Jen Guyton / Nocturnal foam-nest frog (Chiromantis sp.) resting on a tree in Gorongosa National Park, Mozambique.

Jen Guyton / Nocturnal foam-nest frog (Chiromantis sp.) resting on a tree in Gorongosa National Park, Mozambique.

Yashpal Rathore / Malabar gliding frog (Rhacophorus malabaricus), pair in amplexus, building foam nest over water body. Coorg, Karnataka, India. Endemic to Western Ghats.

Yashpal Rathore / Malabar gliding frog (Rhacophorus malabaricus), pair in amplexus, building foam nest over water body. Coorg, Karnataka, India. Endemic to Western Ghats.

Adrian Davies / Wallace's flying frog ( Rhacophorus nigropalmatus) foam nest overhanging pond. Darnum Valley, Sabah, Borneo.

Adrian Davies / Red-sided keelback snake (Xenochrophis trianguligerus) predating foam nest of Wallace's flying tree frog (Rhacophorus nigropalmatus) Danum Valley, Sabah, Borneo.

Chris Mattison / Foam nest of Four-lined Tree Frog (Polypedates leucomystax) Danum Valley, Sabah, Borneo

Chris Mattison / Foam nest of Four-lined Tree Frog (Polypedates leucomystax) Danum Valley, Sabah, Borneo.

Staffan Widstrand / African Foamnest frog (Chiromantis rufescens), Hwange N P, Zimbabwe

Christian Ziegler / Red-eyed Tree Frog (Agalychnis callidryas) being consumed by Foam-nest Frog (Leptodactylus sp), Soberania National Park, Panama

Pete Oxford / Smokey Jungle Frog (Leptodactylus pentadactylus), Yasuni National Park, Amazon, Ecuador

Luciano Candisani / Crilloa Frog (Leptodactylus ocellatus) showing ear, Sao Paulo, Brazil