Why no fauna

[GunksFoy]

I find it strange that the only critters are the ones we kill for exp. there are no regular fauna such as Birds large cities, forests, plains mountains and deserts but no sparrows,bluebirds etc, is this hard to do?

In the starting areas there is a plethora of non-aggressive fauna. And I'm pretty sure there are birds and stuff flying around in the sky in some places. Imo, it doesn't add much to the game to have them.