Dogs, Wolves, and Dingos......

Maybe the theory is that, since dingos came from domestic dogs (I do think that is the right order), they are already not "natural", but were tampered with by humans? There's also a much smaller distribution of dingos throughout the world (only found in one relative small part of the world) whereas wolves are so much more varied. I mean, if you said that kangaroos and koalas are the natural diet of dingos (yeah, I'm assuming not, but that's the extent of my knowledge about the fauna of Australia ), so therefore it should be the natural diet of all dogs, well, it isn't going to work so well in the rest of the world.

I'd also expect that, again due to both distribution and the status of wolves as the more natural species, there has simply been a lot more study of them.

Between 1971 and 1976, 160 stomachs of dingo [Canis dingo] were collected from rangeland of Western Australia, with conditions ranging from those of arid Nullarbor to tropical Kimberley. There were 14 empty stomachs. In the other stomachs, mammals were the main food by percentage of number and volume. The main mammal foods were macropods, mainly red kangaroo (Megaleia rufa) and euro (Macropus robustus), which together were over 70% by volume of food and occurred in over 65% of stomachs. There were small amounts of domestic sheep, cattle or goats and some food had been eaten as carrion, probably including one sheep that had been shot. Birds provided small volume but were found in 15% of stomachs; the main bird was emu (Dromaius novaehollandiae). Small mammals, reptiles and insects were found and grasshoppers or locusts may be an important food during plagues of those insects. Where rabbits occurred they were a large part of the diet and dingo population may fluctuate in response to changes in rabbit population. Dingos seemed to be opportunistic feeders and to prefer wild animals to domestic stock even though those were usually equally available.