scholarly journals Predicting spatial and seasonal patterns of wildlife-vehicle collisions in high-risk areas

2021 ◽  
Author(s):  
Hanh K.D. Nguyen ◽  
Jessie C. Buettel ◽  
Matthew W. Fielding ◽  
Barry W. Brook

AbstractContextVehicle collisions with wildlife can injure or kill animals, threaten human safety, and threaten the viability of rare species. This has led to a focus in road-ecology research on identifying the key predictors of ‘road-kill’ risk, with the goal of guiding management to mitigate its impact. However, because of the complex and context-dependent nature of the causes of risk exposure, modelling road-kill data in ways that yield consistent recommendations has proven challenging.AimHere we used a novel multi-model machine-learning approach to identify the spatio-temporal predictors, such as traffic volume, road shape, surrounding vegetation and distance to human settlements, associated with road-kill risk.MethodsWe collected data on the location, identity and size of each road mortality across four seasons along eight roads in southern Tasmania – a ‘road-kill hotspot’ of management concern. We focused on three large-bodied and frequently impacted crepuscular Australian marsupial herbivore species, the rufous-bellied pademelon (Thylogale billardierii), Bennett’s wallaby (Macropus rufogriseus) and the bare-nosed wombat (Vombatus ursinus). We fit the point-location data using ‘lasso-regularization’ of a logistic generalized linear model (LL-GLM) and out-of-bag optimization of a decision-tree-based ‘random forests’ (RF) algorithm.ResultsThe RF model, with high-level feature interactions, yielded superior results to the linear additive model, with a RF classification accuracy of 84.8% for the 871 road-kill observations and a true skill statistic of 0.708, compared to 61.2% and 0.205 for the LL-GLM.ConclusionsForested areas with no roadside barrier fence along curved sections of road posed the highest risk to animals. Seasonally, the frequency of wildlife-vehicle collisions increased notably for females during oestrus, when they were more dispersive and so had a higher encounter rate with roads.ImplicationsThese findings illustrate the value of using data-driven approaches to predictive modelling, as well as offering a guide to practical management interventions that can mitigate road-related hazards.

2009 ◽  
Vol 31 (2) ◽  
pp. 89 ◽  
Author(s):  
Ian F. Hayes ◽  
Ross L. Goldingay

The vast network of roads around the world has had a significant effect on wildlife and ecosystems through habitat fragmentation, reduced dispersal and mortality by collision with vehicles. Road agencies worldwide now frequently install dedicated structures to facilitate the safe crossing of roads by wildlife. We conducted surveys to determine the use of dedicated wildlife overpasses and nearby underpasses at two locations on the Pacific Highway in north-eastern New South Wales. Road-kill surveys were conducted to provide some understanding of the species commonly killed and whether the rate of road-kill was lower at one location where crossing-structures were located. Use of the crossing-structures by wildlife was monitored with sand-transects. The most frequent users were macropods, bandicoots and rodents. Macropods made greater use of overpasses (n = 104 tracks) than underpasses (n = 36), whereas underpasses were used more by bandicoots (n = 87) and rodents (n = 82) than were overpasses (n = 28, n = 15, respectively). We identified 78 road-kills of 21 species on two sections of the Pacific Highway over a 7-week period. Bandicoots (n = 16) and macropods (n = 9) were the most frequently observed victims. The mortality of wildlife was lower along the highway section with the crossing-structures (0.04 road-kills km–1) than it was along the highway section without structures (0.15 road-kills km–1). The lack of replication precludes any firm conclusion that the crossing-structures reduced road mortality but the high level of use of the crossing-structures by species that were common victims of road-kill suggests an influence.


Mammalia ◽  
2019 ◽  
Vol 83 (5) ◽  
pp. 487-495 ◽  
Author(s):  
Faraz Akrim ◽  
Tariq Mahmood ◽  
Shaista Andleeb ◽  
Riaz Hussain ◽  
Wendy Jane Collinson

Abstract The current study investigated the impact of roads on native wildlife fauna in Pothwar Plateau, Pakistan. By conducting driven transects over a period of 24 months (March 2012–February 2014), we identified 131 carcasses resulting from wildlife-vehicle collisions or “road kill”, comprising 18 vertebrate species from seven different orders. The Asiatic jackal (Canis aureus; Linnaeus, 1758) was the most common road kill (37.4%), followed by the small Indian mongoose (Urva auropunctatus; Hodgson, 1836; 9.9%) and the red fox (Vulpes vulpes; Linnaeus, 1758; 8.4%). Road kill incidences included both nocturnal (55.6%) and diurnal species (44.5%). The maximum number of road kills were encountered in the Rawalpindi district area (46.6%), followed by Chakwal (36.6%), Jhelum (8.4%) and Attock (8.4%). The majority of road kills occurred on paved roads (93.9%; 0.009 road kill/km) with significantly fewer occurrences on unpaved roads (6.1%; 0.004 road kill/km). Similarly, 77% (0.009/km) of the road kills were found adjacent to protected areas. The majority of road kills (33%) occurred during the spring (February–April) but less in summer (May–July) and winter (November–January) (19.8% for both). The study provides important data on road mortality of wildlife species in the region bordering protected areas in the Pothwar Plateau, Pakistan, to initiate management and conservation strategies.


