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Roads are one of the most widespread structures that drive habitat loss and fragmentation. But they also restrict animal movement and drive landscape-level impacts on biodiversity. The South Pacific of Costa Rica is known for its high levels of biodiversity, but little has been done to reduce road impacts upon wildlife communities. To understand these impacts and advise on possible mitigation action, we used three key data approaches: 1. Camera traps, to survey wildlife activity along two major road sections that dissect the region's protected areas and biological corridors. Seventy-eight camera traps were deployed in secondary forest patches at different distances (between 200 m and 1 km) from the roads for six months and covariates were collected to explain the patterns found. 2. Citizen science data extracted from iNaturalist to identify roadkill "hotspots" along the roads. And 3. Circuitscape analysis, to assess how landscape structure could influence animal movement. Camera traps recorded 30 terrestrial species. Ocelots and agoutis displayed a negative effect of distance from protected area, while the Apex predators displayed a positive effect toward higher forest cover and vegetation density. Circuitscape analysis showed high connectivity throughout most of the area. Only a few locations showed higher flow (bottle neck locations), which coincided with roadkill "hotspots" identified through citizen science direct observations (70 observations of 21 species). Amalgamating data from the different analyses allow us to identify four key wildlife crossing locations (one of less priority) along the Inter-American Highway. We strongly recommend the placement of under/overpasses in these locations, with the aim to ensure wildlife safe movement and connectivity of wildlife populations in the region. Culvert modifications in the area could also be considered to incorporate wildlife underpasses at a reduced cost. • Roads restrict animal movement and drive landscape-level impacts on biodiversity. • Road impact on the high biodiverse forest of Southern Costa Rica is understudied. • To inform mitigation actions three methodologies were used and results overlapped. • Four key locations were identified to implement wildlife safe crossing structures. [ABSTRACT FROM AUTHOR]

Abstract Road mortality is the most easily visible effect of roads and traffic on wildlife populations. Mitigation measures such as fences and wildlife passages have been applied to reduce these effects. During the widening of Quebec's Highway 175 from two to four lanes between 2006 and 2012, 33 wildlife passages designed specifically for small and medium-sized mammals were installed under the road in combination with short fences. This study examined the effectiveness of the fences at reducing the number of small and medium-sized mammals killed along a 68 km section of the road while controlling for the potential confounding effects of landscape variables. Repeated daily mortality surveys were conducted by car during the summers of 2012–2015 to measure roadkill occurrence and detection probability. A total of 893 dead animals from 13 taxa were detected. Roadkill occurrence was significantly greater at fence ends than in fenced sections and unfenced sections (fence-end effect), indicating that the fences were not long enough to discourage animals from moving along the fence to the fence ends. Greater length would be required to meet the target of reduced road mortality. Shrubby vegetation in the median strip separating the two directions of the highway was associated with high roadkill occurrence for medium-sized species. Roadkill detection probability for all species combined was 0.72, ranging from 0.17 for small mammals (<1 kg) to 0.82 for medium-sized mammals (>1 kg). To reduce road mortality, when wildlife passages are constructed along with new highways or retrofitted to old highways, fences either should be continuous or sufficiently long to encourage passage use rather than movement around the fence ends. Future road mortality studies should be combined with data about wildlife abundance and detection probability to more accurately estimate the effects at the population level. Graphical abstract Image Highlights • The study addresses the effectiveness of mitigation measures at reducing roadkill. • Detection probability ranged from 0.17 (small) to 0.82 (medium-sized mammals). • Landscape variables (distance to forest, etc.) influenced spatial roadkill patterns. • Roadkill levels were higher at fence ends than within fenced and unfenced sections. • The fences were not long enough to meet the target of road mortality reduction. [ABSTRACT FROM AUTHOR]

