Jumping between narrow banks: social spacing of the stream-dwelling montane frog, Crossodactylus trachystomus (Hylodidae)

Abstract

Spacing patterns among individuals can reveal many ecological and behavioral features, such as responses to resource availability and social organization. The study of the amphibian movements still constitutes a gap in the knowledge of the animal ecology, and the general issues of the patterns of home range are poorly known to date. Herein, we evaluated the social spacing of a small stream-dwelling frog (Crossodactylus trachystomus), an endemic species from the Espinhaço mountain range in southeastern Brazil. We found that C. trachystomus shows one of the smallest home ranges among anurans, indicating a high philopatry level. We also showed that the home range size did not differ between females and males, neither was influenced by individual body size, which reveals a possible limitation for the use of larger home ranges in riparian systems. The distribution of home ranges showed high overlap among adult males, suggesting a weak territorial behavior or a possible “dear enemy effect” for this species. Beyond expanding the knowledge about the spatial ecology and behavior of the genus Crossodactylus, our outcomes contributed to the understanding of space use and the social organization of frogs, revealing spatial patterns that can be expected for other stream-dwelling frog species.