Polar Bear

Female polar bears must pile on 400 pounds during their pregnancy. This allows them to endure life in the maternity den, where the mother doesn’t eat and sleeps through the birth of her cubs. After leaving the den, she continues to nurse the cubs, providing them with fat-rich milk. It is only when they leave the den area and head towards the sea ice that the mother can start catching seals, after fasting for eight months. The cubs continue to stay with their mother for a further few years, learning how to hunt while staying protected from predators, including male polar bears.

Orangutan

Orangutans spend their lives high up in trees. In the first two years of a young orangutan’s life, contact with their mother is never broken. They are completely dependent on their mother for food and transportation—they cling to her stomach, sides and back while she moves through the trees and feed on her milk. They can be fed until they are 8 years old, the longest dependence of any animal. Even when they are too old to be fed and carried they still remain close to their mother, travelling with her, and eating and resting in the same trees until they are around 10 years old.

Elephant

Elephant mothers not only give birth to the biggest babies on Earth of around 250 pounds, they also endure a 22-month long pregnancy. Calves are initially born blind and dependent on their mothers, but fortunately are born into a matriarchal society. This means that all the females in the herd help to raise the calf. The baby’s aunts, grandmothers, sisters and cousins are known as 'alloparents' and when a predator is near, they gather together to surround and protect the calf.

Octopus

Between 50,000 and 200,000 eggs are laid by female octopus. Eggs take around 40 days to hatch, during which time the mother stays close to them, protecting them from predators and gently blowing currents of water over them to provide oxygen. She never leaves them and never eats. This brooding can be epic—up to 53 months—the longest of any animal, allowing the young to grow as large as possible. This means that when the eggs start hatching, the mother will be too weak to defend herself, and will die starving and exhausted.

Great Hornbill

In a tree cavity, two great hornbill eggs are laid, although only one usually hatches. With the female inside the nest and the male outside, the two parents work together to enclose the female and eggs inside using a combination of dung and food. A small slit is left, through which the male brings food for the female. Around a week before the chick is ready to leave the nest, the female breaks out to help her mate find food for their chick, but after she leaves, the chick helps rebuild the entrance. Both parents then take turns feeding the chick until it is ready to leave. The mother’s self-imposed isolation is an ideal way to keep herself and her young safe from predators.

Earwig

Earwigs are among the few non-social insects that show maternal care. Mother earwigs provide their eggs with warmth, protect them from predators and keep them clean to prevent the growth of fungus. The eggs hatch in around seven days, and the mother helps them break through their shells. She then continues to protect the nymphs and feeds them regurgitated food for another few months until they have moulted for a second time.

Wolf Spider

Wolf spiders are among the most caring mothers in the arachnid world. Most spiders hang their eggs in a web and then abandon them, but female wolf spiders actually wrap their eggs in silk to create an egg sac which they strap to their bodies and carry wherever they go. Once the eggs hatch she continues to take care of them, letting them ride on her back for several days. This allows them to stay safely camouflaged from predators until they are old enough to fend for themselves.

Caecilians

Caecilians look like worms but are actually amphibians, inhabiting wet tropical regions of South America, Africa and Southeast Asia. There are nearly 200 species of caecilians, most of which give birth to already-developed offspring. Before their birth, these young caecilians use their short, blunt scraping teeth to feed on the lining of their mother’s oviduct. Once they are born, they stay with their mother for several weeks, during which time the mother grows a thick outer layer of skin every three days that is rich in fat and other nutrients. The young use their special teeth to peel off her skin and eat it, a behaviour called dermatotrophy which is unique to this already unique group of animals.

Black Lace-Weaver Spider

The black lace-weaver spider mother goes one step further. This species is matriphagus, which means that the young devour their mother after hatching. Between 60 and 130 spiderlings feed on eggs laid by their mother to provide sustenance, but once they have eaten their brothers and sisters they eat their mother. She could flee the nest and avoid death, but instead stays and even encourages the spiderlings onto her body, making the ultimate sacrifice to give them the nutrition they need to grow.