Koala, Alert, Eastern Victoria, Australia

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Contrary to the popular name "koala bear", koalas (Phascolarctos cinereus) are not bears. They are a marsupial herbivore native to Australia, and the only representative of the family Phascolarctidae that still exists. Koalas are found in coastal regions of eastern and southern Australia, and inland in regions with enough moisture to support suitable woodlands. Koalas are not found in Tasmania or Western Australia.

Koala populations are in serious decline from the effects of habitat destruction and fragmentation, domestic dog attacks, and road accidents, in addition to the increased frequency and intensity of drought and bush fires due to climate change. There are estimates that between 63,665 and 38,648 remain in the wild. Without further measures to protect koalas and their habitat they could be extinct by 2050. In some regions up to 80% of the koala population was lost in the 2019 - 2020 bushfire season alone.

These typically sleepy and slow moving animals can leap more than six feet horizontally to nearby trees and live entirely on eucalypt leaves. Koalas also obtain most of their water from the leaves, but will sometimes drink water from streams. They sleep between 18 and 20 hours per day due to their very low-energy diet.

When temperatures rise above approximately 26 ºC (80 ºF), koalas increase the evaporative cooling in their airways by increasing their respiration rates. They simultaneously compensate for the extra water loss by decreasing the amount of water in their urine. Unlike bears, koalas do not have an insulating layer of fat below their skin. In colder temperatures koalas will curl their bodies into a ball when sleeping to reduce heat loss. At temperatures below about 10 ºC (50 ºF) koalas will sometimes shiver to produce extra body heat.