Wildlife mortality caused by collisions with vehicles on roads is increasingly and effectively mitigated with exclusion fencing and crossing structures, but this solution potentially changes wildlife ...habitat use and distribution to increase the risk of mortality on adjacent, unmitigated railways. We investigated this potential side‐effect of mitigating the TransCanada Highway, which was completed in sections between 1983 and 2013, on the rate of wildlife mortality on the nearby transcontinental mainline of the Canadian Pacific Railway in Banff National Park. For each transportation class (highway and railway), we calculated collision rate as the number of collisions per year and km for two guilds (carnivores and ungulates) before and after mitigation occurred between 1981 and 2014. We constructed additional models for each transportation class and each of four species groups with adequate sample sizes: elk (Cervus canadensis), other ungulates (family Cervidae), bears (Ursus spp.), and coyotes (Canis latrans). Across guilds, mortality rates declined after mitigation, particularly on the highway (as expected) and most strongly for ungulates. For individual species groups, mortality on the railway for elk was best predicted by year and population size, without the inclusion of mitigation status on the adjacent highway. However, collision rates on the railway increased after mitigation for other ungulates (mostly deer, Odocoileus spp.) while also increasing over time. Collision rates on the railway increased over time for bears, but not in relation to highway mitigation. We found no evidence that the spatial distribution of collisions on the railway changed after highway mitigation, as might be expected from a funneling effect of crossing structures. Our results support and extend previous work demonstrating that exclusion fencing and wildlife crossing structures reduce wildlife mortalities on the highway at this location, and provide limited evidence, for other ungulates alone, that such mitigation may increase mortality on the adjacent railway. Similar analyses are warranted in other locations, particularly mountainous regions, where major transportation features often occur in close proximity.
Railway networks contribute to the direct mortality of wildlife through collisions with trains, which can threaten vulnerable wildlife populations even in protected areas, including grizzly bears ...(Ursus arctos) in Banff and Yoho National Parks, Canada. Mitigation to reduce bear-train collisions requires information about how grizzly bears use the railway spatially and temporally and how particular types of use might increase collision vulnerability. We used data from 27 grizzly bears fitted with global positioning system (GPS) collars between 2000 and 2016 to relate railway use by bears via resource selection functions to variables that described land cover, human use, and topography. We used the same suite of explanatory variables to distinguish pairs of 4 types of steps, in which 3 successive GPS points (with 2-hr fix rates) included ≥1 within 30 m of the rail (hereafter on) and 2 others that defined locations where bears effectively entered the railway (first fix off rail, next 2 on), crossed it (only the middle fix on the rail), continued along the railway (all 3 fixes on), or exited the railway corridor (first 2 on, last off). We compared both sites of higher use and each of these 4 step types to the relative frequency of bear-train collisions, predicting a positive correlation for continue step types. Relative to available locations, bears were more likely to use the railway close to railroad sidings (sections of twinned track where trains sometimes stop), at intermediate distances from human-use features (e.g., town sites, highways, trails), in areas with lower values of the compound topographic index (a proxy for wetness; within 500 m), and within 90 m of rugged terrain. Seasonally, bears made greater use of the railway in spring and fall. Among 1,515 sequences of 3 steps, crossing locations comprised >50% and were most distinct from continue locations (about 20%), which occurred in areas with more rugged terrain (within 300 m), closer to railway sidings, in spring and fall, and with steps that were 60% shorter. Contrary to our prediction, past reports of bear-train collisions were negatively correlated with continue locations and unrelated to overall use or any other movement type. Our results suggest that railway use by bears increased where it provided increased forage or easier travel, particularly in spring and fall, but more work will be needed to determine the mechanistic basis of bear-train collisions. Meanwhile, mitigation efforts such as habitat alteration or warning systems might target locations where past strikes are concentrated for grizzly bears or other sensitive populations.
The development and modernization of railway infrastructures in many countries has increased the frequency of wildlife-train collisions. Our objective was to describe the temporal pattern of train ...accidents related to wild ungulates (i.e., roe deer Capreolus capreolus, red deer Cervus elaphus, moose Alces alces, and wild boar Sus scrofa) to determine when the risk of collision is highest. We gathered data on train collisions with wild ungulates throughout Poland between 2012 and 2015 from Polish Railways Polskie Koleje Państwowe SA. We used generalized additive mixed models to investigate whether the number of collisions changed over time. The number of wildlife-train collisions varied depending on time of year. Most collisions occurred in autumn when animals form winter herds and migrate to and stay in winter refugia. The fewest collisions occurred in summer during breeding season. For all species except red deer, the number of collisions was significantly lower during weekends compared to weekdays. The distribution of collisions with regard to time of day was significantly different from simulated uniform random distribution, with peaks before dawn and after dusk, which reflect activity peaks of ungulates. During the day, the probability of collision was lower, with only single events observed between 0800 and 1600. We observed another collision-free period after midnight until 0400, probably because train traffic was minimal during this period. Most train collisions with ungulates took place in relatively narrow time windows in terms of time of year and time of day (i.e., 50% of the recorded cases took place in ∼17% of the total time observed). Consequently, mitigation measures of lowering speed limits can be applied during times when the risk of collision is highest.