Abstract Along many roads worldwide, drainage culverts are the only structures wildlife can safely use to cross. However, culverts inundate and can become unavailable to terrestrial fauna during rainy periods. We conducted a field study over wet and dry seasons in southern Portugal to assess the effect of culvert flooding on crossings by medium-sized carnivores. We set up track stations inside 30 culverts along intermediate-level traffic roads to evaluate complete crossings (n = 1211) and used mixed-effects models to quantify the effects. Carnivores were more likely to cross and crossed more frequently if the culvert had a natural dry pathway at the time of the crossing. Carnivores were also more likely to cross culverts with streams running through them. Moreover, culverts with flowing streams during the wet season were still more likely to be crossed during the dry season when the streams were dry. The significance of the difference in crossing rates between wet and dry seasons was species-specific. Our study reveals that flowing water and dry pathways jointly contribute to promoting crossings by this carnivore community. Culverts including streams may act as a continuation of riparian corridors, being incorporated into carnivores' movement routes. Our results lend empirical support to recommendations advising the implementation of dry pathways to provide crossing paths. Interventions to offset the transient impacts of water flooding in new or existing culverts can be a cost-effective solution promoting connectivity across roads allowing movement of individuals. Highlights • We analyzed how flooding may hamper carnivore crossings through drainage culverts. • Flowing water and dry pathway jointly contribute to promoting crossings. • Mitigations in culverts with flowing water to provide a dry path can be a cost-effective solution when funds are limited. • Such mitigations promote connectivity across roads allowing movement of individuals. [ABSTRACT FROM AUTHOR]

Abstract In 2003–2005, we resurveyed and expanded plots surveyed in 1985 to examine the cumulative impact of road salt (sodium chloride) and sand along a two-lane highway in the Adirondack State Park in New York State (USA). Annual salt applications in the period 1985–2005 ranged from 50 tonnes per centerline-km (1985) to 140 tonnes (2005) and sand applications ranged from nearly zero tonnes (2005) to 325 tonnes (1985). Roadside soils and vegetation were significantly impacted by salt deposition compared to soils and vegetation 30 m and 150 m from the road. Roadside soil contained more sand, less organic matter, had a lower cation exchange capacity, was denser, and retained less water than soils 30 m and 150 m from the road. The concentration of sodium in roadside soils was elevated (103 vs. 44 ppm in soil 150 m from the roadside), and roadside concentrations of plant-nutritive cations were lower than 150 m from the road (roadside Mg, Ca and K concentrations were 0.2, 5, and 1 ppm respectively vs. 23,168, and 30 ppm at 150 m from the road). Along the roadside, paper birch trees ( Betula papyrifera ) and other woody vegetation present in 1980 were absent in 2004, suggesting that survival and recruitment of paper birch trees was impacted by degradation of soil fertility, deposition of road salt and aerosolization of salt from the roadway. Roadside environmental degradation caused by winter road management has worsened since 1980; revegetation with native salt-tolerant plants may provide some mitigation of the most severe effects. Overall, we conclude that the full extent of roadside environmental degradation caused by winter road management can take decades to manifest, and this may be the case more generally along cold-climate montane roadways. Highlights • Heavy winter applications of road salt and sand adversely impacted roadside soils and vegetation along a mountain pass. • Roadside soils had altered physical and chemical properties that lowered fertility due to road salt and sand use in winter. • Soils lost plant-nutritive cations (Mg, Ca, K) which were replaced by Na from road salt. • Tree mortality and vegetation loss was caused by direct harmful effects of salt on plants and decline in soil fertility. • Recommended remediation included revegetation with native salt-tolerant, cold-tolerant plants. [ABSTRACT FROM AUTHOR]

