In collaboration with Caltrans biologists, traffic safety liaison, maintenance staff and engineers, Animex International has been developing a solid wildlife barrier that can be attached to existing standardized western guardrail systems to prevent wildlife from getting onto roads.

Solid barriers have been proven to be more effective at excluding amphibians from the highway and encourage them to move towards wildlife crossing structures quicker than highly transparent mesh materials.

The pilot project site has very limited embankment for a secondary wildlife fence so the team decided to investigate the possibility of attaching a wildlife exclusion barrier to the existing guardrail.

Animex has designed and installed a similar system in Ontario Canada that has proven to be successful in guiding various animals to a wildlife underpass in a wetland. The team has been adapting this existing design to meet the safety requirements of Caltrans.

The current proposals are due to be reviewed by the new products committee and initial discussions and adaptations have included the following considerations:

Dimensions (height/section length/thickness)
Material type
Fasteners
Drainage
Maintenance and repairability
Loading
Installation

If the approval process is successful the team will look to install and monitor the system in the District 5 region and hope it will enable other projects across the state and wider USA to adopt and utilize the same solution quickly and efficiently.

In this presentation, we will provide an insight into the history of the project, share technical developments and explore the challenges we have overcome so far.

The impact of roads on amphibians is now widely known, and despite the mitigation programmes that have been implemented for decades, most measures remain poorly investigated. Not only is there a real lack of feedback on these solutions, but existing studies strongly vary in terms of methodology.
The Cerema (Centre for Studies and Expertise on Risks, the Environment, Mobility and Urban Planning) is collaborating with various stakeholders to compile existing information on mitigation measures carried out for amphibians in France into standardized feedback sheets. In addition, we are proposing a effectiveness assessment protocol that can be applied at a national scale using camera traps and AI. We describe the trade-offs in terms of study cost, material (number of devices, location, batteries), quantity and quality of images obtained.
We rely on the high-frequency images provided by camera traps to monitor activity during migration to aquatic breeding habitats, and we focus on a variety of sites. One system used in the North East of France is a double-way tunnel with results available for the first two years of use after construction. The second system is used in South Eastern France and consists of multiple one-way tunnels, in which we created a small support device for camera traps. We also established a scientific partnership to develop a computer algorithm for sorting images, that will allow us to expand this unique protocol at any site. Another perspective is to implement optimized protocols for the attractiveness of crossing and the monitoring of mortality.

Road mortality of Amphibians is widespread problem also in Czechia. We register about 620 problematic road sections all over country. The most affected species are Common Toad (Bufo bufo) and Common Frog (Rana temporaria). We established evaluation of road sections based on regular field monitoring; ones that are more problematic are visited more often than less important ones. There are 7 categories based on mortality magnitude combined with solution accepted. Problematic ones are risky sections with mortality 50 to 500 animals and critical ones with mortality higher than 500 animals. On other hand, we have resolved sections where permanent barriers were built and secured ones where temporary ones are built regularly. Unfortunately, their proportion is relatively small especially in case of resolved road sections because not many were build and some of them are destroyed already. Our agency tries to change it and improve situation by issuing standards for building barriers and helping with financing of works also. We are facing several new problems. Formerly really numerous populations of Common Toad shrink from thousands to tens, without any obvious reason on many localities. Spring migration were affected strongly by severe droughts in last years. In addition, timing of migration changed strongly – it started about one month earlier this year. Moreover, we found that newts are migrating much earlier than frogs and toads what was not known and expected. Despite that are hundreds of thousands individuals saved every year what is good news.

We evaluated the distribution of reptiles across a fauna-designed overpass and its surroundings, crossing a major highway south of Gothenburg, Sweden. We used 80 Artificial Cover Objects (ACOs) for inventory and monitoring of reptile distribution. The ACOs were comprised of plywood coverboards placed in a system of positions along transects parallel with the highway and across the overpass. We used Generalized Linear Mixed Effects Models (GLMM) with a negative binomial distribution to analyze reptile counts in relation to the highway and the fauna overpass, while controlling for percent vegetation cover, shadiness and ambient air temperature.

We made 58 monitoring visits, generating 4505 observations beneath AOCs between 2018 and 2023. On 275 occurrences did we detect reptiles of five species; 10 grass snakes (Natrix natrix), 35 smooth snakes (Coronella austriaca), 14 sand lizards (Lacerta agilis), 3 viviparous lizards (Zootoca vivipara), 213 slowworms (Anguis fragilis).

The most parsimonious of our candidate models supported the “Connectivity hypothesis”, i.e. variation in reptile counts was best explained without discriminating between the fauna overpass and surrounding reference areas, while controlling for year, vegetation cover, shadiness, and ambient temperature (ΔAICc=0.00 and AICc weights=78%). Reptile counts was higher at AOCs with lower degree shadiness. The highly endangered sand lizard (Lacerta agilis) was identified under ACO on the fauna overpass only one year after its establishment. In addition, the vulnerable smooth snake (Coronella austriaca), was found on the overpass. Our results stress that management of suitable habitats is crucial across fauna passages, to function for reptiles.

Roads have several negative ecological effects on bats. Clutter-adapted bat species avoid roads as the open space increases the risk of predation. This results in the road acting as a barrier of movement, making otherwise suitable habitat inaccessible. Different approaches to mitigate the fragmentation and mortality caused by roads have been explored. Underpasses such as bridges or tunnels have proven to be used by clutter-adapted species to cross the road. A few studies have indicated that some species of bats could possibly use smaller structures such as pipe culverts. As pipe culverts are more cost-effective than bridges and tunnels, we set out to quantitively investigate what factors affect the usage of pipe culverts, aiming to produce recommendations for their implementation in the landscape. Clutter-adapted bats were surveyed with ultrasound detectors in 269 pipe culverts in Sweden. Each pipe culvert was surveyed for one night each and 73 pipe culverts with a high recorded activity were revisited and surveyed with mist nets. M. brandtii, M. daubentonii, M. mystacinus, M. nattereri, and P. auritus were found to be flying in the pipe culverts. Factors affecting the activity and usage of the pipe culverts were the width of the pipe culverts, presence of water in the pipe culvert and the presence of forest at the openings of the pipe culvert. The results give insight into how pipe culverts could be designed and implemented in landscape planning to mitigate the fragmentation caused by roads and decrease their negative effects on clutter-adapted bats.

The impact of noise on bats is poorly understood and can lead to requirements for mitigation that are ineffective,expensive and/or unnecessary. These can include onerous measures such as acoustic fencing or lengthy restrictions on working practices or schedules. This lack of understanding is due, in part, because noise measurements are weighted to suit human hearing and not that of bats, over-emphasising sounds bats cannot hear and ignoring sounds that they can. A project to build the UK's second high-speed rail link (High Speed 2) took high-frequency unweighted measurements of different construction activities in order to better understand the distances over which noise impacts should be considered. These data were published in publicly available guidelines published by the Chartered Institute for Ecology and Environmental Management (CIEEM). A template for assessing noise impacts in different scenarios was also developed. In this presentation, the reasons and need for appropriate noise measurements is explained, the type of data that can be collected/referenced is shared, and an approach to risk assessment is suggested. The aim of sharing construction noise data and the associated approach to risk assessment is to ensure evidence-based, cost-effective, pragmatic mitigation (such as seasonal restrictions and buffer distances) are recommended during construction activities only when needed.