Vehicle-related Mortality Research Articles

Spatio-temporal variation of roadkills show mass mortality events for amphibians in a highly trafficked road adjacent to a national park, Costa Rica

Roads have detrimental impacts on wildlife populations around the world. Specifically, roads pose direct and indirect threats to wildlife by limiting dispersal movements or through vehicle-related mortality. The rate of wildlife mortality varies both in time and space depending on the landscape composition and the type and use of road infrastructure. The objective of this study was to investigate spatiotemporal variation of vertebrate mortality in a 4km segment of the 34 national road, adjacent to Carara National Park, Costa Rica. We conducted 81 roadkill surveys by car and bicycle from June 2010 to May 2011, georeferenced the locations of the kills and identified them to the lowest possible taxonomic level. We recorded a total of 4 709 road-killed animals of at least 58 species of vertebrates during the whole study. Amphibians accounted for 93.5 % of all the vertebrate losses and showed strong spatiotemporal variation of mass mortality events. Reptiles, especially snakes, were the second most affected taxon followed by mammals and birds. Relative mortality per day in the 4 km segment was 125.4 amphibians, 4.6 reptiles, 2.7 mammals, 1 bird and 0.46 undetermined. Road proximity to the border of the park, traffic volumes and lack of enforcement of speed limits may influence the high rate of roadkills found. We suggest the reinforcement of speed limits, wildlife crossing signage and the retrofitting of the existing culverts as under passes for animals to minimize vertebrate mortality at the road adjacent to Carara National Park.

Individuals matter: predicting koala road crossing behaviour in south-east Queensland

The ability to predict the frequency with which koalas (Phascolarctos cinereus) cross roads is an important step in developing mitigation strategies aimed at maintaining metapopulation viability for this species. In south-east Queensland, Australia, rapid urban development, including fragmentation and vehicle-related mortality, has contributed to a dramatic decline in local koala populations. Assessment of wildlife crossing structures that mitigates the impact of roads demonstrates these to be beneficial for many species. However, building enough structures to enable animals to move freely across impacted landscapes may be prohibitive in complex urban landscapes. The focus for this study was to consider the role of differing characteristics for species at risk. We examined the frequency of road crossings by individual koalas among six subpopulations in south-east Queensland. We explored the influence of potential predictor variables including: age, sex, and distance from roads. We established that road crossings were limited to a subset of individuals, with only 18 of 51 (~35%) koalas studied ever crossing a road. We found that koalas were disproportionately more likely to cross a road if they had initially been found within a distance of 100 m of that road. Males were more likely to cross roads than females, as were koalas aged less than five years. We suggest that successful wildlife road mitigation can be improved by better understanding the road-crossing behaviour of species such as the koala.

The association between alcohol restriction policies and vehicle-related mortality in Cali, Colombia, 1998-2008

Mena, J., Sánchez, Á., Gutiérrez, M., Puyana, J., & Suffoleto, B. (2014). The association between alcohol restriction policies and vehicle-related mortality in Cali, Colombia, 1998-2008. The International Journal Of Alcohol And Drug Research, 3(2), 149-158. doi:http://dx.doi.org/10.7895/ijadr.v3i2.157Aims: To determine whether the implementation of alcohol control policies was associated with changes in the incidence of road traffic deaths.Design: Ecologic study conducted using an interrupted time series analysis. Full restrictive polices banned alcohol between 6 p.m. and 6 a.m. Most restrictive polices prohibited alcohol between 1 a.m. and 10 a.m. Restrictive policies prohibited alcohol between 2 a.m. and 10 a.m. Moderately restrictive policies banned alcohol between 3 a.m. and 10 a.m. Lax policies prohibited alcohol between 4 a.m. and 10 a.m.Setting: We used data of road traffic mortality in the population of Cali, Colombia from 1998 to 2008.Participants: The population of Cali in 2008 was 2,184,753 inhabitants; 47% were male.Measures: Aggregated daily counts of road traffic deaths. Restrictive policies were compared with lax policies to estimate the effect of reducing hours of alcohol availability using multiple negative binomial regressions.Findings: There was a decreased risk of road traffic mortality in periods when moderately restrictive policies were in effect (IRR = 0.84, 95% CI 0.72–0.97, p = 0.019). There was an even lower risk of road traffic deaths in periods when most restrictive policies were in effect (IRR = 0.70, 95% CI 0.58–0.85, p < 0.001). In motorcyclists, most restrictive (IRR 0.55, 95% CI 0.38–0.81, p = 0.002) and full restrictive policies (IRR 0.52, 95% CI 0.29–0.94, p = 0.032) were associated with decreased risk of mortality.Conclusions: Our findings support more restrictive alcohol control policies to reduce road traffic mortality. Specifically, reducing the time of alcohol availability was associated with a decrease in road traffic death rates.

