Does the koala eat anything other than eucalyptus?
17143#16
Koalas are herbivorous, and while most of their diet consists of eucalypt leaves, they can be found in trees of other genera, such as "Acacia", "Allocasuarina", "Callitris", "Leptospermum", and "Melaleuca". They are able to digest the toxins present in eucalyptus leaves due to their production of cytochrome P450, which breaks down these poisons in the liver. Though the foliage of over 600 species of "Eucalyptus" is available, the koala shows a strong preference for around 30. They tend to choose species that have a high protein content and low proportions of fibre and lignin. The most favoured species are "Eucalyptus microcorys", "E. tereticornis", and "E. camaldulensis", which, on average, make up more than 20% of their diet. Despite its reputation as a fussy eater, the koala is more generalist than some other marsupial species, such as the greater glider. Since eucalypt leaves have a high water content, the koala does not need to drink often; its daily water turnover rate ranges from 71 to 91 ml/kg of body weight. Although females can meet their water requirements from eating leaves, larger males require additional water found on the ground or in tree hollows. When feeding, a koala holds onto a branch with hindpaws and one forepaw while the other forepaw grasps foliage. Small koalas can move close to the end of a branch, but larger ones stay near the thicker bases. Koalas consume up to of leaves a day, spread over four to six feeding sessions. Despite their adaptations to a low-energy lifestyle, they have meagre fat reserves and need to feed often.
Koala
2671359#6
The grey gum regenerates by regrowing from the base and branches after bushfire. Trees live for over a hundred years. The grey-headed flying fox ("Pteropus poliocephalus") eats the flowers, while the leaves form a staple of the diet of the koala ("Phascolarctos cinereus"). Leaves in winter contain less nitrogen than those in summer, which the koalas make up for by eating more in winter months. The brown-headed honeyeater ("Melithreptus brevirostris") and yellow-tufted honeyeater ("Lichenostomus melanops") have been observed eating gum exudate from the stems. 
Fieldwork at several sites around central New South Wales showed that the red wattlebird ("Anthochaera carunculata") and noisy friarbird ("Philemon corniculatus") preferred to forage on the foliage of the grey gum over other trees, with the former appearing to oust the latter if both species were present.
Eucalyptus punctata
17143#13
Unlike kangaroos and eucalyptus-eating possums, koalas are hindgut fermenters, and their digestive retention can last for up to 100 hours in the wild, or up to 200 hours in captivity. This is made possible by the extraordinary length of their caecum— long and in diameter—the largest proportionally of any animal. Koalas can select which food particles to retain for longer fermentation and which to pass through. Large particles typically pass through more quickly, as they would take more time to digest. While the hindgut is proportionally larger in the koala than in other herbivores, only 10% of the animal's energy is obtained from fermentation. Since the koala gains a low amount of energy from its diet, its metabolic rate is half that of a typical mammal, although this can vary between seasons and sexes. The koala conserves water by passing relatively dry faecal pellets high in undigested fibre, and by storing water in the caecum.
Koala
2202364#2
"Stankervision" also features some cartoons, but in "Stankervision" style. One regular such cartoon is about the adventures of "Inebriated the Koala", which was created by Waco O'Guin in 1993 and is introduced as "everyone's favorite eucalyptus-eating marsupial", to which the koala replies "Eucalyptus? You can lick THIS!" as he points to his crotch.
Stankervision
12276202#9
A long-lived tree, "Eucalyptus robusta" can live for at least two hundred years. Trees regenerate by regrowing from epicormic buds on the trunk after bushfire. The grey-headed flying fox ("Pteropus poliocephalus") eats the flowers, and the koala ("Phascalarctos cinereus") eats the leaves. "Eucalyptus robusta" appears to be one of several key species of eucalypt for the koala in the Shire of Noosa in Queensland. The musk lorikeet feeds on the nectar of the blossoms. It is a keystone species on the New South Wales Central Coast and Illawarra regions, where it is one of few reliable winter-flowering plants. Stands of "E. robusta" have been drastically reduced by land clearance. Some remnant trees in Robson Park in the Sydney suburb of Haberfield are the last vestiges of the Sydney Coastal Estuary Swamp Forest Complex community in Sydney's inner western suburbs.
Eucalyptus robusta
7994902#5
"Eucalyptus saligna" regenerates by regrowing from epicormic buds on the trunk and lower branches after bushfire. Trees live for over two hundred years. The grey-headed flying fox ("Pteropus poliocephalus") eats the flowers, the koala ("Phascalarctos cinereus") eats the leaves, and crimson rosella ("Platycercus elegans") eats the seed. The longhorn beetle species "Paroplites australis", "Agrianome spinicollis" and "Tessaromma undatum" have been recorded from the Sydney blue gum.
Eucalyptus saligna
49871#29
An essential oil extracted from eucalyptus leaves contains compounds that are powerful natural disinfectants and can be toxic in large quantities. Several marsupial herbivores, notably koalas and some possums, are relatively tolerant of it. The close correlation of these oils with other more potent toxins called formylated phloroglucinol compounds (euglobals, macrocarpals and sideroxylonals) allows koalas and other marsupial species to make food choices based on the smell of the leaves. For koalas, these compounds are the most important factor in leaf choice.
Eucalyptus
3175680#1
Omnivores are usually generalists. Herbivores are often specialists, but those that eat a variety of plants may be considered generalists. A well-known example of a specialist animal is the koala, which subsists almost entirely on eucalyptus leaves. The raccoon is a generalist because it has a natural range that includes most of North and Central America, and it is omnivorous, eating berries, insects, butterflies (Hackberry Emperor, for example), eggs and small animals. Monophagous organisms feed exclusively, or nearly so, on a single other species.
Generalist and specialist species
3901711#1
The giant koala was an arboreal marsupial weighing about 13 kg, a little more than modern koalas. It is the largest known tree dwelling marsupial ever to have lived. Scientists say there is a clear similarity between the physical appearance of "P. stirtoni" and the modern koala. It is assumed that the giant koala was a folivore which was specialised to feed on eucalyptus leaves, like its extant relative.
Giant koala
26964177#1
Blue-leaved stringybark is a koala food tree. A field study conducted in the Campbelltown district southwest of Sydney published in 2000 found that koalas preferred Blue-leaved Stringybark and Grey Gum but only when the two tree species were growing on shale-based rather than sandstone soils. Stringybarks are some of the most difficult of all eucalyptus plants to identify. However, the bluish colour of the leaves makes this species fairly easy to identify.
Eucalyptus agglomerata