Understanding spatio-temporal patterns of deer-vehicle collisions to improve roadkill mitigation

Does expanding wild venison consumption substitute livestock meat consumption? Evidence from the demand systems analysis of meat products in Hokkaido, Japan

In many countries, growing deer populations cause environmental, economic, and traffic safety problems. This study sheds light on the potential implications of expanding the consumption of venison from hunted wild deer through deer population management efforts. It focuses on changes in environmental impacts resulting from changes in the demand for livestock meat due to increased consumption of wild venison. We analyzed the demand system between them using the Quadratic Almost Ideal Demand System (QUAIDS) model and scanner data from a grocery store chain in Hokkaido Prefecture, Japan. The results show that wild venison is a substitute good for pork and lamb. By contrast, wild venison is a complementary good for imported and domestic beef. Based on the estimated demand system model, we conducted an environmental footprint analysis to estimate the changes in environmental impacts when venison consumption increased. This shows that the greenhouse gas, water, and land footprints would increase, indicating greater environmental impacts, under a scenario of expanded venison consumption. The results demonstrate that increased venison consumption does not necessarily reduce the net environmental impacts of meat consumption, which depends on the demand system for meat products and the environmental footprint intensities of the respective products.

Better safe than sorry - Understanding the attitude and habits of drivers can help mitigating animal-vehicle collisions

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.

Predictive Modeling of Ungulate-Vehicle Collision in the Republic of Korea

Animal-vehicle collisions (AVC) threaten animals as well as human life and property. AVC with ungulates, called ungulate-vehicle collision (UVC), often seriously endangers human safety because of the considerable body size of ungulates. In the Republic of Korea, three ungulate species, Capreolus pygargus, Hydropotes inermis, and Sus scrofa, account for a large proportion of AVC. This study aimed to understand the characteristics of UVC by examining various parameters related to habitat, traffic, and seasonality using MaxEnt. The results showed that the peak UVC seasons coincided with the most active seasonal behaviors of the studied ungulates. For the modeling results, in C. pygargus, habitat variables are most important for models across seasons, and UVC events are most likely to occur in high mountain chains. In H. inermis, habitat and traffic variables are most important for models across seasons. Although the important habitat for the models were different across seasons for S. scrofa, the maximum speed was consistently critical for models across all seasons. Factors critical to UVC in the Republic of Korea were different for the three ungulate species and across seasons, indicating that seasonal behavior should be considered along with landscape and traffic characteristics to mitigate UVC.

Spatial and temporal trends in western polecat road mortality in Wales

Roads have considerable ecological effects that threaten the survival of some species, including many terrestrial carnivores. The western polecat is a small-medium sized mustelid native to Asia and Europe, including Britain where its historical stronghold is in Wales. Polecats are frequently killed on roads and road casualties represent the most common source of data on the species in the UK. However, little is known about the factors that increase the risk of collision. We used Generalized Additive Models to explore seasonal patterns in collisions as well as using Principal Component Analysis and regression modelling to identify landscape characteristics associated with polecat road casualties in Wales. Polecat road casualties had a bimodal distribution, occurring most frequently in March and October. Casualties were more frequently associated with road density, traffic volume, presence of rabbits, habitat patchiness and the abundance of proximal improved grassland habitat. Casualties were negatively associated with elevation and the abundance of semi-natural grassland habitat. The results of this study provide a framework for understanding and mitigating the impacts of roads on polecats in their historic stronghold, hence has considerable value to polecat conservation as well as broader applicability to ecologically similar species.