Human activities, from resource extraction to recreation, are increasing global connectivity, especially to less-disturbed and previously inaccessible places. Such activities necessitate road networks and vehicles. Vehicles can transport reproductive plant propagules long distances, thereby increasing the risk of invasive plant species transport and dispersal. Subsequent invasions by less desirable species have significant implications for the future of threatened species and habitats. The goal of this study was to understand vehicle seed accrual by different vehicle types and under different driving conditions, and to evaluate different mitigation strategies. Using studies and experiments at four sites in the western USA we addressed three questions: How many seeds and species accumulate and are transported on vehicles? Does this differ with vehicle type, driving surface, surface conditions, and season? What is our ability to mitigate seed dispersal risk by cleaning vehicles? Our results demonstrated that vehicles accrue plant propagules, and driving surface, surface conditions, and season affect the rate of accrual: on- and off-trail summer seed accrual on all-terrain vehicles was 13 and 3508 seeds km −1 , respectively, and was higher in the fall than in the summer. Early season seed accrual on 4-wheel drive vehicles averaged 7 and 36 seeds km −1 on paved and unpaved roads respectively, under dry conditions. Furthermore, seed accrual on unpaved roads differed by vehicle type, with tracked vehicles accruing more than small and large 4-wheel drives; and small 4-wheel drives more than large. Rates were dramatically increased under wet surface conditions. Vehicles indiscriminately accrue a wide diversity of seeds (different life histories, forms and seed lengths); total richness, richness of annuals, biennials, forbs and shrubs, and seed length didn't differ among vehicle types, or additional seed bank samples. Our evaluation of portable vehicle wash units showed that approximately 80% of soil and seed was removed from dirty vehicles. This suggests that interception programs to reduce vehicular seed transportation risk are feasible and should be developed for areas of high conservation value, or where the spread of invasive species is of special concern. [ABSTRACT FROM AUTHOR]

The extent of roads and other forms of linear infrastructure is burgeoning worldwide, but their impacts are inadequately understood and thus poorly mitigated. Previous studies have identified many potential impacts, including alterations to the hydrological functions and soil processes upon which ecosystems depend. However, these impacts have seldom been quantified at a regional level, particularly in arid and semi-arid systems where the gap in knowledge is the greatest, and impacts potentially the most severe. To explore the effects of extensive track, road, and rail networks on surface hydrology at a regional level we assessed over 1000 km of linear infrastructure, including approx. 300 locations where ephemeral streams crossed linear infrastructure, in the largely intact landscapes of Australia's Great Western Woodlands. We found a high level of association between linear infrastructure and altered surface hydrology, with erosion and pooling 5 and 6 times as likely to occur on-road than off-road on average (1.06 erosional and 0.69 pooling features km −1 on vehicle tracks, compared with 0.22 and 0.12 km −1 , off-road, respectively). Erosion severity was greater in the presence of tracks, and 98% of crossings of ephemeral streamlines showed some evidence of impact on water movement (flow impedance (62%); diversion of flows (73%); flow concentration (76%); and/or channel initiation (31%)). Infrastructure type, pastoral land use, culvert presence, soil clay content and erodibility, mean annual rainfall, rainfall erosivity, topography and bare soil cover influenced the frequency and severity of these impacts. We conclude that linear infrastructure frequently affects ephemeral stream flows and intercepts natural overland and near-surface flows, artificially changing site-scale moisture regimes, with some parts of the landscape becoming abnormally wet and other parts becoming water-starved. In addition, linear infrastructure frequently triggers or exacerbates erosion, leading to soil loss and degradation. Where linear infrastructure densities are high, their impacts on ecological processes are likely to be considerable. Linear infrastructure is widespread across much of this relatively intact region, but there remain areas with very low infrastructure densities that need to be protected from further impacts. There is substantial scope for mitigating the impacts of existing and planned infrastructure developments. [ABSTRACT FROM AUTHOR]

