Nick Hawkins / Fitzinger's rainfrog (Craugastor fitzingeri) photographed on white. Tortuguero National Park, Costa Rica, November.

Jen Guyton / Robber frog (Craugastor sp.) photographed in studio at Cruces Biological Station, Costa Rica.

Jen Guyton / Robber frog (Craugastor sp.) photographed in studio at Cruces Biological Station, Costa Rica.

Jen Guyton / Robber frog (Craugastor sp.) photographed in studio at Cruces Biological Station, Costa Rica.

Jen Guyton / Robber frog (Craugastor sp.) photographed in studio at Cruces Biological Station, Costa Rica.

Jen Guyton / Robber frog (Craugastor sp.) photographed in studio at Cruces Biological Station, Costa Rica.

Jen Guyton / Robber frog (Craugastor sp.) displays incredible camouflage (crypsis) at Las Cruces Biological Station, Costa Rica.

Alex Hyde / Slim-fingered rainfrog (Craugastor crassidigitus) Central Caribbean foothills, Costa Rica.

MYN / JP Lawrence / Frog (Craugastor polyptychus) Escudo de Veraguas, Panama Meetyourneighbours.net project

MYN / JP Lawrence / Craugastor polyptychus Escudo de Veraguas, Panama. Meetyourneighbours.net project

MYN / JP Lawrence / Unidentified leaf litter frog (possibly Craugastor megacephalus) Bastimentos, Panama. Meetyourneighbours.net project

MYN / JP Lawrence / Northern rain frog (Craugastor ranoides) Escudo de Veraguas, Panama. Meetyourneighbours.net project. Critically endangered species.

Joel Sartore / Photo Ark / Common rain frog (Craugastor fitzingeri) portrait, from the wild, Tapir Valley, Costa Rica.

Joel Sartore / Photo Ark / Bransford's litter frog (Craugastor bransfordii) carrying juvenile on back, from the wild, Tapir Valley, Costa Rica.

Joel Sartore / Photo Ark / Bransford's litter frog (Craugastor bransfordii) portrait, from the wild, Tapir Valley, Costa Rica.

Joel Sartore / Photo Ark / Isla Bonita robber frog (Craugastor crassidigitus) portrait, from the wild, La Libia, Costa Rica.

Joel Sartore / Photo Ark / Isla Bonita robber frog (Craugastor crassidigitus) portrait, from the wild, La Libia, Costa Rica.

Joel Sartore / Photo Ark / Isla Bonita robber frog (Craugastor crassidigitus) portrait, from the wild, La Libia, Costa Rica.

Joel Sartore / Photo Ark / Pacific litter frog (Craugastor stejnegerianus) portrait, from the wild, La Libia, Costa Rica.

Joel Sartore / Photo Ark / Fitzinger's robber frog (Craugastor fitzingeri) portrait, Natura Eco Park, Costa Rica. Captive.

Joel Sartore / Photo Ark / Fitzinger's robber frog (Craugastor fitzingeri) portrait, Natura Eco Park, Costa Rica. Captive.

Roman Willi / Rugose robber frog (Craugastor rugosus) portrait, Osa Peninsula, Costa Rica.

Joel Sartore / Photo Ark / Common rain frog (Craugastor fitzingeri) seated, breathing, Tapir Valley Nature Reserve, Bijagua, Costa Rica. Controlled conditions.

Joel Sartore / Photo Ark / Tabasaran robber frog (Craugastor tabasarae) close up of male and female, El Valle Amphibian Conservation Center. Captive.

Joel Sartore / Photo Ark / Tabasaran robber frog (Craugastor tabasarae) male and female profile, El Valle Amphibian Conservation Center. Captive.

Joel Sartore / Photo Ark / Two Bob's robber frogs (Craugastor punctariolus) resting before one jumps off, Gamboa Amphibian Rescue and Conservation Project. Captive.

Joel Sartore / Photo Ark / Bob's robber frog (Craugastor punctariolus) close up of head, Gamboa Amphibian Rescue and Conservation Project. Captive.

Claudio Contreras / Common Leaf-litter Frog (Craugastor loki), Finca Arroyo Negro, El Triunfo Biosphere Reserve, Chiapas, southern Mexico, April

Claudio Contreras / Common leaf-litter frog (Craugastor loki), Finca Arroyo Negro, El Triunfo Biosphere Reserve, Chiapas, southern Mexico, April

Claudio Contreras / Robber Frog (Craugastor sp.), Finca Arroyo Negro, El Triunfo Biosphere Reserve, Chiapas, southern Mexico, April