Daytime driving decreases amphibian roadkill

Abstract

Roadkill has gradually become a common factor that has contributed to the decline of amphibians, and traffic volume is an important parameter that can be used to determine the impacts of roads. However, few researchers have studied the effects of either daily or nightly traffic volume on amphibian roadkill in China. Hence, as an essential step for implementing mitigation measures, we conducted 77 road surveys along 10 km of road in the Wanglang National Nature Reserve (NNR) to determine the temporal and spatial distribution patterns of amphibian road mortality. In total, 298 dead individuals (Bufo andrewsi and Rana chensinensis) were observed on the road from April to October in 2017 and during June and August in 2015 and 2016. B. andrewsi had the highest number of records (85.2%) and was more vulnerable to road mortality than R. chensinensis. Amphibian fatalities mainly occurred during the breeding season in April, but there was an additional concentration of B. andrewsi roadkill in June and July. There was a significantly positive correlation between amphibian road mortality and mean night-time traffic volume. Roadkill hotspots were non-randomly distributed throughout the study area and were mainly concentrated in the road sections near the breeding pools. Therefore, to effectively mitigate the effects of road mortality in the Wanglang NNR, measures should be implemented both during hot moments and at hotspots. First, based on roadkill hot moments, during the breeding season (in April) and in June and July, the Wanglang NNR should establish temporary traffic restraints at night. Second, based on roadkill hotspots, culverts should be established in areas near breeding pools adjacent to roads, and barrier walls should be installed to guide amphibians into the culverts.

Impact of highway on vertebrate roadkill in Nam Nao National Park, Thailand

“…The increasing numbers of vehicles and the nighttime played significant roles in the intensity of road mortality in our study. This result was in line with Zhang et al (2018) who found a significant positive correlation between road mortality of amphibians and the average number of vehicles during the night.…”

“…Our study over 12 months from August 2018 through July 2019 for 34 days collected 1,391 roadkilled individuals along the 1,275 kilometers of the 44-km road in NNNP. We believe this number is underestimated due to our witnessing scavengers and birds of prey feeding on carcasses, as also reported by Zhang et al (2018). We also observed carcass disintegration and removal from the road due to high traffic volume and vehicle speed, as confirmed by Hobday (2010).…”

Spatio-Temporal Patterns and Consequences of Road Kills: A Review

“…As a result, these animals are susceptible to a vehicle collision. On the other hand, traffic density and driving speed will influence the extent of this risk [ 2 , 23 , 61 ]. As a result, when and where road kills occur is the product of several integrated influencing factors.…”

“…Yet, there are still humid conditions, which soften the carcass’s body, thereby increasing roadkill removal rates [ 91 ]. Heavy rainfall often deters scavengers from the roads, thereby perpetuating carcass persistence [ 61 , 91 ]. Besides, these heavy rains can also speed up the degradation of the road kill and wash away the remnants of its body [ 119 ].…”

Coastal road mortality of land crab during spawning migration

“…Notably, the differences in road mortality are influenced by the movements associated with reproduction 30 . For example, amphibians experience frequent roadkill near breeding ponds during spring migration for spawning 34 , 35 . Land crabs are especially vulnerable because of the synchronized release to zoeae if there are coastal roads.…”