European Plethodontid Salamanders on the Forest Floor: Testing for Age-Class Segregation and Habitat Selection

Spatial distribution of animals is affected by environmental and social factors, acting both at inter- and intraspecific levels, and generating patterns of segregation or aggregation. Several studies investigated age-class segregation of the European Cave Salamander Speleomantes strinatii, in underground environments, showing a clear spatial segregation. We investigated the spatial distribution of S. strinatii on the forest floor, on 111 plots surveyed three times/season for two consecutive seasons, in northern Italy during autumn 2017 and spring 2018. We analyzed count data to model co-abundance of adults and juveniles, using a conditional two-species N-mixture model, incorporating environmental covariates. In contrast with what was observed in underground environments, we recorded no spatial segregation between juvenile and adult of S. strinatii on the forest floor. Instead, we found that adults and juveniles showed different responses to environmental features.