The large-billed tern uses its disproportionately long and thick beak to catch fish — either by plunge-diving into the water or skimming the surface with its beak as it flies. It has a commensal relationship with the tucuxi river dolphin, which often flushes fish towards the surface while hunting.

The Titicaca water frog lives solely in the depths of Lake Titicaca in the Andes mountains at elevations of 3,810 metres (12,500 feet). Its copious skin folds allow it to breathe — through cutaneous respiration (skin breathing) — at such high altitudes, its lungs are only 1/3 the size they should be.

The Amazon milk frog isn't named for its milky white appearance, instead, its name refers to a poisonous milky substance that it secretes when threatened. It also uses the fluid as "sunscreen" — lathering it over its body to prevent itself from drying out in the sun.