I think the koala thing is an herbivore being an opportunist for food. I witness on campus last month some of the many many ground squirrels there eating something off the road. When I looked to see what it was, it was a member of their colony that got ran over by a car, AND THEY WERE EATING IT!! Someone walked by and they ran off AND ONE HAD A PIECE OF MEAT IN ITS MOUTH! A SQUIRREL!!! Bottom line: if nut eaters can somehow eat meat that they find, so can eucalyptus eaters. Well, then again maybe they were eating the nuts from its stomach, but who knows. Cats have been known to eat rabbit stomachs to feed on grass that way, but that makes sense with them being predators.