koala

Koala (Phascolarctos cinereus) is a medium-sized marsupial native to eastern and southern Australia. Often called a koala bear in popular usage, it is not a bear; it belongs to its own family and is adapted to a largely arboreal, folivorous lifestyle.

Koalas are found in coastal and near-coastal forests and woodlands, where they rely on a network of eucalyptus trees. They occupy areas with suitable tree density and age structure, and their distribution is patchy and closely tied to the availability of preferred eucalyptus species. Each individual maintains a relatively small home range, with males typically defending larger territories than females.

Diet and physiology: Koalas feed almost exclusively on eucalyptus leaves, which are low in nutrients and high in fiber and toxins. They chew leaves and rely on specialized gut fermentation to extract nutrients slowly. Most of their water comes from the leaves, so they drink little; during droughts they may drink from water sources.

Behavior and reproduction: Koalas are mainly nocturnal or crepuscular and spend a large portion of the day resting in forks of trees, often up to 18–22 hours. They are solitary animals, with individuals maintaining overlapping but distinct ranges. Mating occurs primarily in the warmer months; gestation is about 35 days, after which the underdeveloped joey climbs into the pouch and remains attached to a teat for about six months, later riding on the mother’s back until it becomes independent.

Conservation: The koala is listed as Vulnerable on the IUCN Red List. Major threats include habitat loss from land clearing and wildfires, disease such as Chlamydia, climate change, and vehicle collisions. Conservation efforts focus on habitat protection, disease management, and rescue and rehabilitation programs.