Frog Daddy Barfs Out Babies


I've written about babies and barf here before, as well as odd gender-role switches in the animal world, but this story is even odder than those.  There's a small frog species called Darwin's frog (Rhinoderma darwinii) that is native to wooded streams of Argentina and Chile.  When it comes to mating, like most other frog species, Darwin's frogs engage in external fertilization, where the female releases her eggs into a standing body of water while the male simultaneously coats them in his sperm, resulting in fertilized eggs and eventually tiny, gill-breathing tapoles. 

But instead of leaving those tadpoles to fend for themselves until they grow limbs and lungs and leave the water, the Darwin's frog has developed a completely different approach to help its young survive.

Darwins Frog io9
Darwin's frogs have a rather odd and unique way of protecting their young from predators.

Male Darwin's frogs engage in a behavior called mouth-brooding, where they take their own fertilized eggs into their mouth just before they hatch.  They're not eating them.  Instead they store them in the vocal sacs that they otherwise use to make mating calls to attract females.  There the tadpoles hatch and develop in complete safety from fish, dragonfly larvae and all the other aquatic predators that normally threaten them (unless of course daddy gets eaten himself), surviving on the nutrients of the yolk that their mother's egg provided them.

When the tadpoles fully complete metamorphosis inside their father's vocal sac, he opens his mouth and "barfs" them out into the world, miniature versions of himself ready to fend for themselves. 

Watch this video to see the tadpoles writhing underneath the skin of these daddy frogs just before they reach full development and he barfs them out to begin life on their own.  You can't help but watch this and be fascinated at how odd and wonderful the natural world is!



And just for fun, here's a tongue-in-cheek video about the bizarre-brooding behavior of this particular frog.


Learn how to attract frogs to your own backyard habitat.

Photo and story inspiration via iO9.

David Mizejewski is a naturalist with the National Wildlife Federation. His goal is to inspire others to appreciate the wonders of nature. Meet David >







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