Vegetation moderates impacts of tourism usage on bird communities along roads and hiking trails

Bird communities inhabiting ecosystems adjacent to recreational tracks may be adversely affected by disturbance from passing tourism traffic, vehicle-related mortality, habitat alteration and modified biotic relationships such as the increase of strong competitors. This study investigated the effects of tourist usage of roads vs. hiking trails on bird communities in gorges of the Flinders Ranges, a popular South Australian tourist destination in the arid-lands.High tourist usage along roads decreased the individual abundance and species richness of birds relative to low usage trails. The decrease in species richness, though less pronounced, also occurred at high-usage sites along trails. Changes in the species response to recreational disturbance/impacts varied depending on the ecology of the species. Bigger, more competitive birds with a generalist diet were overrepresented at high-usage sites along roads and trails. Species using microhabitats in lower vegetation layers were more sensitive.However, structural and floristic complexity of vegetation was a more important factor influencing bird abundance than tourist usage. Sites with a better developed shrub and tree layer sustained higher species abundance and richer communities. Importantly, vegetation qualities moderated the negative effect of high usage on the individual abundance of birds along roads, to the extent that such an effect was absent at sites with the best developed shrub and tree layer.To protect avifauna along recreational tracks in arid-lands gorges, we recommend the closure of some gorges or sections for vehicle or any access. Further, open space particularly for camping needs to be minimized as it creates areas of high tourist usage with modified habitat that provides birds with little buffer from disturbance.

Status of northern mountain caribou (Rangifer tarandus caribou) in Yukon, Canada

Caribou (Rangifer tarandus) are an important ecological, cultural and economic resource in Yukon, Canada. Three caribou ecotypes occur within Yukon: Grant’s (R. t. granti), northern mountain (R. t. caribou), and boreal (R. t. caribou). Northern mountain caribou are classified as a species of special concern under Canada’s Species at Risk Act, and a national management plan for northern mountain caribou was recently completed. Twenty-six northern mountain caribou herds occur at least partially within Yukon, representing approximately 30,000 – 35,000 animals. Active monitoring of Yukon’s northern mountain caribou began in earnest in the early 1980s. To date, over 200 fall composition surveys have been carried out, over 1000 animals have been fitted with radio-collars, and nearly 40 formal population estimates have been completed. Disease and contaminant monitoring of these caribou has indicated relatively low disease prevalence and contaminant loading. Northern mountain caribou are harvested in Yukon, with an average of 230 caribou harvested per year by licensed hunters (1995 – 2012) and an unknown number by First Nation hunters. Future challenges related to caribou management and conservation in Yukon include increasing levels of industrial development primarily through mineral exploration and development, ensuring harvest of these herds is conducted sustainably given the absence of total harvest information, inter-jurisdictional management of shared herds, existing uncertainty surrounding herd distribution and delineation, and dealing with vehicle-related mortality of caribou for certain herds. Overall, the population status (i.e., trend) of eight herds is known, with two increasing, two decreasing, and four stable.

Vehicle-related mortality and road crossing behavior of the Florida panther

The Florida panther (Puma concolor coryi) is a relatively well studied species and it is well established that the most important threat to panthers include limited habitat area and continued habitat loss and fragmentation. Despite the recognition that roads result in panther mortality and may limit panther movement there has been very limited research on the importance of roads. In the current study panther telemetry data from 1981 until 2004, detailed road networks and vegetation maps were used to determine vehicle-related mortality and road crossing behavior of the Florida panther. Differences by age and gender were determined, as well as the effect of road size. Results indicate that vehicle collisions are a major threat to the Florida panther population, especially adult males. Major roads present a stronger barrier to movement than minor roads, and the movement of females is more affected than that of males. Road networks in south Florida have essentially segregated the movement of the sexes and have fragmented the limited remaining habitat of the Florida panther.

Evaluation of a pilot program in rural schools to increase bicycle and motor vehicle safety.

Concerned with high bicycle-and motor vehicle-related mortality rates among children, Idaho's South Central District Health Department provided a competition to increase use of 1) seat belts, 2) motor vehicle rear seating, and 3) bicycle helmets among children attending elementary schools in the eight rural counties it serves. Nine of the 44 elementary schools in the health district chose to participate in the contest. Eight schools addressed increasing helmet use, four schools also addressed increasing seat belt use and rear seating, and one school addressed safety in general. A $1,000 prize was awarded to each of four schools judged to have the highest levels of student and community involvement, outreach, creativity, and changes in safety behavior (based on perceptions of outside judges). In 1997, baseline observations were collected for 1) seat belt use and rear seating for children in 28 schools, and for 2) bicycle helmet use among children in 25 schools. In 1998, follow up data were collected for 1) seat belt and rear seating in 42 schools, and 2) bicycle helmet use in 35 schools. Data were analyzed using SAS. Adjusting for differences in baseline rates, regression analysis was used to compare 1997 and 1998 rates for seat belt use, rear seating, and bicycle helmet use for those schools having baseline data. Results showed that although there was no significant difference between participating and non-participating schools in rear-seating behaviors, there was an increase in seat belt and bicycle helmet use for participating schools. Since schools self-selected participation, it is unknown whether those schools were fundamentally different from nonparticipating schools.

Is motor vehicle-related mortality a disease of development?∗

The effect of economic development on motor vehicle-related mortality was assessed using per capital GNP from 46 countries, Gini coefficients from 34 countries and mortality statistics reported to WHO. The data suggest that these commonly used indicators of economic development do not reliably predict a given country's current experience with motor vehicle-related mortality. Implications for health planners and traffic safety workers are discussed.