Wildlife-train collisions (WTCs), particularly those with large mammals, pose a threat to the safety and continuity of rail operations. In this study, we collected 1,909 WTCs which took place in the ...Czech Republic between 2011 and 2019, in order to identify the most hazardous WTC locations and their spatial pattern. 208 WTC hotspots were identified using the KDE+ method. They contained 782 collisions (41.2%) and accounted for 0.7% of the Czech rail network length. We also identified and ranked the most important WTC hotspots using a collective risk parameter. WTCs occurred more frequently in the vicinity of a forest or stream and were more distant from arable land or urban/industrial areas than from other places on the entire Czech rail network. The results can help in placing crash-safety measures as a large proportion of accidents only occurred on less than 1% of the rail network.
•1,909 wildlife-train collisions (WTCs) were recorded between 2011 and 2019.•Roe deer were involved in 46% and wild boar in 36% of WTCs.•208 WTC hotspots were identified using the KDE+ method.•Large proportion of accidents (41%) occurred on less than 1% of the rail network.
Vegetation enhancement along railways has not been well studied, despite high rates of mortality from train strikes across numerous species, including sensitive populations in protected areas. This ...situation describes grizzly bears (Ursus arctos) in the mountain parks of Canada, where train strikes have become the leading source of known mortality. We hypothesized that attraction by bears to railways occurs partly because of increases in the richness, diversity, cover, and maturation rate of plants consumed by bears relative to adjacent forest and that this effect may increase with elevation. We quantified and compared responses in plants used by bears to the railway (ballast), forest edge, and within adjacent forest for two growing seasons (May–October) at 19 locations spanning an elevational gradient in Banff and Yoho National Parks in the Canadian Rocky Mountains. Overall, richness, diversity, and total cover of plants consumed by bears were greatest at the forest edge. On the forest edge or ballast, flowering rates of some species were over three times higher and fruit occurrence was up to five times higher than 50 m into the adjacent forest. Enhancement of berry productivity along rail edges increased with elevation. Buffaloberry (Shepherdia canadensis), an important regional pre‐hibernation resource, had more fruit, faster ripening, and higher sugar content for shrubs located within 15 m of the rail than within surrounding interior forest. Our results demonstrate that railway edges can increase the quantity and quality of palatable vegetation resources of both native and introduced species, potentially increasing strike risk for bears and other wildlife. Potential mitigation of this risk could include removal of attractants along the rail, particularly at locations where other factors increase the risk of collisions, and creation of forest openings, either through natural processes or through forest modification that would provide forage in less risky habitats.
To improve mitigation planning on railways, it is crucial to accurately assess the number of fatalities resulting from this type of infrastructure. To illustrate the relevance of considering the two ...main errors from the sampling process (searcher efficiency and carcass persistence), we corrected the estimation of mammal fatalities (> 1 kg) on a 750-km railway located in the Brazilian Savanna accounting for these errors. Observed fatalities were collected by two observers in a rail inspection vehicle (RV). We estimated searcher efficiency comparing the number of carcasses found during the searcher efficiency trials on foot and by RV on the same subsections of the railway. Carcass persistence was estimated based on trials with a subset of carcasses that had their persistence verified over three consecutive days. Searcher efficiency was 29.8% and daily carcass persistence probability was 99.7%. Nine surveys on the entire railway (2015–2016) recorded 1950 carcasses and, after correcting for the sampling errors, we estimated that 4286 mammals died on this railway in 23 months. This estimate is 2.2 times larger than the observed number of fatalities. These errors should not be neglected, as our results demonstrate that the number of observed carcasses is a misperception in relation to the true number of fatalities caused by the railway. However, our results also indicate that dealing with these errors in railway ecology is still a challenge. We stress the need to test more suitable sampling designs for fatality estimates on railways.
To better understand train collision mortality of moose (Alces alces) and elk (Cervus elaphus) in Ontario, we measured collisions along a 20 km segment of railway using post-winter railbed surveys ...(11 consecutive years), remote cameras, and radio-telemetered elk. We used these data to estimate provincial moose-train collision rates by extrapolating collision rates, moose density, and amount of high use railway per Wildlife Management Unit (WMU). The annual collision rate varied from 0 to 7 moose and 2 to 22 elk on the 20 km section of railway; the combined collision rate of moose and elk was highest in winters with above average snowfall. The extrapolated collision rates of moose indicated that ~1/3 of WMUs had a rate > 0.08 moose/km high use railway/yr; ~2/3 had a rate > 0.04. A conservative estimate of annual mortality was ~265 moose province-wide. Given that railway expansion is predicted globally, and specifically in Ontario, planning should include potential mitigation strategies that minimize ungulate-train collisions.
Despite the rapid advancements in the field of road ecology, very little research has been done in railway ecology. Basic research, such as railway use by wildlife, is relatively undocumented, albeit ...very important in understanding the potential negative and positive effects of railways on wildlife and ecosystems. We provide one of the first studies documenting wildlife railway use using motion-triggered cameras along a 20 km stretch of railway in Ontario. Our objectives were to develop a much-needed baseline understanding of railway use by endemic wildlife species, investigate differences in frequency of use among species, compare diurnal versus nocturnal use, and determine if railway use by wildlife was uniform or spatially varied. We found a significant proportion of medium-to-large resident mammalian fauna and several avian species non-uniformly using the studied railway. Some species used the railway as a travel corridor, while others appeared to use it incidentally. Diel and seasonal patterns of use were apparent for many species. Our findings emphasize the importance of species-specific investigations of railway ecology. The collection of baseline information on railway use by wildlife is critical in view of the dearth of available data, and we highly encourage further research in all aspects of wildlife–railway ecology.
PDF