We test a forecasting strategy to identify potential hotspots of amphibian roadkill, combining the spatial distribution of amphibians, their relative risk of collision with vehicles and data on road density in Spain. We extracted a large dataset from studies reporting road casualties of 39 European amphibian species and then estimated the 'relative roadkill risk' of species as the frequency of occurrence of casualties for each amphibian and standardized by the range of distribution of the species in Europe. Using a map with the spatial distribution of Spanish amphibians at a spatial resolution of 10 × 10 Km squares, we estimated the 'cumulative relative risk of roadkill' for each amphibian assemblage as the sum of risk estimates previously calculated for each species. We also calculated the total length of roads in each square (road density). Finally, combining all layers of information, we elaborated a forecasting map highlighting the potential amphibian roadkill risk across Spain. Our findings are relevant to suggest areas that should be focused on at more detailed spatial scales. Additionally, we found that the frequency of roadkill was unrelated to the evolutionary distinctiveness score and conservation status of amphibian species, while was positively correlated with their distribution range. [Display omitted] • We estimated the relative risk of roadkill of amphibian species based on a literature review. • We calculated a cumulative risk of roadkill considering the species assemblages. • The cumulative risk of roadkill and road density across Spain were combined. • A forecasting map of amphibian roadkill risk in Spain with potential hotspots was elaborated. [ABSTRACT FROM AUTHOR]

The rapidly growing global road networks put serious pressures on terrestrial ecosystems and increase the number and severity of human-wildlife conflicts, which in most cases manifest in animal-vehicle collisions (AVCs). AVCs pose serious problems both for biodiversity conservation and traffic safety: each year, millions of vertebrates are roadkilled globally and the related economic damage is also substantial. For a comprehensive understanding of factors influencing AVC it is essential to explore the human factor, that is, the habits and attitude of drivers; however, to date, comprehensive surveys are lacking on this topic. Here we addressed this knowledge gap and surveyed the habits of drivers and their experience and attitude towards AVCs by a comprehensive questionnaire covering a large geographical area and involving a large number of respondents (1942 completed questionnaires). We aimed to reveal how driving habits affect the chance of AVC, and explored the attitude of the drivers regarding AVC. We found that the number of lifetime AVC cases was higher for male drivers, for those who drove longer distances per year, had more driven years, used country roads or drove large vehicles. Our results showed that almost half of the drivers surveyed had experienced at least one AVC in their lifetime. Drivers' attitudes towards the importance of nature conservation or traffic safety in the aspect of AVC, and fear of collision showed a significant correlation with experienced AVC cases. Drivers' opinions indicated that the most trusted and desired AVC prevention measures were physical objects such as fences and wildlife crossings. Our research provides guidelines for developing targeted initiatives in the future to increase awareness about the significance of AVC and target those drivers who are most vulnerable to AVC. [Display omitted] • Animal-vehicle collisions (AVC) can potentially affect every second driver. • One out of every four drivers may experience property damage as a result of AVC. • The detectability of AVC depends on the characteristics and size of the animals. • The occurrence of AVC is significantly influenced by the attributes and attitudes of drivers. • Drivers consider physical AVC prevention measures to be the most effective. [ABSTRACT FROM AUTHOR]

Vegetation removal and soil disturbance from natural resource development, combined with invasive plant propagule pressure, can increase vulnerability to plant invasions. Unconventional oil and gas development produces surface disturbance by way of well pad, road, and pipeline construction, and increased traffic. Little is known about the resulting impacts on plant community assembly, including the spread of invasive plants. Our work was conducted in Pennsylvania forests that overlay the Marcellus and Utica shale formations to determine if invasive plants have spread to edge habitat created by unconventional gas development and to investigate factors associated with their presence. A piecewise structural equation model was used to determine the direct and indirect factors associated with invasive plant establishment on well pads. The model included the following measured or calculated variables: current propagule pressure on local access roads, the spatial extent of the pre-development road network (potential source of invasive propagules), the number of wells per pad (indicator of traffic density), and pad age. Sixty-one percent of the 127 well pads surveyed had at least one invasive plant species present. Invasive plant presence on well pads was positively correlated with local propagule pressure on access roads and indirectly with road density pre-development, the number of wells, and age of the well pad. The vast reserves of unconventional oil and gas are in the early stages of development in the US. Continued development of this underground resource must be paired with careful monitoring and management of surface ecological impacts, including the spread of invasive plants. Prioritizing invasive plant monitoring in unconventional oil and gas development areas with existing roads and multi-well pads could improve early detection and control of invasive plants. [ABSTRACT FROM AUTHOR]

