11 Nov We successfully completed the autumn monitoring of amphibians on the roads in 2020
Amphibians are heavily dependent on different types of habitats and migrate among them on an annual basis. The most noticed are spring migrations to breeding sites since some species are explosive breeders and they all migrate almost simultaneously. The autumn migration to hibernation sites is more dispersed and takes place at different times. During the spring and autumn migrations, amphibians are frequently victims of the roadkills because roads often intersect their traditional migratory routes.
On the project road sections where the amphibian hotspots of road mortality have been detected, we plan to implement mitigation measures, which include tunnels and guiding fences. Guiding fences prevent amphibians from crossing the road and at the same time direct them to tunnels through which they can safely migrate between different habitats throughout the year.
To determine the best positions for the tunnels and permanent fences on the roads, it is necessary to conduct preoperational monitoring on roads in the spring and autumn. The autumn survey is especially important for our project target species – Italian crested newt since the latest research suggests highest road activity for crested newts in this time of the season. During the autumn monitoring, we often notice juvenile specimens that migrate to wintering grounds after a successful metamorphosis.
Autumn migrations in 2020 were monitored on three road sections in the Ljubljansko barje and the road section in Radensko polje. Surveys were conducted in 5 nights with favourable weather conditions for amphibian migration. In both project areas, we recorded the activity of target species – Italian crested newt and yellow–bellied toad – on the roads. Also, other species are found in the areas and migrate to hibernation sites during this season (European tree frog, agile frog, common frog, common newt, common toad and green frogs). In the Ljubljansko barje, we recorded on the roads almost 1200 amphibians with the most common species, the common newt. In Radensko polje we detected almost 2900 amphibians, among which predominated the common toad.
Photo: Tina Stepišnik, Katarina Drašler