Emperor Penguin
Successfully raising a chick is a truly remarkable accomplishment for this mom and dad. Courtship for a typical couple starts in March and April when temperatures in the Antarctic are around -40 degrees Fahrenheit. Emperor Penguins are also serial monogamists and will wait for their previous year's mate before breeding again. The female produces one egg and leaves it in the care of its father while she makes the nearly 74-mile journey back to sea to capture the fish that she will need for feeding. Upon returning to the nesting site, she must relocate her mate and chick. Then, the pair switches off caring for their offspring, while the other makes the same long journey to the ocean and back for food. Help out these amazing moms at The World Wildlife Fund
Harp Seal
As if raising a child on a moving sheet of ice patrolled by Polar Bears and fur poachers wasn't hard enough, the harp seal mom nurses her pup on 48% fat seal milk continuously for 12 days without eating. Her pup will gain an average of 5 lbs. per day during this 12-day nursing period, while mom herself will lose about 7 lbs. per day.
Koala Bear
Relying almost entirely on eucalyptus leaves for her diet, the Koala Bear mom rarely leaves the safety of her treetop home. The mom gives birth to a quarter-inch long joey, a hairless, blind, and earless version of herself. The joey stays in her unique pouch for about six months where it slowly grows from a diet of only her milk. After six months, the joey crawls out of the mother's pouch and takes up a place on to her back, where it will remain for another six months.
Meerkat
Meerkats live in packs of about 20, dominated by one mating pair that give birth to 2 to 5 pups in a litter, with up to four litters a year. In a group of meerkats with so many new pups, it is often the aunts and sisters of the group who care for the young. After 21 days underground, the pups emerge to join the foraging party, where they learn the skills needed to live in the Kalahari Desert.
Queen Bee
Living like a queen isn't necessarily true for the Queen Honey Bee. On a warm day, she will mate with 12-15 males, or drones. But mating this one time is enough to fertilize her eggs for 2-7 years. Once mated, the Queen will lay around 2,000 eggs a day during the springtime throughout her life.
Orangutan
The only exclusively Asian living genus of the great ape, the orangutan is considered "critically endangered" but with a reproduction cycle of about 6 to 7 years between offspring, repopulation has proved difficult. It does not help that orangutans reconstruct their homes of leaves and sticks every single day, meaning that a typical mom lives in about 30,000 new homes during her lifetime.
Polar Bear
A habitat where the average winter temperature can reach -40 degrees Fahrenheit isn't exactly ideal for raising young, so mother polar bears dig an underground den where they remain in a hibernation-like state through the coldest winter months. Mothers birth between November and February, to a litter that almost always consists of two cubs, who then live in the safety of the den while nursing on the fasting mother's milk. At the end of this period, the family emerges from the den and eventually makes their way to the moving sea ice, where the mother can catch seals once again. At this point the mother has been fasting for up to eight months, while raising two hungry cubs.
Seahorse
Talk about role reversal: Many of the functions performed by females in most species are handled by dad in seahorse couples. Mating takes place when the female seahorse deposits dozens to thousands of eggs inside the male's brood pouch, as the male releases a cloud of sperm to fertilize them. The eggs become enveloped in tissue and receive everything they need from dad including a hormone usually only seen in females. Mom remains relatively absent during this time and visits once a day, to re-secure the bond with the father.
African Elephant
The largest land mammal also has the longest pregnancy in mammals, averaging a staggering 22 months. Elephants usually give birth to one calf, who will rely on the mother's milk for around 4-6 years. One would think that years of devotion to her calf and the protection of the herd would lead to a healthy adult elephant, but in reality, very few calves live to adulthood.
Giant Pacific Octopus
A female Octopus has only one goal, to have one successful brood of eggs in her lifetime. A female octopus will lay around 200,000 eggs in her lair and defend them at any cost. During the one month of caring for her eggs the female is starved almost to death and may even ingest one of her own arms before she will leave her eggs for food. Once the eggs hatch, the offspring float around in blooms of plankton while their mother wanders out of her lair, too weak to defend herself, often falling prey to predators.