Wildlife-train collisions can have deleterious effects on local wildlife populations and come with high socio-economic costs, such as damages, delays, and psychological distress. In this study, we explored two major components of wildlife-train collisions: the response of wildlife to oncoming trains and the detection of wildlife by drivers. Using dashboard cameras, we explored the flight response of roe deer (Capreolus capreolus) and moose (Alces alces) to oncoming trains and explored which factors, such as lighting and physical obstructions, affect their detection by drivers. In a majority of cases, roe deer and moose fled from an oncoming train, at an average flight initiation distance (FID) of 78 m and 79 m respectively. Warning horns had unexpected influences on flight behaviour. While roe deer initiated flight, on average, 44 m further away from the train when warned, they usually fled towards the tracks, in the direction of danger. FID of moose, however, was unaffected by the use of a warning horn. As train speed increased, moose had a lower FID, but roe deer FID did not change. Finally, detection of wildlife was obstructed by the presence of vegetation and uneven terrain in the rail-side verge, which could increase the risk of collisions. Our results indicate the need for early detection and warning of wildlife to reduce the risk of collisions. We propose that detection systems should include thermal cameras to allow detection behind vegetation and in the dark, and warning systems should use cues early to warn of oncoming trains and allow wildlife to escape the railway corridor safely. • Dashboard cameras can be used to evaluate ungulate reactions to oncoming trains. • Roe deer and moose tend to flee from trains, but often onto or across the tracks. • Detection of wildlife was obstructed by rail-side vegetation and terrain. • To reduce risk of collisions, we suggest the use of thermal cameras and early acoustic warning. [ABSTRACT FROM AUTHOR]

Roadkills are amongst the most significant biodiversity impacts, although little is known about the factors which influence the roadkill of neotropical birds. Hence, the objective was to evaluate differences in roadkill richness and rates for neotropical birds according to the seasons of the year and habitat types associated with roads. The data was collected along two federal highways, in southern Brazil. We identified 57 roadkilled species, for a mean roadkill rate of 0.06ind./km/day (Min.=0.009; Max.=0.47). Our results demonstrate that richness and roadkill rates change according to seasonality and habitat types. Roadkills were concentrated in rice fields and wetlands, intensifying both in richness and rates during the summer and autumn. Nearby areas have similar roadkill rates, independent of habitat types. This probably occurs due to the movement of several species seeking food and shelter. Juvenile dispersion, harvest and grain transportation periods, as well as flight and foraging behaviors over road lanes seem to be related to the increasing roadkill occurrences and richness regarding more abundant species. However, given the elevated number of occasionally roadkilled species (more than 70% with N <5), we believe that highway surface and traffic act as physical barriers which inhibit the movement of many species which either present occasional roadkills or none at all. [Copyright &y& Elsevier]

Abstract: Roads have large impacts on wildlife, as they form one of the principal causes of mortality, and disturbance and fragmentation of habitat. These impacts are mainly studied and mitigated on major roads. It is, however, a widespread misconception that most animals are killed on major roads. In this paper, we argue that minor roads have a larger impact on wildlife with respect to habitat destruction, noise load and traffic mortality. We use data on traffic related deaths in badgers (Meles meles) in The Netherlands to illustrate that traffic mortality is higher on minor roads. We ask for a more extensive investigation of the environmental impacts of minor roads. Moreover, we argue that the success of mitigation on roads drastically increases when both major and minor roads are integrated in the planning of traffic flows. Therefore, we propose a strategy based on the concept of a “traffic-calmed area”. Traffic-calmed areas create opportunities for wildlife by decreasing limitations for animal movement. We ask for further studies to estimate what size traffic-calmed areas should be to maintain minimum viable animal populations. [Copyright &y& Elsevier]

