We describe a new species of Hyla from southern Ecuador that is diagnosed by the absence of an omosternum; the presence of an enlarged, curved, and pointed prepollex in males; features of coloration; and an associated suite of presumed anti-predator behaviors. Upon capture, frogs exuded a white, sticky fluid; continued perturbation elicited a defensive posture in which white patches on the posterior sides of the limbs and the vent were displayed. The phylogenetic relationships of H. tapichalaca with respect to the H. armata, H. larinopygion, and H. pulchella groups are discussed.
Key words: Antipredator behavior; Anura; Ecuador; Hyla armata group; Hyla larinopygion group; Hyla pulchella group; Hyla tapichalaca; New species
Etymology.- The specific epithet is an indeclinable word based on the name of the protected forest where all known specimens were collected. Reserva Biologica Tapichalaca is owned by Fundacion Jocotoco and was created to protect the habitat of rare birds, including the Jocotoco Antpitta, Grallaria ridgelyi (Krabbe et al., 1999), which is known only from this region.
Distribution and ecology.- Hyla tapichalaca is known only from the type locality, a small cascading stream in Montane Cloud Forest (Valencia et al., 1999) in the Nudo de Sabanilla. Annual mean precipitation in this region is 1000-2000 mm and annual mean temperature is 12-18 C (Cafiadas-Cruz, 1983).
The geographic distribution of H. tapichalaca is between that the H. Iarinopygion group (Colombia and Ecuador), H. armata group (central Peru to central Bolivia), and Andean members of the H. pulchella group (central Peru to central Argentina) (Duellman et al., 1997). Despite their relatively large size and striking color patterns, species in these groups are not commonly encountered, in part, because their calls are barely audible over stream noise (Duellman and Hillis, 1990). Indeed, all species in the H. larinopygion group (sensu Duellman and Hillis, 1990; Duellman et al., 1997) have become known in the last 30 yr (Duellman, 1973). Given that H. armata is phylogenetically nested within the H. larinopygion group (Duellman et al., 1997; Paredes-Recalde, 1999), it seems likely that focused efforts might reveal additional species of related frogs in the Andes of northern and central Peru.
"...If scars are correlated with the antipredator posture, then the behavior described for H. tapichalaca might also be exhibited by other species of the H. larinopygion and H. pulchella groups."
KIZIRIAN, D.; COLOMA, L.A. & PAREDES-RECALDE, A. 2003. A new treefrog (Hylidae: Hyla) from Southern Ecuador and a description of its antipredator behavior. Herpetologica. 59:339-349.