Koalas are known to be very picky eaters. Koalas are folivores, meaning they are herbivores that specialize in eating leaves, and in this case, they primarily eat eucalyptus. Eucalyptus, one of the largest flowering trees, contain very potent chemicals as a defense against predators. Eucalyptus oil is steam distilled eucalyptus leaves, commonly used as an antiseptic, industrial solvent and the active ingredient in many insect repellents.

 

Koalas sleep twenty-two hours a day, only to wake up and eat more eucalyptus. One reason koalas sleep this much is because the toxins in eucalyptus take an intense toll metabolically, leading to their metabolism being most active during states of rest, as previously discussed. Koalas are partial to different species of eucalyptus, already a problem in itself, deforestation has exacerbated this issue. A large portion of their digestion comes from a delicately balanced gut biome, containing main components to optimize the breakdown of the leaf. Koala gut bacteria is highly specialized, with the ability to breakdown only eucalypt toxins from species previously introduced. Koalas will almost never introduce themselves to new eucalyptus because their bodies simply cannot tolerate those new toxins.

 

Koalas are a highly territorial species, with an alpha male taking charge of areas that are approximately 0.5 Km. Relocating koalas in Australia is more complicated because there is over 700 different species of eucalyptus, meaning that if a koala is taken to a new area, the possibility that that koala has the correct gut biome to break down those leaves is astronomically small. The diversification of their gut biome naturally would be impossible and adjusting to a new area could be a fatal mistake. 

 

It has recently been discovered that in order to diversify a koala's biome, it is possible to implant bacteria from collected feces of one group of koalas, turn them into an edible concentrated pellet, and feed them to a different group of koalas. The preliminary results of this technique shows that any koala can eat any species of eucalyptus if they have the necessary bacteria to remove the specific toxins from any given eucalyptus leaf. Urbanization and deforestation is not slowing down so perhaps the advancement in bacterial diversification of koalas gut biome will help save these picky eaters.