Natural History of the Flattened Waterfall Frog Cycloramphus boraceiensis (Anura, Cycloramphidae)

Abstract

Cycloramphus boraceiensis is an endemic frog of the Atlantic Forest of southeastern Brazil. Although relatively easy to find and distributed over a well-sampled region in southeast Brazil, little is known about its natural history, breeding activity, and vocal repertoire. In the present study, we provide new information on pre-and post-hatching larval development, describe new traits of their advertisement calls, describe its aggressive call for the first time, and provide new data about adults’ and tadpoles’ defensive strategies. We found individuals on rocks on cascaded streams or within rocky crevices along streams inside forested habitats. Males concentrated their calling activity between 03:00 and 5:00 h and between 19:00 and 23:00 h. The aggressive call is shorter than the advertisement call and has greater variation in the number of pulses and emission rate. The eggs hatched at Gosner’s stage 25, after seven and eleven days of oviposition, and tadpoles took between eight and ten days to complete metamorphosis. This study contributes to the knowledge of the Flattened Waterfall Frog by filling natural history gaps that can be useful for species conservation and bringing attention to traits that still need further investigation, such as color plasticity and microhabitat selection.