Abstract: Numerous road and railway construction projects include costly mitigation measures to offset the barrier effect produced on local fauna, despite the scarcity of data on the effectiveness of such mitigation measures. In this study, we evaluate the utility of different types of crossing structures. Vertebrate use of 43 transverse crossing structures along the A-52 motorway (north-western Spain) was studied during spring 2001. Research centered on wildlife passages (9), wildlife-adapted box culverts (7), functional passages (6 overpasses, 7 underpasses) and culverts (14), with marble dust being used to record animal tracks. A total of 424 track-days were recorded, with most of the larger vertebrate groups present in the area being detected. All crossing structure types were used by animals, although the intensity of use varied significantly among them (Kruskal–Wallis test, p<0.05); culverts were used less frequently than other structures. Crossing structure type and width were identified as the most important factors in their selection for use. Wildlife passages and adapted culverts allowed crossing by certain species (wild boar, roe deer, Eurasian badger), which do not tend to cross elsewhere. These results highlight the importance of using both mixed-type structures and wildlife passages in reducing the barrier effect of roads. [Copyright &y& Elsevier]

Vehicle collisions with wildlife have the potential to negatively impact species everywhere roads divide natural habitats; this is especially true in areas where roads are a recent addition to the landscape (e.g., in the last decade) and/or where expansion of a road network is underway. This study addresses the impact of traffic fatalities on lava lizards, Microlophus albemarlensis, on the island of Santa Cruz, Galápagos. The main road bisecting the island north to south was added to the island beginning in 1974 but not fully paved until 2000. We assessed impacts occurring due to traffic and vehicle speeds on the island. This study adds impacts to lizard populations to those conducted on birds on Santa Cruz, providing a means to create multi-species recommendations. To quantify impacts to lizard populations, we assessed lizards on randomly chosen transects perpendicular to the road. We used Poisson regression to analyze those data and found a 30% increase in lizard abundance per 100m distance from the road across vegetation zones. We compared incidence of prior tail loss of road-killed lizards and live animals to comment on additional energetic costs of occupying near-road territories. Tail condition could not be assessed in some roadkilled lizards; among those that we could assess, 29% showed evidence of prior tail loss. That rate declined to apparent baseline conditions of only 1% beyond 200m from the road. By traveling the length of the 40-km road, we identified hot spots for fatalities of both lizards and birds to provide necessary information for developing management and remediation strategies. We offer guidance on Best Management Practices, such as testing overpasses, fencing and underpasses, which might reduce vehicle impacts to lizards from drivers on the current road. This information is essential because of a planned increase in the Santa Cruz road network in areas where lava lizards are most abundant. [Copyright &y& Elsevier]

Vehicles collide with hundreds of thousands of deer on European roads each year. This leads to animal deaths and suffering, economic damage and risks for human safety, making the reduction of road mortality a major field in conservation biology. In order to successfully reduce roadkill, we need improved knowledge regarding spatio-temporal patterns of deer-vehicle collisions (DVCs) on a landscape scale. Here, we analyzed >85,000 DVCs collected over 17 years in Denmark to investigate changes in the number of DVCs over time and to find spatio-temporal patterns of DVC occurrence. We used a use-availability design – originally developed for habitat selection analyses – to compare DVCs involving roe deer (Capreolus capreolus), red deer (Cervus elaphus) and fallow deer (Dama dama) with random road locations on a landscape scale. This approach enabled us to combine temporal (seasonal and diel variation), spatial (land cover, road density and type) and other relevant variables (deer population density, traffic, and deer activity) within the same analysis. We found that factors related to infrastructure and land cover were most important in explaining patterns of DVCs, but seasonal and diel changes, deer activity, and population density were also important in predicting the occurrence of DVCs. Importantly, patterns of DVCs were largely similar between the three deer species, with more DVCs occurring at intermediate traffic density, increasing forest cover, during dusk and dawn, and with increasing deer activity and population density. The strong and consistent patterns found here will allow the development of flexible mitigation measures. We propose that our findings could be used to develop a spatio-temporally flexible warning system for smartphones and navigation systems that is based on existing map providers, making it a widely available and cheap mitigation measure. [Display omitted] • Knowledge about spatio-temporal patterns of deer-vehicle collisions will help to mitigate roadkill. • Factors related to infrastructure and land cover explained roadkill patterns. • Temporal variation, deer activity, and population density were also important predictors. • Our findings will enable the development of spatio-temporally flexible warning systems. [ABSTRACT FROM AUTHOR]

