The European mink (Mustela lutreola) is one of the most endangered mammals in Europe, with an estimated population of only 142 individuals in Spain (range 130-157). Roadkill has been identified as main cause of non-natural mortality (around 90% mortality between 1980-2008), jeopardizing their survival. In a previous project, LIFE LUTREOLA (2014-2019), a total of 44 European mink roadkill in road intersections with river corridors were registered. The current project, carried out in Araba (Basque Country), inventoried a total of 30 transversal structures on road sections experiencing European mink roadkill. Field works were undertaken to characterize these structures and actions in each structure and its surroundings were designed to enhance use of the structure as adapted culverts by European mink and other wildlife. Building Information Modelling (BIM) was used to design the adaptations undertaken in each structure and will permits the integration of wildlife monitoring results, both within structures and their surroundings. Measures to be implemented where drainage is proposed for adaptation consist of i) installation of dry ledges at both sides of passages, ii) removal of obstacles at entrances, and iii) restoration of riparian vegetation to guide animals inside the passage. Recommendations for drains with lower hydraulic capacities include their replacement or enlargement to restore ecological connectivity and to increase road resilience against floods. This approach helps find synergic solutions which tackle several challenges simultaneously, since the consideration of climate-related risks while designing mitigation measures is key in the current climate change context.

Causes of Eurasian otter mortality in the Czech Republic are systematically studied since 2008. As the population increases, we get up to 80 records of dead otters per year, from which 80 % are traffic collision. Both, males and females of all age classes die on roads. Due to continuous increase in traffic intensity and construction of new infrastructure, the calculated otter population viability model in the Czech Republic showed that there is a point when the increasing mortality of otters will exceed the population natality and the whole population will start to decrease. Three main types of collision places were identified: simple crossing of running water body and road (44 % of victims), dams with roads (28 %) and places without water presence (27 %). Evaluation of selected sample of 1st class roads (540 km, totally 264 water crossings) revealed that about 20 % of places are potentially dangerous for passing otters. There are regional differences caused mainly by character of water network. We bring several examples of simple and more sophisticated collision site improvements carried out in last decades in the Czech Republic. Subsequent monitoring shows that all built measures enabled safe passage for otter and not only for otters. As streams and their banks act as natural corridors for many semi-aquatic and terrestrial mammals that may also use those passages.

The otter (Lutra lutra) is a protected species in the EU. This semi-aquatic predator usually finds its habitat within 10 meters of the water's edge but is often killed along roads. However, otters could cross roads under bridges and like to stay in their prime habitat, the water. The generally used hypothesis for this behavior is that otters get killed because of structural deficiencies under bridges and in pipes. Within the last 20 years, 350 otter road mortalities were documented and analyzed in Eastern Austria concerning distance to the nearest bridge and watercourse, structural deficiencies of the bridge/pipe, migratory obstacles in the river, fishponds, and likely cross-country trails. It turns out that only a small proportion of otters are killed on roads close to bridges and pipes, and when this is the case, there are often no structural deficiencies at the site in question that could be improved. Frequently, otters traverse roads where the river or stream does not cross the road, often surprisingly far from the water. Therefore, the places where otters die on the road are difficult to predict, making it difficult to take preventive measures. Implications of these findings are discussed.

In human-wildlife interfaces like roads passing through forests, wild animals, particularly prey, may perceive humans and traffic as ‘super-predators’, which can reduce mortality risk but increase the barrier effect. Prey may also associate humans with reduced presence of their natural predators, that can increase their vulnerability to roadkill. Herds of chital, a common group-living cervid, are commonly found foraging along the NH 44 that passes through the Pench Tiger Reserve in central India. We compared chital anti-predation strategies viz., vigilance behaviour and group size, between the roadside habitat and control habitat inside the park to test whether chital perceive roadsides as dangerous but resource-rich habitats, or as predator-free zones with non-lethal predictable human behaviour. We found that chital at the roadsides were proportionally more vigilant, with shorter feeding bouts, and more frequent feeding and vigilance events as compared to control. While group size and group vigilance did not vary significantly between the two sites, the average duration of a vigilance bout at the roadside was higher than that inside the reserve. Absence of activities like resting, nursing, vocalising and auto-grooming indicates that chital near the highway forgo these activities to allocate more time to vigilance. Our findings indicate that chital adjust their anti-predation strategies to maximally use roadside habitats in the reduced presence of natural predators and competitors, but with social and fitness costs. The study has implications for managing chital roadkill on highways, and for understanding possible long-term impacts on chital sociality and trophic cascades.

