Animal Parenting Extremes

Animal Parenting: Animal parenting runs from total neglect to heroic sacrifice. Some species abandon eggs at laying, others fast for months, carry young in their mouths or even let offspring eat them. Evolutionary biologists explain the variety through trade offs between producing many young cheaply and investing heavily in a few.

Emperor Penguin: Males incubate a single egg on their feet through the Antarctic winter, fasting for roughly two months while huddling in groups that rotate so everyone gets a turn in the warm center. Females return from the sea with food just as the chick hatches.

Seahorse: Male seahorses carry the young, receiving eggs into a brood pouch where they are fertilized and nourished. In some species a single birth can release up to around 2,000 tiny fry.

Surinam Toad: The female presses fertilized eggs into the spongy skin of her back, which grows over them. The young develop entirely inside the pockets and emerge as fully formed toadlets, skipping the free swimming tadpole stage.

Gastric Brooding Frog: This Australian species, discovered in 1973, swallowed her fertilized eggs, shut down her stomach acid and brooded tadpoles in her stomach before giving birth through her mouth. The frog vanished within about a decade of its discovery, taking the trick with it.

Common Cuckoo: The female lays an egg in another bird's nest, and the newly hatched chick shoves the host's eggs overboard. Its begging call can mimic a whole brood of hungry chicks, tricking foster parents into feeding it nonstop.

Nile Crocodile: Mothers guard nests for around three months, then gently crack the eggs and carry hatchlings to the water in their mouths. The same jaws that can crush bone become a nursery.

Lake Malawi Cichlids: Many species are mouthbrooders, with females holding eggs and then fry in their mouths and going without food for weeks. Fry dart back into her mouth at the first sign of danger.

Graneledone boreopacifica: In 2014, researchers at the Monterey Bay Aquarium Research Institute reported a female deep sea octopus guarding her eggs for four and a half years, the longest known brooding of any animal. She did not eat during that time and died soon after the eggs hatched.

Burying Beetle: A pair finds a small dead animal, strips it, rolls it into a ball and buries it as a nursery. Both parents then feed their larvae regurgitated food and may cull the brood to match the food supply.

Sand Tiger Shark: Pups begin life by eating their siblings in the womb, a behavior called intrauterine cannibalism. The strongest embryo in each of the mother's two uteri devours the others, so only two pups are born.

Stegodyphus lineatus: Mother spiders of this species feed their spiderlings regurgitated food, then finally let them eat her in an act called matriphagy. Her body becomes the last meal for her brood.

Boulengerula taitana: This Kenyan caecilian, a limbless amphibian, grows a special fatty outer layer of skin that her babies scrape off and eat with specialized teeth. They gain weight fast during their first weeks.

Discus Fish: Parents secrete a nutritious mucus from their skin that their fry feed on for the first weeks of life, a kind of fish milk. Both parents take turns nursing.

Greater Flamingo: Both sexes produce crop milk, a red tinged liquid rich in fat and protein, to feed their single chick. Parents can fade in color as they pour pigments into the milk.

Malleefowl: Males build a mound of sand and rotting vegetation and spend months checking its temperature with their beaks, adding or removing material to hold it near 33 degrees Celsius. Chicks hatch alone and dig out with no parental care.

Granny (J2): Estimated to have lived to around 105, this orca matriarch led her Southern Resident pod for decades. Research on resident orcas shows older females who have stopped reproducing boost the survival of their adult sons, one of the rare examples of menopause in animals.

Red Kangaroo: A mother can pause the development of an embryo until conditions improve, and she can suckle a newborn in the pouch and an older joey at her side at once, producing two different milks from different teats.

African Lion: When new males take over a pride they often kill young cubs, which brings the females into heat sooner so the newcomers can sire their own litters. Mothers fight back, sometimes hiding cubs away from the pride.

Wattled Jacana: Females hold large territories and mate with several males, then leave the males to incubate and raise the chicks. Fathers can carry chicks tucked under their wings, with tiny legs dangling out.

Cuckoo Catfish: Synodontis multipunctatus lays eggs among the mouthbrooding cichlids of Lake Tanganyika. The cichlid mother scoops them up with her own, and the catfish hatch first and eat her young from inside her mouth.

Orangutan: Mothers nurse for six to eight years and keep a young one close for even longer, giving them among the longest childhoods of any non human animal. They may have just one baby every eight or nine years.

Wolf Spider: Mothers drag their egg sac attached to their spinnerets, then carry the hatched spiderlings on their back for a week or more. The babies cluster on her abdomen like a living blanket.

Strawberry Poison Dart Frog: Mothers carry tadpoles one at a time to water trapped in bromeliad leaves. She then returns repeatedly to lay unfertilized eggs as food for each tadpole.

Great Hornbill: The female walls herself inside a tree cavity with mud, leaving a narrow slit, while the male ferries food through it for weeks. She molts her feathers while sealed in, then breaks out with the chick.