For a start, the koalas is not a bear, but the polar bear is. The Word "bear" is not even part of the koala's name. Differences include:
- Koalas are marsupials, giving birth to undeveloped young which complete their development in the female koala's pouch. Polar bears give birth to live young which are fully developed.
- Baby koalas are called joeys, while baby polar bears are called cubs.
- Koalas are endemic to Australia alone. Polar bears are found in Arctic regions.
- Koalas are herbivorous, feeding only on eucalyptus leaves, flowers and bark. Polar bears are carnivorous, i.e. meat-eaters, feeding on live prey.
- Baby koalas drink mother's milk during their first 6-7 months of life. After 30 weeks, the mother produces a substance called pap. This substance is actually a specialised form of the mother's droppings which, having passed through her digestive system, give the joey the enzymes it needs to be able to start digesting the tough gum leaves, making an easier transition for the baby koala to start eating eucalyptus leaves. Polar bears make a simpler transition from mothers' milk to meat, and no such preparation is required.
- Koalas are essentially grey in colour, while polar bears are white.
- Koalas are arboreal, or tree-dwelling, while polar bears live on the ground.
- Koalas are much smaller than polar bears.
- Two of the koala's digits on their forelimbs act as opposable thumbs, enabling koalas to reach out and grasp the leaves they want. Polar bears do not have any such feature or capability with their paws.
