That is too say, does Dungeons & Dragons not draw heavily enough from the menagerie of animals that live in other parts of the world outside Europe, Canada and the United States?
No, I don't think so. A few points:
1) Europe and North America have
some common fauna, but also a lot of differences. I think it's a mistake to bundle the two of them together and then say that you've got a meaningful point. My campaign setting has a Pleistocene subglacial megafaunal base, for example, which is quite a bit different than a Medieval European one. Sure, both have wolves and bears and deer, for example, but when you come across an imperial mammoth, short-faced bear or saber-tooth, you know that you're not in a fantasy analog of jolly olde Englande anymore.
2) The folkloric and literary antecedants of the game are rooted in a quasi-Medieval European vein, therefore it's hardly surprising if the default fauna is quasi-European as well.
3) There's actually quite a bit more variety in terms of what is available in the rules for megafauna than you imply, at least in 3e with which I'm much more familiar than any other edition. I can do a reasonable job approximating the fauna--at least in terms of animals that would need stats--of most of the continents just with the SRD document alone.
4) Animals, lacking any magickal or supernatural abilities, generally, are easy to swap for one another if needed. For example, although there are stats in the SRD for both wolves and hyeanas, couldn't you use the stats for one as a good approximation for the other? Same for leapord and cougar, bison, aurochs and yak, deer and antelope, etc. The great diversity of life in the animal kingdom isn't really going to be meaningfully represented in game stats and still offer us any difference. I might well be justified in insisting that a South American scarlet macaw and a European raven are two very different animals, but for the life of me I can't figure out why they should have different
stats from each other. They're both among the most intelligent of birds, they have a tradition as serving as companions/familiars (for witches for ravens, for pirates as macaws), they both have a limited ability to mimic human speech (at least in literature, if not always reality) and they're about the same size, they have similar claws, their beaks aren't necessarily the same, but really is that going to make any different on the bite attack?
When I went to go stat out my Pleistocene subglacial megafaunal components, I found that with existing animals and a handful of dire animals, I didn't have
any gaps at all, and in fact, I was a bit spoiled for choice, because books like
Frostburn gave me needlessly divergent stats for a few creatures.
