Final answer:
Koalas are marsupials, not bears, and are native to Australia where they live a tree-dwelling lifestyle, mostly nocturnal and feeding on eucalyptus leaves.
Step-by-step explanation:
Koalas, often mistakenly referred to as "koala bears," are not bears at all; they are marsupials, a unique group of mammals known for carrying their young in a pouch. Unlike bears, which are placental mammals, koala joeys are born in a very immature state and must crawl into their mother's pouch to continue their development, relying on her milk for nourishment. Marsupials are distinct from monotremes, another group of mammals that lay eggs, and include other species like kangaroos, wallabies, and Tasmanian Devils.
These native Australian animals are known for their tree-dwelling lifestyle, feeding primarily on eucalyptus leaves, and usually exhibiting nocturnal or crepuscular activity patterns. The historic isolation of Australia has allowed the evolution of diverse wildlife, with koalas being a prime example of the continent's unique biodiversity. Their specialized diet and lifestyle reflect adaptation to their environment.