Feel like you've been pregnant forever? Don't worry, these mommy animals have a much tougher time.
The average lioness is pregnant for around 110 days. She usually gives birth to a litter of 1 to 4 cubs in a secluded den. She will often hunt by herself while the cubs are still helpless.
Giraffe pregnancies last between 400 and 460 days. The mother gives birth standing up and the embryonic sack usually bursts when the baby falls to the ground. Newborn giraffes are about 1.8m tall.
Killer whales are pregnant for 18 months. Mothers usually give birth to one calf about once every 5 years. Birth can occur at any time of year, although winter is the most popular.
Elephants are pregnant for 22 months, the longest of any land animal. A baby elephant can weigh up to 120 kgs at birth and can live for 70 years.
Koala's are pregnant for just 35 days. Twins are very rare and the world's first confirmed identical twin koalas, named Euca and Lyptus, were born at the University of Queensland in April 1999.
Wolf pregnancies lasts between 62 and 75 days, with pups usually being born in summer. The average litter consists of 5 to 6 pups. The pups are born blind and deaf and weigh around 500grams at birth.