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Parental Care in Amphibians
Christina Miller

Last update: Friday, March 9, 2007.

Reproduction is the only instinct any animal has that puts the survival of the species ahead of the success of the individual. You might not expect amphibians to be good moms and dads, but parental care amongst anurans, caudates and caecilians is quite common. Frogs show the greatest diversity in how they care for their offspring, and about ten percent of frog species demonstrate parental care. About a quarter of all caudates (with members from all families) will carry out some type of parental care, and all egg-laying caecilians (about half of the known species) are suspected to guard their eggs. There is remarkable diversity in how amphibians will care for their young. They have the largest variety of parenting skills of all vertebrates, some basic and some bizarre.

Parental care varies greatly from species to species. The defining characteristic of this behaviour is that one or both parents are increasing the survival rate of their eggs or offspring in some way that is potentially costly to themselves. The parents may be increasing their own risk of being eaten, they may eat less, or they may reduce the number of clutches they can produce in a season because of the increased amount of time devoted to fewer groups of offspring. The more intense the parental care, the fewer offspring are produced.

“Babysitting”

Amphibian eggs lack the tough shells and protective inner membranes found in amniotes, making them vulnerable to predators and the environment. The simplest form of caring for your young would be to guard the eggs to help prevent desiccation and predation. This is seen in many species, and while it is often the female that does the protecting, there is a surprising amount of amphibian fathers that guard their eggs.

In many frogs and the giant salamanders (Cryptobranchidae), females will travel through male territories to find a mate, and once the eggs are laid the male will guard them. Some males will guard more than one clutch from several different females. The male African bullfrog, Pyxicephalus adspersus, is well-known for violently guarding his eggs and tadpoles, and even digging trenches to other water bodies so that his tadpoles may escape being dried up. These trenches can be quite impressive, sometimes exceeding 15 m (48 ft).

The incredible dart frogs

Poison dart frogs of the genus Dendrobates exhibit remarkable parenting skills. The most famous is the strawberry poison dart frog (D. pumilio) , that will lay a small clutch of three to five eggs in a gelatinous mass, which is visited by either parent periodically to ensure their viability. The male or female will step on the mass when the tadpoles are ready to hatch, and the larva will wiggle and stick to an adhesive mucous on the parent's back. The parent will carry the tadpole to a hidden body of water, often the axils of bromeliads, and deposit the tadpole into the pool. Each tadpole has its own pool of water, and the female returns every 1-8 days to inspect the pool and lay trophic eggs for the tadpole to eat. She will keep doing this for the three weeks it takes for the tadpoles to develop into froglets.

Astonishingly, the Madagascan climbing mantella (Mantella laevigata), has evolved a very similar method of parental care on a completely different continent as the South American dart frogs. The male leads the female to a water-filled well during courtship, where a single egg is laid. Males defend the tadpole-bearing wells, and females return to lay a trophic egg.

Swallowing the eggs

Several species of frog will swallow fertilized eggs for the duration of their incubation, then regurgitate or disgorge the tadpoles or froglets. The male Darwin 's frog (Rhinoderma darwinii) of South America will keep eggs in his vocal sac until they develop into froglets. Even more amazing is the Australian gastric brooding frog (Rheobatrachus silius), which is unfortunately now extinct. The female will swallow up to twenty eggs and keep them in her stomach for development. She will not eat while she is holding eggs, and an increase in prostaglandin that is secreted by developing tadpoles will shut down gastric juice production and muscle movements of the stomach.

“What lovely skin, Mommy!” “The better to feed you with, my dears!”

Caecilians, including Boulengerula taitanus, will allow their newborn young to feed off the fatty outer layer of skin. The offspring are born with a set of teeth to gnaw off the nutrient-rich tissue from the mother. It is unknown how the babies know when to stop eating so that they do not injure the parent. It is thought that this method may be more efficient than producing yolks for the offspring to live off of once born, possibly because in the incidence of a dead neonate, no yolk will have been wasted on it.


Amphibians are definitely successful by adapting to taking care of their young. There appears to be a relationship between a terrestrial lifestyle and parental care, possibly because on land the chances of survival for young are greater if the parents put some effort into it. There are certainly aquatic species that take care of their young, but these behaviours are more common amongst land-dwelling amphibians.

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