Mouth-brooding frog
Mouth-brooding frogs, also known as Darwin's frogs, are unique amphibians belonging to the family Rhinodermatidae, primarily found in southern Chile and Argentina. Male mouth-brooding frogs exhibit a fascinating reproductive behavior by carrying their young in their vocal sacs until the tadpoles are ready to survive independently. These frogs generally have slender bodies that reach about one inch in length, with adaptations allowing them to jump effectively. All species of mouth-brooding frogs are currently listed as endangered or critically endangered, highlighting their vulnerable status in the wild.
These cold-blooded, terrestrial frogs typically thrive near forest streams and have a distinct, high-pitched whistle for communication. The reproductive process begins with females laying clutches of 20 to 30 eggs on land, which males subsequently gather and roll into their vocal sacs. Following a period of development, the young hatch and remain in the male's vocal sac until they metamorphose into froglets and can hop out on their own. Mouth-brooding frogs primarily feed on insects and have a lifespan of around 11 years, reaching reproductive maturity at about six years. Understanding their unique biology and conservation status provides insight into the challenges faced by these remarkable creatures.
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Mouth-brooding frog
Mouth-brooding frogs carry their litters, or broods, of young in their mouths, particularly in the males' vocal sacs. When the frogs are old enough to survive on their own, they hop out of their fathers' mouths. These frogs are also called Darwin's frogs or mouth-breeding frogs.
Kingdom: Animalia
Phylum: Chordata
Class: Amphibia
Order: Anura
Family: Rhinodermatidae
Genus: Various (see below)
Species: Various (see below)
All frogs in the two genera of mouth-brooding frogs are endangered or critically endangered. They have green or brown skin on their backs and paler skin on their bellies. Their slender bodies generally grow to be about one inch (three centimeters) long. Like other frogs, their hind limbs are longer than their front limbs. Since their hind limbs are bent under their bodies, mouth-brooding frogs can spring and jump from place to place. These frogs are called mouth-brooding frogs because the males carry the litters, or broods, of young frogs in their mouths until the tadpoles or froglets are ready to survive on their own. The males carry them in their vocal sacs along the bottom of their mouths. Like other amphibians, mouth-brooding frogs are cold-blooded. This means their body temperatures are the same as the temperature of their surroundings.
Mouth-brooding frogs are terrestrial, or ground-dwelling. They live near forest streams in southern Chile and southern Argentina, depending on the species. Mouth-brooding frogs have a distinct, high-pitched whistle for their call.
Like other frogs and toads, mouth-brooding frogs are carnivorous, or meat-eating. They survive mostly on a diet of insects.
Female mouth-brooding frogs lay clutches, or batches, of between 20 and 30 eggs on land. Male mouth-brooding frogs gather around these clutches and wait. After about 10 to 20 days the eggs begin to twitch as if the young are about to hatch. At this point, the males gather 5 to 15 eggs with their tongues and roll them into their vocal sacs. Their vocal sacs are enlarged and ready to hold these young frogs, and their presence does not interfere with the males' eating. Once inside the vocal sacs, the young hatch from the eggs. In the Rhinoderma rufum species, the male carries the eggs to the water and deposits them. The tadpoles swim and change, or metamorphose, into adult frogs from there. In Darwin's frogs, the father carries these tadpoles around in his vocal sac until they are froglets. When they can survive on their own, they hop out of the male frog's mouth. They reach reproductive age after six years.
The lifespan for mouth-brooding frogs is around 11 years.
Species include:
Barrio's frog Insuetophrynus acarpicus
Chile Darwin's frog or Northern Darwin's frog Rhinoderma rufum
Darwin’s frog or Southern Darwin's frog Rhinoderma darwinii
Bibliography
"Barrio's Frog." The International Union for Conservation of Nature and Natural Resources (IUCN) Red List of Threatened Species, www.iucnredlist.org/species/10832/79809262. Accessed 1 May 2024.
"Northern Darwin's Frog." The International Union for Conservation of Nature and Natural Resources (IUCN) Red List of Threatened Species, www.iucnredlist.org/species/19514/79809567. Accessed 1 May 2024.
"Southern Darwin's Frog." The International Union for Conservation of Nature and Natural Resources (IUCN) Red List of Threatened Species, www.iucnredlist.org/species/19513/79809372. Accessed 1 May 2024.