Why Do Koalas Only Eat Eucalypt Leaves? (English Version)
Having dissected a few Koalas and being familiar with their
gastrointestinal (GI) tracts I considered that if they ate anything more
fermentable than eucalypt leaves (i.e. Grass, fruit etc.) then the gases
produced from fermentation would remain immobile as they would not be able to
overcome the backpressure created by the size of their enormous GI tract and
its contents. This would cause extreme bloating and pressure incompatible with
long-term survival.
Warning - contains picture of koala guts