Forecasting seasonal peaks in roadkill patterns for improving road management

For several species, roadkill is not spatially aggregated on hotspots, having instead a more diffuse pattern along the roads. For such species, management measures such as road passages may be insufficient for effective mitigation, since a large part of the road crossings is likely to occur outside the influence of those structures. One complementary approach could be to implement temporary mitigation actions, such as traffic calming. This requires understanding when roadkill peaks may occur. We tested the feasibility of predicting seasonal peaks of roadkill using data from a 3-year systematic monitoring (78 surveys over ca. 960 km of roads) from eight non-flying vertebrate species from Mato Grosso do Sul, Brazil, with different body size and life history traits (ca. 6400 records from focal species). We modelled the time-series of the roadkill of these species at large scale (state level) using generalized additive mixed models (GAMMs). We used the data of the first 2 years as training datasets, and the information from the third year of surveys as testing datasets to evaluate the prediction performance of models. Overall, the models of species feed with a higher number of records were able to follow reasonably well the variations of roadkill over time, although they were not able to correctly predict the number of collisions. For species with fewer observations, the models presented a poorer goodness-of-fit and prediction ability. Our results suggest that, at least for those species with higher roadkill rates, it can be possible to forecast periods of higher probability of occurring hot-moments of mortality. Such models can provide valuable information to implement seasonal management actions.

Characteristics of kangaroo-related motor vehicle crashes

BACKGROUND

Kangaroo-related motor vehicle collisions are common but there is limited literature on this topic. Drivers confronted by kangaroos may choose to swerve or to directly collide with the kangaroo. The effect of these differing crash mechanisms, along with the effect of vehicle type or time of day, has not yet been reported.

METHODS

A retrospective cohort study was performed, examining patients admitted to our tertiary trauma centre for kangaroo-related motor vehicle collisions between 2000 and 2020. Data on patient demographics, crash characteristics, and hospital stay were collected and analysed.

RESULTS

A total of 366 patients were included and were predominantly male (76%) with an median age of 40. Swerve crashes were more common (59%) than direct impact and swerving was a statistically significant predictor of reduced injury severity score on multivariable analysis (other significant factors were female sex and no rollover). Motor vehicle crashes and motorbike crashes had differing crash characteristics. Motor vehicle crashes were more likely the result of swerving, and swerving was less likely to cause ejection or require extrication but more likely to cause rollover. Motorbike crashes however, were more likely the result of head on collision and riders were more likely to be ejected from the vehicle, require extrication, or be involved in a rollover. In terms of time of day, there were more crashes at dawn and there was a trend towards higher injury severity score and length of stay for night-time crashes.

CONCLUSION

For kangaroo-related motor vehicle crashes, predictors of increased injury severity score on multivariable analysis were male sex, direct impact, and rollover. Motorbikes and motor vehicles had differing crash mechanisms and characteristics, as did night-time crashes when compared to daytime or twilight crashes.

LEVEL OF EVIDENCE

IV, prognostic.

Deer Rescue in Tuscany: Retrospective Analysis and Assessment of Radiography Diagnoses

Simple Summary

Animal-vehicle collisions are the major cause of rescue and need for hospitalization in wildlife referral centers. Radiography is used to assess the traumatized animal and is a rapid means to evaluate various traumatic pathologies. Clinicians can exploit radiography when making rapid decisions about whether to euthanize or treat an animal. We evaluated data (reasons for rescue, diagnosed lesions, and outcome) from a population of hospitalized wildlife ungulates and we investigated the benefits of using radiography as a diagnostic tool.

Abstract

Animal-vehicle collisions are the major cause of rescue and need for hospitalization in wildlife referral centers. Clinicians need easy-to-use tools to make rapid decisions about whether to euthanize or treat injured animals. The aim of the study was to evaluate the data (reasons for rescue, diagnosed lesions, and outcome) from a hospitalized population of wildlife ungulates and investigate the benefits of using radiography as a diagnostic tool. Data were collected from three wildlife referral centers in Tuscany (Italy). The following information was collected for each animal: reason for hospitalization, clinical examination, radiographic examination, definitive diagnosis, and outcome. A chi-squared test was used to assess the benefits of radiography in detecting different traumatic lesions. Prevalence was reported according to the reason for hospitalization, definitive diagnosis, radiographic diagnosis, and outcome. The main reason for hospitalization was traumatic lesions due to vehicle collisions and 71.1% of the animals did not survive. Radiography was more useful in patients with traumatic axial skeletal lesions and/or multiple traumas with respect to traumatic appendicular skeleton lesions. Our results show that radiography is a useful diagnostic technique for assessing wildlife emergencies and it could help the clinician in making medical decisions.