Wendy Collinson

Wildlife road traffic accidents: a standardized protocol for counting flattened fauna

Previous assessments of wildlife road mortality have not used directly comparable methods and, at present, there is no standardized protocol for the collection of such data. Consequently, there are no internationally comparative statistics documenting roadkill rates. In this study, we used a combination of experimental trials and road transects to design a standardized protocol to assess roadkill rates on both paved and unpaved roads. Simulated roadkill were positioned over a 1 km distance, and trials were conducted at eight different speeds (20–100 km·h−1). The recommended protocol was then tested on a 100-km transect, driven daily over a 40-day period. This recorded 413 vertebrate roadkill, comprising 106 species. We recommend the protocol be adopted for future road ecology studies to enable robust statistical comparisons between studies.

Wildlife roadkill patterns on a major highway in northern Tanzania

Despite expanding road networks, there is limited understanding of the effects of roads on wildlife in East Africa. We present a baseline survey and describe the patterns of roadkill in the Tarangire—Manyara ecosystem of Tanzania. A 75 km stretch of the Arusha Highway that passes adjacent to Manyara Ranch and Lake Manyara National Park was studied for 10 consecutive days in November 2013 (the rainy season). Wildlife species killed on the road, roadkill frequency and road characteristics were determined. A total of 101 roadkill were recorded (0.13 roadkill km-1) comprising 37 species from all terrestrial vertebrate groups, of which two species, house cat (Felis catus) and domestic dog (Canis lupus), were domesticated species. Birds were the most frequently killed taxon (50%), followed by mammals (30%), reptiles (17%) and amphibians (3%). Excluding birds, roadkill primarily consisted of nocturnal species (65%) versus diurnal species (35%). Most roadkill (77.3%) were encountered on road stretches adjacent to protected areas of Manyara Ranch and Lake Manyara National Park compared with 22.7% on the road stretches adjacent to non-protected areas. These findings highlight that roads are a potential threat to wildlife in East Africa and serve as a baseline for future comparisons.

Testing the Value of Citizen Science for Roadkill Studies: A Case Study from South Africa

Roads impact wildlife through a range of mechanisms from habitat loss and decreased landscape connectivity to direct mortality through wildlife-vehicle collisions (roadkill). These collisions have been rated amongst the highest modern risks to wildlife. With the development of ‘citizen science’ projects, in which members of the public participate in data collection, it is now possible to monitor the impacts of roads over scales far beyond the limit of traditional studies. However, the reliability of data provided by citizen scientists for roadkill studies remains largely untested. This study used a dataset of 2 666 roadkill reports on national and regional roads in South Africa (total length ~170 000 km) over three years. We first compared roadkill data collected from trained road patrols operating on a major highway with data submitted by citizen scientists on the same road section (431 km). We found that despite minor differences, the broad spatial and taxonomic patterns were similar between trained reporters and untrained citizen scientists. We then compared data provided by two groups of citizen scientists across South Africa: 1) those working in the zoology/conservation sector (that we have termed ‘regular observers’, whose reports were considered to be more accurate due to their knowledge and experience), and 2) occasional observers, whose reports required verification by an expert. Again, there were few differences between the type of roadkill report provided by regular and occasional reporters; both types identified the same area (or cluster) where roadkill was reported most frequently. However, occasional observers tended to report charismatic and easily identifiable species more often than road patrols or regular observers. We conclude that citizen scientists can provide reliable data for roadkill studies when it comes to identifying general patterns and high-risk areas. Thus, citizen science has the potential to be a valuable tool for identifying potential roadkill hotspots and at-risk species across large spatial and temporal scales that are otherwise impractical and expensive when using standard data collection methodologies. This tool allows researchers to extract data and focus their efforts on potential areas and species of concern, with the ultimate goal of implementing effective roadkill-reduction measures.

An Inventory of Vertebrate Roadkill in the Greater Mapungubwe Transfrontier Conservation Area, South Africa

Using a standard protocol, we conducted vertebrate roadkill surveys in the Greater Mapungubwe Transfrontier Conservation Area (GMTFCA), South Africa, which is a World Heritage Site. A total of 991 roadkill were recorded on the paved roads and 36 roadkill on the unpaved roads. Identifiable roadkill comprised 162 species from 24 orders and 65 families. Ninety-three roadkill could not be identified to species level. Roadkill counts were strongly influenced by road type and season. More roadkill was recorded on the paved than the unpaved roads. Irrespective of road type, the proportion of roadkill was greatest in the hot/wet season (4.3 paved roadkill/km/day paved and 1.3 roadkill/km/day unpaved) and lowest in the cold/dry season (2.0 roadkill/km/day paved and 0.1 roadkill/km/day unpaved). The high numbers of vertebrates identified as roadkill suggests that road traffic has the potential to directly and negatively affect biodiversity conservation in this part of South Africa. We recommend continued roadkill data collection across South Africa to assist with creating an inventory of species most likely to be at risk from roads. This will, in turn, better inform the implementation of potential mitigation measures.

Driver Knowledge and Attitudes on Animal Vehicle Collisions in Northern Tanzania

Roads are a major cause of wildlife mortality by animal-vehicle-collisions (AVCs). We monitored the patterns and frequency of AVCs on two sections of a major highway in Northern Tanzania and compared these patterns to the knowledge and perceptions of drivers who frequently use the roads. While actual field survey showed that more birds were killed by AVCs, mammals were perceived by the drivers to be the most common AVC. Drivers were indifferent to whether AVCs were a major problem on the road, and 67% strongly felt that AVCs were mainly accidental, either due to high vehicle speed or poor visibility at night. There was a negative correlation between the likelihood of a species being hit by vehicles and its average body mass. Only 35% of drivers said they had attended an educational program related to the impact of roads on wildlife. This study highlights a need for collaborative efforts between the wildlife conservation and road departments to educate road users on the importance of driving responsibly and exercising due care for wildlife and human safety. This should be coupled with effective mitigation measures to reduce the extent of AVCs.