Roads are essential for social and economic development, but their presence often leads to deforestation, habitat loss, changes in wildlife behaviour and distribution, and loss through collisions with vehicles. In southern Bahia state in Brazil’s Atlantic Forest hotspot, cocoa agroforestry systems are vital in connecting natural fragments and supporting local biodiversity. This study assessed the impacts of a 24 km segment of the BA-262 road, a route linked to the construction of a new port. During May–December 2022, we recorded vertebrate roadkill events and analysed their relationship with traffic volume, identifying high-risk zones. Camera traps and live traps were deployed in forest fragments to evaluate mammal presence near and along the road, comparing species detected near the road with those recorded as roadkill. In total, we documented 243 roadkill events, with amphibians being the group most affected (153 individuals, 63% of the total recorded), followed by reptiles (49, 20%), birds (28, 12%) and mammals (13, 5%). Hotspot analyses revealed nine roadkill clusters. Camera traps along the road recorded 409 images of 21 mammal species from eight orders. Although species richness was unaffected by proximity to the road, relative abundance increased closer to the road. Mammals appeared less affected by the road than other groups, probably because they are mostly active at night, when traffic is lower. This research highlights the ecological impacts of roads on biodiversity-rich areas, underscoring the need for mitigation measures to reduce wildlife mortality and offering insights for future research.

This study examines mortality of the Amur tiger Panthera tigris altaica caused by traffic collision incidents in the Russian Far East from 1980 to 2023. Forty-six per cent of mortality incidents occurred within the last 4 years of this period (2020–2023) following an outbreak of African swine fever, which led to a reduction of prey available for tigers. Using multiple regression analysis, we identify significant predictors of tiger mortality, including road type, biotope, and distances to settlements and federally protected areas. We identified five locations with concentrations of tiger mortality, with four of these near protected areas comprising 54% of all incidents. Asphalt roads have an elevated risk of tiger deaths during the winter, whereas unpaved roads have elevated risk during warmer months. Wildlife-friendly road planning, including crossings and enhanced night-time controls, is crucial for reducing mortality and ensuring the survival of this species amidst increasing development of human infrastructure. This study highlights the urgent need for targeted conservation efforts to reduce traffic-related risks to the Amur tiger.

In Singapore, the Critically Endangered Sunda pangolin Manis javanica is threatened by habitat loss and fragmentation, and road traffic collisions. To mitigate these threats, an understanding of its spatiotemporal distribution is needed, as identified in the National Conservation Strategy and Action Plan for the species. However, Sunda pangolin occurrence data are held in multiple separate databases, are typically collected using non-standardized methods, and often lack accurate location details. To compile a complete georeferenced database of Sunda pangolin records in Singapore, we consolidated occurrence data from heterogeneous databases and mainstream and social media, and converted locality descriptions into geographical coordinates. We demonstrate the use of this database to analyse data on rescued pangolins and those killed on roads, to aid conservation efforts in Singapore, and describe other potential applications. We georeferenced 482 records of pangolin sightings, rescues and roadkill for 1996–2021, finding an increase in all three over the study period. Roadkill and rescues occurred mostly in central and western Singapore, close to forested areas, and were predominantly of subadults and adult males. The data can be used to inform threat mitigation strategies, post-rescue release plans and further research. The database has already been used in practice, contributing to environmental impact assessments and conservation recommendations. Overall, this georeferenced database demonstrates the value of citizen science and collating wildlife data from multiple sources, and the methods used can be applied to other taxa to aid conservation strategies.

The expansion of transportation and service corridors has numerous, well-documented adverse effects on wildlife. However, little research on this topic has been translated into mitigating the effects of habitat fragmentation caused by road development on primates. The establishment of canopy bridges has proven to be an effective conservation intervention. Of the completed primate canopy bridge projects reported in the literature, to our knowledge, all attempt to mitigate the impacts caused by singular, linear infrastructure routes. Here we provide recommendations for the establishment of a network of natural and artificial canopy bridges over roads throughout Langkawi Island, Malaysia, to reduce rates of roadkill and support the movement of primates and other arboreal animals across the island by identifying suitable sites and appropriate tree species to be planted (including Ficus racemosa and Ficus fistulosa), bridge materials and post-installation monitoring. The establishment of this pioneering trans-island canopy bridge network could function as a model to enhance connectivity for arboreal animals in other important wildlife habitat sites in Malaysia and beyond that are affected by fragmentation from linear infrastructure. We have begun discussions with relevant authorities, partners and other pertinent parties, focusing on the initiation of construction of the canopy bridge network in 2024.

Roads affect wildlife in a variety of negative ways. Road ecology studies have mostly concentrated on areas in the northern hemisphere despite the potentially greater impact of roads on biodiversity in tropical habitats. Here, we examine 4 years (January 2016–December 2019) of opportunistic observations of mammalian roadkill along a road intersecting Jozani-Chwaka Bay National Park, Unguja, Zanzibar. In particular, we assess the impact of collisions on the population of an endemic primate, the Endangered Zanzibar red colobus Piliocolobus kirkii. Primates accounted for the majority of roadkill in this dataset. Monthly rainfall was not associated with roadkill frequency for mammals generally, nor for the Zanzibar red colobus. No single age–sex class of colobus was found dead more often than expected given their occurrence in the local population. The overall effect of roadkill on colobus populations in habitats fragmented by roads is unknown given the lack of accurate, long-term life history data for this species. Our findings suggest that mortality from collisions with vehicles in some groups of colobus is within the range of mortality rates other primates experience under natural predation. Unlike natural predators, however, vehicles do not kill selectively, so their impact on populations may differ. Although a comparison with historical accounts suggests that the installation of speedbumps along the road near the Park's entrance has led to a significant decrease in colobus roadkill, further actions to mitigate the impact of the road could bring substantial conservation benefits.