Roads are essential for a country’s economic development, especially for developing countries like India. With the world’s second largest road network, India is currently experiencing a phase of rapid road network expansion. Consequently, roads have emerged as one of the most potent threats to wildlife, particularly threatening large connected landscapes that are a pre-requisite for the conservation of wide-ranging flagship species like the tiger. Consequently, large-scale assessment of roads in critical habitats is important to gauge the extent of the impacts roads may pose for conservation of such species. We characterised the road network in the Indian tiger range through different metrics. We found that 58,000 km of different road types intersect tiger habitats in India. About half of these roads pass through priority (Tx2) Tiger Conservation Landscapes (TCLs), and 22.5% pass through tiger reserves (TRs). Protected areas in TCLs had comparatively lower tarred road densities, while buffer zones of TRs had 1.7 times higher tarred road densities than core zones. We found that 63% of the entire Indian tiger range is within 5 km of the nearest tarred road. Our results demonstrate the characteristics and potential drivers of the road network in Indian tiger landscapes. Even though certain frameworks to ensure regulation in road development in Indian tiger landscapes have emerged in the recent past, future road development plans in such regions, especially non protected areas, should be aimed at maintaining the connectivity of these landscapes that hold the last remaining wild tiger population in the world.

Two strategic documents issued by the Chinese Central Government projected that, by the mid-21st century, the linear transport infrastructure (LTI) network of China will rank at the forefront of ecological and sustainable transport networks globally. With this goal, it is urgent to summarize existing research, benchmark international research levels, and propose development directions and strategies for terrestrial vertebrate species protection around LTI in China. In this study, we searched for peer-reviewed papers before 2020 in both Chinese and international databases. A total of 170 academic articles were collected. Most focused on roads, but some focused on railways, of which the Qinghai-Tibet Railway occupied half. The most researched taxa were mammals, including the Tibetan antelope (Pantholops hodgsonii), Siberian tiger (Panthera tigris), and Asian elephant (Elephas maximus), the number of bird research papers was less than half that of mammal research papers, and fewer amphibian and reptile studies. The impact of LTI on wildlife was classified to habitat effects, roadkill, behavioral influences, and barrier effects. Wildlife preservation efforts included wildlife and habitat surveys, route selection, subgrade and pavement design, and the design and monitoring of wildlife crossing structures. Studies were concentrated in five zoogeographical regions, i.e., the Qinghai-Tibet, South China, Central China, Northeast China, and Southwest China regions. Conservation suggestions, knowledge gaps, and future research directions for China were identified through comparisons with the state of international research. These focal priorities will help guide the development of road ecology in China.

The construction of the Qinghai-Tibet railway parallel to the Qinghai-Tibet highway has raised concerns about the impact of transportation facilities on local wildlife. However, most of this research occurred after the railway was built, leading to a lack of data on how the construction affected wildlife. By comparing data from surveys of ungulates along the Qinghai-Tibet Highway in 2001-2002 and 2014-2020, we observed changes in the number, herd size, and distribution of ungulates before and after the railway construction. Our study revealed an increase in the number of ungulates and a decrease in herd size after the railway's completion, along with shifts in their distribution along the highway. Notably, ungulate numbers decreased in areas where the road and railway were close but increased where they were further apart. We found that effective protection measures can mitigate the impact of traffic facilities on ungulate populations, allowing them to adapt. However, close proximity of the two transportation routes can have a cumulative negative effect on ungulate numbers. These findings suggest the potential for achieving harmonious coexistence between transportation infrastructure and wildlife on the Tibetan Plateau in the future.

Since its return to The Netherlands in 2017 and until October 2023, 17 grey wolves (Canis lupus) have been killed in collisions on Dutch roads. Animal-vehicle collisions can have a major impact on traffic safety and mortality can have major consequences for the viability of populations of large mammals such as the wolf. This research was conducted to determine the magnitude of these impacts and possible measures that could be undertaken to prevent wolf-vehicle collisions in addition to the measures taken within the framework of the multi-annual defragmentation programme (MJPO).
Literature research was performed to answer the questions and interviews were conducted. National data from Dutch road kills were compared to data from road kills in Germany. The main findings are that current fauna measures in a coherent network of green bridges, seem to be sufficient in a large core area on the Veluwe. The existing fauna measures in a largely fragmented landscape “De Kempen” near the border with Belgium seem to be less effective because relatively many wolves have been killed in collisions on the A2 highway. Most wolves involved in collisions in The Netherlands were young individuals, which corresponds with German data. A Maxent model was constructed to identify possible future ‘hotspot’ areas based on environmental characteristics. Currently, the model is non-significant in a leave-one-out cross validation with an exact binomial test, likely due to an insufficient amount of datapoints, but the methodology of this research might be useful in the future, when more collisions are expected.