Darwin's frogs (Rhinoderma darwinii and Rhinoderma rufum) are the only known frog species in which the male rears the tadpoles in his vocal sac. Both species inhabit the native forest of central and southern Chile, while R. darwinii is also found in an area of the Argentine Andes.

Recently, these species have experienced alarming population declines. R. rufum was last recorded in 1981 and is currently classified as "Critically Endangered (Possibly Extinct)" by the International Union for Conservation of Nature (IUCN).

R. darwinii, on the other hand, still survives in the wild, but is classified as "Endangered" under Chilean law and by the IUCN, and as "Threatened" under Argentine law.