Wildlife crossing structures can provide safe passage for wildlife across transportation corridors, and can help mitigate the effects of highways and exclusion fencing on wildlife. Due to their costs, wildlife crossing structures are usually installed sparsely and at strategic locations along transportation networks. Alternatively, non-wildlife underpasses (i.e. conventional underpasses for human and domestic animal use) are usually abundant along major infrastructure corridors and could potentially provide safe crossing opportunities for wildlife. To investigate this, we monitored the use of 40 non-wildlife underpasses by roe deer (Capreolus capreolus), and moose (Alces alces) in south-central Sweden. We found that roe deer and moose use non-wildlife underpasses, and prefer underpasses that are at least 11.5 m wide and 5 m tall. Furthermore, roe deer used structures that had little human co-use and were in locations where the forest cover differed on both sides of the highway. In most cases, roe deer and moose were detected within 50 m of the underpass more than they were detected crossing under them. This suggests that animals often approach underpasses without crossing under them, however modifications to underpass design may improve non-wildlife underpass use. We recommend non-wildlife underpasses at gravel and minor roads, particularly those with little human co-use and with variable forest cover on both sides of the highway, be built wider than 11.5 m and taller than 5 m. • Non-wildlife underpasses are actively used by roe deer and moose. • Roe deer and moose tend to use underpasses with little human use and variable forest cover on both sides of the road. • Underpasses that are at least 11.5 m wide and 5 m tall are likely used by roe deer and moose. • Non-wildlife underpasses may supplement connectivity provided by wildlife crossing-structures. [ABSTRACT FROM AUTHOR]

Roads increase wildlife mortality and present a movement barrier for many species. While wildlife passages have been advocated as a solution to many of the problems associated with roads, they are expensive and many roads still have none. However, roads usually have a series of drainage culverts designed to allow water to cross underneath the road, which might also be used by some mammals. This study aims to (1) determine what variables influence the number of successful passages of drainage culverts by mammals, and to (2) parse the effects that these variables have on the entry into and subsequent full passage of drainage culverts by individual mammals, using cameras and animal track stations along a 20 km stretch of autoroute 10 in Southern Quebec (Canada). Overall, 20 species were observed outside of the drainage culverts, but only about half of them were detected making full crossings. While various species were often seen outside, only animals highly tolerant to water, including raccoons (Procyon lotor) and American mink (Neovison vison), were observed fully crossing the structures with regularity, whereas the number of full crossings was small (<8) for all other species. High-water levels and use of polyethylene as a construction material were the strongest deterrents for both the number of successful passages and the probability of entry into the culverts. While several variables (e.g., water level, structure material, moon luminosity, distance to forest) influenced culvert entry, none had an influence on a mammal's probability of complete passage once it had entered. The results imply that ordinary drainage culverts are unsuitable as substitutes for designated wildlife passages for mammals. We recommend the installation of designated wildlife passages and fences, and that in places where wildlife passages are not feasible, dry ledges be installed in existing drainage culverts to better allow small and medium-sized mammals to safely cross under roads while avoiding the water inside of the culverts. To our knowledge, this study is the first to successfully combine trail cameras inside of drainage culverts with track-box data in the adjacent habitat. Image 1 • We asked what species use ordinary drainage culverts under roads to cross safely. (80). • Twenty species were observed outside the drainage culverts, but only few used them. (82). • Only two species highly tolerant to water crossed the structures regularly. (74). • Water level and polyethylene as construction material were the strongest deterrents. (85). • Drainage culverts are unsuitable as substitutes for wildlife passages for mammals. (81). [ABSTRACT FROM AUTHOR]

