Data on wild mammals run over along roads in Osijek–Baranja County and much of eastern Croatia have not been available so far. Accurate records of roadkill in Croatia have been available only for large carnivores such as the brown bear,
Ursus arctos L., 1758 (Carnivora: Ursidae), the grey wolf,
Canis lupus L. 1758 (Carnivora: Canidae) and the Eurasian lynx,
Lynx lynx (L., 1758) (Carnivora: Felidae) [
3,
5,
6,
7]. More recent data include the roe deer,
Capreolus capreolus L., 1758 (Artiodactyla: Cervidae) and
S. scrofa in the Dinaric area [
28]. There were no accurate records of other run over mammals in Croatia until 2017 [
13]. Accurate records in Croatia mainly focus on large game and often aim to document vehicle damage for compensation purposes. The Road Traffic Safety Bulletin of the Ministry of the Interior of the Republic of Croatia only recorded incidents of vehicle collisions with animals without specifying if they were wild or domestic [
13]. Since 2017, due to no institution in Croatia keeping records of collisions with wild game, the Croatian Hunting Association has begun collecting data in this field [
13]. Despite this effort, county-specific records of vehicle collisions with wild game remain sparse, with detailed species records only starting from June 1, 2022 [
13]. These detailed records from 2022 exist because the Croatian Hunting Association took over the payment of compensation for damage to vehicles in the event of a collision with wild game [
13]. In Osijek-Baranja County, from June 1, 2022, to May 31, 2023, there were 302 recorded vehicle collisions with wild game [
13]. The roe deer was the most frequently involved, followed by the wild boar and the red deer, which together amounted to 78.80% of all wild game run over [
13]. However, according to our data, on the Zmajevac-Osijek road during the same period, only 2.32% of the run over animals were large game. Also, on the same road (Zmajevac–Osijek) and during the same period (June 1, 2022 to May 31, 2023), six European badgers and one red fox were run over. The Croatian Hunting Association data for Osijek-Baranja County during this period shows run overs of nine European badgers and nine red foxes [
13]. Thus, the Zmajevac-Osijek road accounted for 66.66% of all European badgers and 11.11% of all red foxes run over in the county, despite the road representing only 1.96% of the total road network. This high proportion of European badgers relative to the small percentage of road sections belonging to the Zmajevac-Osijek road suggests deficiencies in the records maintained by the Croatian Hunting Association. Notably, while roe deer are the most frequently involved large wild game animals in vehicle collisions in Croatia [
11,
29], no collisions with roe deer were recorded on the Zmajevac-Osijek road between 2016 and 2024. Roe deer is the most numerous species of large game in Croatia [
30]. However, in the area of Slavonia and Baranja the roe deer population has been considerably reduced due to the invasion of the large American liver fluke,
Fascioloides magna Bassi, 1875 (Plagiorchiida: Fasciolidae [
30]. Sometimes, discrepancies arise between the data reported by the Ministry of the Interior Republic of Croatia and the Croatian Hunting Association regarding the number of recorded run over animals. For example, the Ministry of the Interior recorded 684 vehicle collisions with animals in 2020 and 717 in 2021 [
14,
15]. On the contrary, the Croatian Hunting Association recorded 4,048 run-over animals on Croatian roads for the same period [
13]. Collisions involving smaller wild animals (European badger, red fox, stone marten, pine marten, European wildcat) typically result in minimal material damage to vehicles, which may lead to these incidents being recorded sporadically. This discrepancy could be a primary reason for the variation in annual run over animal counts reported. Comparing data from the Zmajevac-Osijek road with similar data from other Croatian counties is challenging, as reports usually focus on large game, with other animals mentioned less frequently. Comprehensive data on wild animals run over on the section of State Road D1 from Klinča Sela to Karlovac, offering a basis for comparison, were reported in 2016 [
31]. According to these data, on this 25 km section, the northern white-breasted hedgehog ranked first with 60 run-over specimens (45.80% of the total), while the red fox was third with 13 specimens (9.92%) [
31]. These figures closely align with those recorded in our study on the Zmajevac-Osijek road, where the northern white-breasted hedgehog is also the most frequently run over species (45.24%), and the red fox ranks third (14.28%). Similarly, the northern white-breasted hedgehog is the most frequently run over species on roads in Hungary [
32]. For the European hedgehog,
Erinaceus europaeus L. 1758 (Eulipotyphla: Erinaceidae), which is widespread in northern and western Europe, there is significantly more literature available compared to
E. roumanicus. The European hedgehog inhabits similar environments and exhibits comparable behaviours. It ranks highest for road mortality in Vienna, Austria [
4], second in southern Ireland [
33] and in the Campania region of southern Italy [
34]. In the Netherlands, road traffic is estimated to reduce the density of
E. europaeus by about 30%, affecting local population survival [
35]. Similarly, in southern Sweden, traffic accidents are a major cause of death for
E. europaeus [
36]. This species is among the most frequent road casualties wherever its populations intersect road networks [
37]. Data on run over E
. roumanicus are scarce. In Croatia, information on road mortality for
E. roumanicus is limited, partly because collisions with these small mammals rarely cause significant vehicle damage or pose a threat to drivers. Across Europe, road collisions with large game (wild boar, roe deer, and red deer) are more commonly recorded due to their potential for severe vehicle damage and associated risks to human life [
38]. Although Croatia has a lower incidence of ungulate road collisions compared to other European countries [
39], on the Zmajevac-Osijek road the number of run over wild mammals per km was 0.77 in 2023 and 0.86 in 2024. Despite being the most frequently run over species on this road,
E. roumanicus was not recorded during the species hibernation period in late autumn and winter months (November through March). Similarly, run over of European badgers,
M. meles, were not observed in November, December, and January, because the species also hibernates during this period. The mortality data for European badgers in this study show a unimodal peak in spring, which contrasts with the bimodal peak observed in southern England during spring and late summer [
40]. In this study, European badgers rank second in mortality, consistent with findings from the Po-Veneto plain in Italy [
41], but at odds with earlier studies where the percentage of run over European badgers in Croatia was below 3% [
11,
12,
27,
31]. In Britain, road traffic is the leading cause of European badger deaths, indicating that road traffic significantly affects badger populations through habitat fragmentation at the local level [
42]. The red fox,
V. vulpes, ranks third among run-over species on the Zmajevac-Osijek road in Osijek-Baranja County. It is the most frequently run over small mammal in the Campania region of southern Italy and in northern Poland [
34,
43], and second in south-western Germany [
44]. In our study on the area of Osijek-Baranja County, the majority of run over red foxes were recorded in October, showing a unimodal seasonal mortality pattern. These data are not in agreement with those of UK, where no significant seasonality was observed [
45]. Collisions involving small to medium-sized vertebrates and carnivores are often linked to roadside vegetation [
46], which may explain the high number of run over mammals recorded on the sixth section of the road through the Lug settlement in this study. During the COVID-19 pandemic, run over rates dropped considerably to 3.48%, similar to reduced mortality observed for European badgers and red foxes in the UK in the same period [
47].