2006 ◽  
Vol 33 (1) ◽  
pp. 5 ◽  
Author(s):  
Ulrike Klöcker ◽  
David B. Croft ◽  
Daniel Ramp

Kangaroo–vehicle collisions are frequent on Australian highways. Despite high economic costs, detrimental effects on animal welfare, and potential impacts on population viability, little research has been done to investigate the impact of road mortality on kangaroo populations, where and why accidents occur, and how the collisions can be mitigated. We therefore collected data on species (Macropus rufus, M. giganteus, M. fuliginosus, M. robustus), sex and age of kangaroos killed on a 21.2-km bitumenised section of outback highway over 6 months in far western New South Wales, Australia. The spatial and temporal distribution of road-killed kangaroos was investigated in relation to the cover and quality of road-side vegetation, road characteristics, the density of kangaroos along the road, climatic variables and traffic volume. A total of 125 kangaroos were found killed on the road at a rate of 0.03 deaths km–1 day–1. Grey kangaroos of two species (M. giganteus, M. fuliginosus) were under-represented in the road-kill sample in comparison with their proportion in the source population estimated during the day. No bias towards either sex was found. The age structure of road-killed kangaroos was similar to age structures typical of source kangaroo populations. Road-kills mainly occurred in open plains country. In road sections with curves or stock races, road-kill frequencies were higher than expected. Greater cover and greenness of roadside vegetation at the verge probably attracted kangaroos to the road and variation in this vegetation affected the spatial distribution of road-kills. The temporal distribution of road-kills was positively correlated with the volume of night-time traffic. The probability of a kangaroo–vehicle collision increased exponentially with traffic volume. Results are discussed in relation to the potential for mitigation of kangaroo–vehicle collisions.


Oryx ◽  
2021 ◽  
pp. 1-9
Author(s):  
Harry Olgun ◽  
Mzee Khamis Mohammed ◽  
Abbas Juma Mzee ◽  
M. E. Landry Green ◽  
Tim R. B. Davenport ◽  
...  

Abstract 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.


2020 ◽  
Vol 16 (7) ◽  
pp. 20200140 ◽  
Author(s):  
Fernanda Z. Teixeira ◽  
Trina Rytwinski ◽  
Lenore Fahrig

Roads and traffic impacts on wildlife populations are well documented. Three major mechanisms can cause them: reduced connectivity, increased mortality and reduced habitat quality. Researchers commonly recommend mitigation based on the mechanism they deem responsible. We reviewed the 2012–2016 literature to evaluate authors' inferences, to determine whether they explicitly acknowledge all possible mechanisms that are consistent with their results. We found 327 negative responses of wildlife to roads, from 307 studies. While most (84%) of these responses were consistent with multiple mechanisms, 60% of authors invoked a single mechanism. This indicates that many authors are over-confident in their inferences, and that the literature does not allow estimation of the relative importance of the mechanisms. We found preferences in authors' discussion of mechanisms. When all three mechanisms were consistent with the response measured, authors were 2.4 and 2.9 times as likely to infer reduced habitat quality compared to reduced connectivity or increased mortality, respectively. When both reduced connectivity and increased mortality were consistent with the response measured, authors were 5.2 times as likely to infer reduced connectivity compared to increased mortality. Given these results, road ecologists and managers are likely over-recommending mitigation for improving habitat quality and connectivity, and under-recommending measures to reduce road-kill.


2019 ◽  
Vol 3 (1) ◽  
Author(s):  
Mathieu Debure ◽  
Yannick Linard ◽  
Christelle Martin ◽  
Francis Claret

Abstract Silicate glasses are durable materials but laboratory experiments reveal that elements that derive from their environment may induce high corrosion rates and reduce their capacity to confine high-level radioactive waste. This study investigates nuclear-glass corrosion in geological media using an in situ diffusion experiment and multi-component diffusion modelling. The model highlights that the pH imposed by the Callovo–Oxfordian (COx) claystone host rock supports secondary-phase precipitation and increases glass corrosion compared with pure water. Elements from the COx rock (mainly Mg and Fe) form secondary phases with Si provided by the glass, which delay the establishment of a passivating interface. The presence of elements (Mg and Fe) that sustain glass alteration does not prevent a significant decrease in the glass-alteration rate, mainly due to the limited species transport that drives system reactivity. These improvements in the understanding of glass corrosion in its environment provide further insights for predictive modelling over larger timescales and space.


