Osteocephalus taurinus Steindachner 1862

Barrio-Amorós, César L. & Brewer-Carías, Charles, 2010, Venezuelan Guayana, with the description of five new species, Zootaxa 1942, pp. 1-68 : 33-34

Osteocephalus taurinus Steindachner 1862

Common casque-headed frog, Rana de casco común, Ko-maka

Locality VI. 23 March 2002. EBRG 4660–61 (adult males) .

This species is widespread in southern Venezuelan lowlands and uplands, where it breeds in ponds, lakes and streams in primary and secondary rainforest ( Donnelly and Myers 1991; Duellman 1978; Lescure and Marty 2000; Trueb and Duellman 1971). Two males were on the bank of a stream, about 8 m apart from each other, on the southern slope of Sarisariñama. Trueb and Duellman (1971) stated that this species is wary and escapes quickly, but our specimens were captured without difficulty. A female of this species was collected inside Sima Mayor, and its presence there was unexpected. In Sima Mayor there is no standing water other than that contained in bromeliads. We never observed other O. taurinus in bromeliads there nor in other places, although many other Osteocephalus are known to inhabit and reproduce in bromeliads ( Jungfer and Schiesari 1995; Jungfer et al. 2000; Faivovich et al. 2005). This species is often encountered in bushes and trees at night in the middle of the forest, especially adult females, both in Venezuela and Peru (CLBA, unpubl. data). The unexpected discovery of a female of this species inside Sima Mayor, and the fact that we never heard males calling there, suggests an accidental presence. It is likely that certain lowland species capable of climbing into crevices, such as O. taurinus or Norops ortonii , may find and follow one of the subterranean water channels that undermine the entire massif ( Brewer-Carías 1983). A search for a water source during the dry season may provide sufficient incentive for such a journey, and it may lead a few of these animals to unusual habitats, such as Sima Mayor.

This species is eaten by the Ye’kwanas. We have no data about how this species is prepared in this area, but we have observed the Yanomamo people at the Padamo River in the upper Orinoco gathering a similarlysized species, Trachycephalus venulosus , by stringing up hundreds of live frogs on a single liana.