Koalas are marsupial mammals that only live in certain parts of Australia, specifically the southern and eastern coastal regions but not Tasmania or Western Australia. They eat eucalyptus leaves exclusively, consuming around 1 pound per day by chewing the leaves into a fine slurry and swallowing it. Koalas have sharp claws that help them climb trees, and males are generally larger than females, weighing up to 14 kg compared to 5 kg for northern females. They are mostly solitary and silent but males make loud cries during mating season.