Through their livelihoods based on slash and burn agriculture, fishing and hunting, they have both shaped the local ecological system and sheltered it from destruction.

UNESCO: EDUCATION

Though foxes are of recent introduction in Australia (having been brought for sport by British settlers), many marsupial predators, now extinct, were present before the arrival of man in both his Aboriginal and his European forms, so the ecological system of plants, herbivores and carnivores in the eucalyptus forests would probably not have been that different in the evolutionary past.

ECONOMIST: Ecology raids the techniques of chemistry

"You basically have two ecological universes - a system with dingoes and a system without dingoes - they are completely different places, " Dr Letnic told BBC News.

BBC: Dingoes 'could help rare species'

And a back-of-the-envelope calculation based on the 1.8m sorts of organism recognised so far as species under the Linnaean system, on the rate at which new species are being discovered and on such ecological matters as the average number of parasites (themselves new species) that each free-living species harbours, suggests the final total may be around 30m.

ECONOMIST: Biodiversity