Natural history of Rhinella inopina Vaz-Silva, Valdujo & Pombal, 2012 (Anura: Bufonidae) in caves of the Brazilian Cerrado

Rhinella inopina is an inland species of the Rhinella crucifer group distributed throughout the Brazilian Cerrado, for which natural history information remains scarce, particularly regarding its use of subterranean environments. Here, we provide detailed observations on the ecology, behavior, and release call of R. inopina based on records from limestone caves in Terra Ronca State Park, northeastern Goiás, Brazil. Specimens were recorded and collected in the photic and twilight zones of two caves during the dry season, at distances of up to 39 m from the entrances, occupying both terrestrial and vertical rocky substrates. One male emitted a release call in response to manual stimulation simulating amplexus, accompanied by body inflation and tremors. The release call is characterized by a short call duration, a high number of extremely brief notes, and a dominant frequency similar to that of R. crucifer, though with a markedly faster temporal structure. Thanatosis was observed in multiple individuals during handling. Our findings expand the known behavioral repertoire of the species and suggests potential use of karstic and subterranean microhabitats, suggesting that caves function as important climatic refuges for R. inopina in the seasonally dry environments of the Cerrado.