In an attempt to improve cost-effectiveness, it has become increasingly popular to adapt wildlife crossing structures to enable people to also use them for safe passage across roads. However, the required needs of humans and wildlife may conflict, resulting in a structure that does not actually provide the perceived improvement in cost-effectiveness, but instead a reduction in conservation benefits. For example, lighting within crossing structures for human safety at night may reduce use of the structure by nocturnal wildlife, thus contributing to barrier and mortality effects of roads rather than mitigating them. In this study, we experimentally evaluated the impact of artificial light at night on the rate of use of wildlife crossing structures, specifically underpasses, by ten insectivorous bat species groups in south-eastern Australia. We monitored bat activity before, during and after artificially lighting the underpasses. We found that bats tended to avoided lit underpasses, and only one species consistently showed attraction to the light. Artificial light at night in underpasses hypothetically increases the vulnerability of bats to road-mortality or to the barrier effect of roads. The most likely outcomes of lighting underpasses were 1. an increase in crossing rate above the freeway and a decrease under the underpasses, or 2. a reduction in crossing rate both above freeways and under the underpasses, when structures were lit. Our results corroborate those of studies on terrestrial mammals, and thus we recommend that underpasses intended to facilitate the movement of wildlife across roads should not be lit. • Insectivorous bats tend to avoid lit underpasses. • Artificial light at night in underpasses reduces their effectiveness as crossing structures. • Artificial light at night likely exacerbates the susceptibility of bats to road mortality and barrier effects. • If underpasses are to improve wildlife connectivity, we recommend not lighting them. [ABSTRACT FROM AUTHOR]

The extent of roads and other forms of linear infrastructure is burgeoning worldwide, but their impacts are inadequately understood and thus poorly mitigated. Previous studies have identified many potential impacts, including alterations to the hydrological functions and soil processes upon which ecosystems depend. However, these impacts have seldom been quantified at a regional level, particularly in arid and semi-arid systems where the gap in knowledge is the greatest, and impacts potentially the most severe. To explore the effects of extensive track, road, and rail networks on surface hydrology at a regional level we assessed over 1000 km of linear infrastructure, including approx. 300 locations where ephemeral streams crossed linear infrastructure, in the largely intact landscapes of Australia's Great Western Woodlands. We found a high level of association between linear infrastructure and altered surface hydrology, with erosion and pooling 5 and 6 times as likely to occur on-road than off-road on average (1.06 erosional and 0.69 pooling features km -1 on vehicle tracks, compared with 0.22 and 0.12 km -1 , off-road, respectively). Erosion severity was greater in the presence of tracks, and 98% of crossings of ephemeral streamlines showed some evidence of impact on water movement (flow impedance (62%); diversion of flows (73%); flow concentration (76%); and/or channel initiation (31%)). Infrastructure type, pastoral land use, culvert presence, soil clay content and erodibility, mean annual rainfall, rainfall erosivity, topography and bare soil cover influenced the frequency and severity of these impacts. We conclude that linear infrastructure frequently affects ephemeral stream flows and intercepts natural overland and near-surface flows, artificially changing site-scale moisture regimes, with some parts of the landscape becoming abnormally wet and other parts becoming water-starved. In addition, linear infrastructure frequently triggers or exacerbates erosion, leading to soil loss and degradation. Where linear infrastructure densities are high, their impacts on ecological processes are likely to be considerable. Linear infrastructure is widespread across much of this relatively intact region, but there remain areas with very low infrastructure densities that need to be protected from further impacts. There is substantial scope for mitigating the impacts of existing and planned infrastructure developments., (Copyright © 2017 Elsevier Ltd. All rights reserved.)