Pete Oxford / Emerald Tree Boa (Corallus caninus) adult, Amazon, Ecuador

Gerry Ellis / Emerald Tree Boa (Corallus caninus) hanging on tree branch, Amazon, Peru

Michael & Patricia Fogden / Emerald Tree Boa (Corallus caninus) portrait in rainforest, South America

Pete Oxford / Boa Constrictor (Boa constrictor) coiled around a mossy tree branch in the rainforest, South America

Claus Meyer / Green Anaconda (Eunectes murinus) moving through wetland vegetation, Pantanal ecosystem, Brazil

Morley Read / Slow motion clip of a Garden tree boa (Corallus hortulanus) flicking its tongue, Amazon rainforest, Orellana Province, Ecuador. (non-ex)

Morley Read / Slow motion clip of a Garden tree boa (Corallus hortulanus) flicking its tongue, Amazon rainforest, Orellana Province, Ecuador. (non-ex)

Cyril Ruoso / Malagasy ground boa (Acrantophis madagascariensis) camouflaged in leaf litter. Anja Community Reserve, Madagascar.

Cyril Ruoso / Madagascar ground boa (Acrantophis madagascariensis) swallowing adult Ringed-tailed lemur (Lemur catta). Madagascar.

David Pattyn / Green Anaconda (Eunectes murinus) , Cuyabeno wildlife reserve, Sucumbios, Ecuador, July

David Pattyn / Green Anaconda (Eunectes murinus) , Cuyabeno wildlife reserve, Sucumbios, Ecuador, July

Cyril Ruoso / Malagasy Ground Boa (Acrantophis madagascariensis) swallowing Ring-tailed Lemur (Lemur catta) prey, Madagascar