Plectrohyla avia

Plectrohyla avia is the largest member of the genus Plectrohyla, with males reaching about 90 mm (3.5 in) and females about 70 mm (2.8 in) snout–vent length.[4] It was described by Laurence Cooper Stuart in 1952 based on a single specimen. This specimen—the holotype—is an adult male that measured 86 mm (3.4 in) SVL. The tympanum is small but very distinct. There is a heavy supratympanic fold that merges with the fold-like canthus (or in less technical terms, "lateral skin folds"[4]). The fingers have vestigial webbing whereas the toes are moderately webbed. The prepollex ("spikethumb") is simple and horny. Vocal slits are absent.[2] The teeth of the upper maxilla are long and protruding.[4]

Based on an observation from Chiapas, breeding takes place underwater and involves axillar amplexus. Male advertisement call is a brief and rapid trill. Males were observed calling underwater and from within small holes and crevices in the splash-zone of waterfalls.[4]

Natural habitats of Plectrohyla avia are cloud forests at elevations of 1,700–2,200 m (5,600–7,200 ft) above sea level. It typically occurs in vegetation along mountain streams.[1] Reproduction has been observed just at the start of the rainy season in a small pool.[4] The well-developed lateral skin folds might facilitate dermal respiration.[4]

It is an uncommon to rare species that is threatened by habitat loss (deforestation and transformation of forest to agricultural areas) as well as chytridiomycosis.[1] It might be, however, more common and widespread than currently thought, but with only a short period of activity at the beginning of the rainy season.[4]

• Plectrohyla avia in breeding amplexus, Volcan Tacaná, Chiapas, Mexico on YouTube