Copses are suitable for initial movement of common frog (Rana temporaria) in intensively utilised agricultural landscape

In intensively used agricultural landscapes, exposure to plant protection products (PPPs) has been identified as a potential threat to amphibians. Amphibians’ persistence depends on the availability of sufficient terrestrial habitats and is disproportionately sensitive to dispersal of juvenile. The initial juvenile movement phase, when individuals leave their natal ponds, represents the first terrestrial life stage at risk of direct PPP exposure, particularly when juveniles enter cultivated fields. During this phase, PPP-free habitats that are favoured for settlement could serve as an effective measure to protect amphibian populations. Therefore, we surveyed the movement phase via trapping of newly metamorphosed common frogs ( Rana temporaria ) at four ponds located in north-western Germany. The movement phase began in June and lasted about 30 days. At distances of 10 m and more, fewer individuals were captured than expected from trappings at pond banks, with trapping numbers decreasing by up to 94% at distances of 30 m from the natal ponds and more in agricultural areas than in copses. Generalised additive mixed modelling indicated that juvenile activity depends on regional minimum or mean temperature (> 16°C) and mean humidity (55–85%) at night and maximum temperature (~ 25°C) and minimum humidity (~ 55%) during the day. At distances of 10–30 m, the highest activity is expected in copses, in grassland during the night and in cereal fields during the day. Copses were highlighted as suitable habitats of newly metamorphosed juveniles, providing a stable microclimate on ground-level even under high temperature. These results emphasise the importance of copses and vegetation cover as potential buffer zones around ponds, especially given the ongoing local decline of the widespread European anuran species, Rana temporaria , and of the context of climate change.