Combining telemetry and fluorescent pigments to study the use of terrestrial habitats by a declining amphibian, the common spadefoot toad (Pelobates fuscus)

The common spadefoot toad ( Pelobates fuscus ) is a declining amphibian whose movement patterns and terrestrial habitat use are not well known. The daily positions of 51 common spadefoot toads were monitored by telemetry at two sites along the Lower Rhine valley, France. Fluorescent pigments were used to monitor the nocturnal movements of 91 individuals in three populations in the same area. This study aimed to (i) characterise terrestrial movement patterns and estimate home ranges, and (ii) identify the preferred habitat types of this fossorial amphibian. The median home range size was 0.35 ha. We counted an average of 6.9 burrows per individual and individuals spent an average of 2.7 days in a burrow. The average distance travelled in 24 h was 12.5 m with a maximum of 136.7 m. The average distance to the nearest breeding pond was 245.6 m, and this distance could be up to 777 m. The common spadefoot avoided shrubby areas, preferring forest litter (especially forest edges) and corn fields for its daily burrows. These results highlight the importance of protecting a wide range of habitats for this sedentary species with a predominantly terrestrial lifestyle.