2019 ◽  
Vol 8 (2) ◽  
pp. 66 ◽  
Author(s):  
Raphaela Pagany ◽  
Wolfgang Dorner

Wildlife–vehicle collisions (WVCs) cause significant road mortality of wildlife and have led to the installation of protective measures along streets. Until now, it has been difficult to determine the impact of roadside infrastructure that might act as a barrier for animals. The main deficits are the lack of geodata for roadside infrastructure and georeferenced accidents recorded for a larger area. We analyzed 113 km of road network of the district Freyung-Grafenau, Germany, and 1571 WVCs, examining correlations between the appearance of WVCs, the presence or absence of roadside infrastructure, particularly crash barriers and fences, and the relevance of the blocking effect for individual species. To receive infrastructure data on a larger scale, we analyzed 5596 road inspection images with a neural network for barrier recognition and a GIS for a complete spatial inventory. This data was combined with the data of WVCs in GIS to evaluate the infrastructure’s impact on accidents. The results show that crash barriers have an effect on WVCs, as collisions are lower on roads with crash barriers. In particular, smaller animals have a lower collision share. The risk reduction at fenced sections could not be proven as fenced sections are only available at 3% of the analyzed roads. Thus, especially the fence dataset must be validated by a larger sample number. However, these preliminary results indicate that the combination of artificial intelligence and GIS may be used to analyze and better allocate protective barriers or to apply it in alternative measures, such as dynamic WVC risk-warning.


2019 ◽  
Vol 37 (27_suppl) ◽  
pp. 201-201
Author(s):  
Tara L. Kaufmann ◽  
Katharine A. Rendle ◽  
Erin Aakhus ◽  
Andrea Bilger ◽  
Peter Edward Gabriel ◽  
...  

201 Background: Unplanned acute care is debilitating and burdensome for patients with advanced cancer and their caregivers. There is a pressing need to understand how available evidence-based practices (EBPs) to reduce acute care 1) align with the needs and priorities of patients and 2) are best implemented within large health systems. We are conducting a mixed methods study to assess patient- provider- and system-level factors that shape the decision to seek acute care during active cancer treatment in order to select and adapt EBPs for implementation. Here we present data from patients’ perspectives. Methods: Purposive sampling approach to identify solid tumor cancer patients on active treatment with unplanned acute care events at a large health system from Aug 2018-Jan 2019. We conducted semi-structured interviews to elicit patients’ perspectives on factors that shape their decision to seek acute care and to inform intervention strategies. Results: Forty-nine patients participated in this study. We identify several patient factors that intersect with the decision to seek care: self-management behaviors, guilt, negative ED perception, safety concerns, and trust. Patients attempt self-management prior to contacting their oncology team, which introduces variability in the duration and severity of reported symptoms. Delay is related to patients’ guilt for burdening their oncology team and to provider accessibility. Patients describe a high symptom threshold to seek care that is often coupled with a negative perception of the ED, but do prefer in-person evaluation for new and distressing symptoms for safety. They express a high level of trust in the oncology team and relative distrust of non-oncology providers. Conclusions: Our data suggest a conceptual model for patient factors that drive unplanned acute care. Patients identify three areas for improvement: 1) enhanced peer support and education to manage uncertainty about cancer treatment; 2) accessible portals for patient-clinician communication; and 3) home or clinic-based after-hours oncology symptom management. Interventions to target these needs should address patients’ emotional concerns and be well integrated within the oncology team.


2004 ◽  
Vol 31 (1) ◽  
pp. 83 ◽  
Author(s):  
Brendan D. Taylor ◽  
Ross L. Goldingay

Although vehicle-induced mortality of wildlife is well known on roads throughout Australia, few empirical studies describe the extent of this mortality or assess the potential effects on wildlife populations. We recorded 529 roadkills of 53 vertebrate species along a 100-km circuit of three major roads during 20 weekly surveys across winter, spring and summer. This equates to 0.3 road-kills km–1 week–1 or one road-kill every 3.8 km week–1. The most frequently killed native species were the northern brown bandicoot (4 per week), the mountain brushtail possum (2 per week) and the Australian magpie (2 per week). These values are underestimates because our survey technique could not detect all road-kills and ~40% of those left on the roadside disappeared within 7�days. Detailed study of the local population of the brown bandicoot is needed to determine whether such a level of road mortality is sustainable.A logistic regression analysis was used to determine whether any of 10 road and landscape attributes were closely associated with the presence of specific groups of road-kills. Bandicoots were not associated with any measured attributes. Possums were more likely to occur along roads on mid-slopes and ridge-tops. Magpies were associated with roads on ridge-tops. Canopy-dwelling birds were more likely to be killed on 3-lane roads surrounded by dense vegetation.Road-kill surveys such as this are needed to identify species for which road mortality is unsustainable, to determine the influence on threatened species, and to identify important crossing points where road-kills are high. The frequency of road-kill of many ground-dwelling or arboreal mammal species in this study highlights the importance of impact mitigation by road authorities.


Sign in / Sign up

Export Citation Format

Share Document