Darwin's Frogs, Rhinoderma darwinii, were discovered by Charles Darwin on his famous Beagle voyage. Both species of Darwin's Frogs employ a unique reproductive behavior. Males brood their developing tadpoles inside of their vocal sacs. Female Darwin's frogs deposit eggs on the damp forest floor of the temperate rainforests of Chile and Argentina. Males fertilize the eggs and remain nearby. Right before or just after the eggs hatch, the male takes the eggs or tadpoles into his mouth and manipulates them through a hole below his tongue and into his vocal sac. They will remain there and pass all the way through development and into small frogs in Rhinoderma darwinii. When the babies are ready to live on their won, the male literally coughs up fully developed miniatures of the adults. Rhinoderma rufum coughs up late stage tadpoles into pools of water. These frogs are endangered. R. rufum has not been observed in over 30 years. Rhinoderma darwinii's range has declined owing to emergent infectious disease and habitat loss.