We randomly selected 289 sample points (87 RDVC, 60 WBVC and 142 controls) separated by at least 500 metres from the next closest point and measured 19 variables that could potentially influence the vehicle collisions. We detected variations in the frequency of RDVC on a monthly basis, and WBVC was higher at weekends but no significant differences were detected on a monthly basis. UVC were more likely to occur at locations where sinuosity of the road, velocity, surface of shrub and deciduous forest area were greater, the presence of fences entered with positive relationship and distance to the nearest building was less. RDVC were more likely to occur at locations where timber forest area increased and distance to the nearest building decreased and WBVC was related to open fields cover and also to the presence of fences. Sinuosity and velocity entered in both cases as significant factors. Major roads, in which the traffic volume is greater and faster, caused more accidents with ungulates than secondary roads. Nowadays, the high frequency of ungulate road-kills deserves a new strategy in order to adapt infrastructure and adopt mitigation measures.

Temporal patterns of ungulate-vehicle collisions in a subalpine Italian region

Over the last few decades, in Italy as in the rest of EU, both the number of wild ungulates and the volume of traffic have increased significantly. Consequently, ungulate-vehicle collisions have increased with significant costs in human death and injury, animal welfare and material damage. In this study we provide information about temporal patterns of collisions in a subalpine Italian region. We analyzed 1110 reports of accidents that occurred in Cuneo district from January 2008 to December 2011. Most of them were caused by roe deer and wild boar, while red deer, fallow deer and chamois were occasionally involved. Monthly distribution of accidents showed two peaks, with a higher risk of collision during spring mainly related to roe deer and a secondary peak in autumn caused by wild boar. No evident daily variations were noticed. In the case of roe deer, we reported the existence of a primary hourly peak at dusk and another secondary peak at dawn. Wild boar were most frequently involved in collisions during dusk and night. We hypothesized that these temporal distributions are the result of a complex interaction of phenological, behavioral and human-related reasons. Information provided in this study allows us to better understand the dynamics and patterns of wildlife-car collisions and represents an indispensable element for the implementation of any mitigation strategy.

Spatiotemporal analysis of vehicle collisions involving wild boar and roe deer in NW Spain

Ungulate–vehicle collisions pose a serious traffic safety hazard in the North of Spain. The understanding of underlying temporal and spatial structure of these non-random events is imperative to develop appropriate mitigation measures. This study analyses the temporal, spatial and spatiotemporal patterns of car crashes involving wild boar and roe deer in the province of Lugo (NW Spain) in the period 2006–2010 using geographic information systems (GIS) and spatial statistics. The temporal analysis – conducted at three scales: daily, weekly and seasonal – revealed that accidents are related to specific animal's life cycles and to interactions with human activities. The localization of collision points with GIS discovered the sections of the autonomic road network where accidents with the two studied species concentrate. Besides, the spatial arrangement of significant hotspots was mapped through kernel density estimation over two time scales (daily and seasonal), distinguishing among 41 sets, sequentially arranged to facilitate clustering comparison and determination of spatiotemporal risky areas. This work is of valuable help for road managers to design the appropriate mitigation measures that will improve traffic safety and animal welfare.