Originally posted by Uluru Australian bush is another story, and 300mm+TC you use is perhaps about right, because the bush is broken up, trees and treetops are broken up, and animals hear and smell from a mile someone's approaching because of the ever present wind.
If stuck in an European forest, 300mm is often way too long. 200mm and under is better, because forests are much denser.
Don't take it bad Uluru, but...
If every wildlife shooter is using 300mm+ lenses, there a very good reason. Give us an unlimited budget, we'll probably all choose a 500mm+ lenses to use in hides, plus a lighter option to use when walking (150-450, 150-600, 300 f4, 70-300). The farther is your subject, the higher are the chances that it will show you a natural behavior, and the better will be your pictures.
Most important factors when choosing the focal length is not the environment, but rather the mistrust and size of your subjects. In Australia (where I've been for 3 months, but I'm from France), most animals have very little to no mistrust, but still, go taking a good fairy-wren picture with a 85/135mm and share it with us, that will be quite interesting
. But yes, you can shoot a dingo on Fraser Island with a 85mm, or even a 24mm, but that's not a representative example of what wildlife photography is.
For a lot of us (well, at least in France, where animals mistrust is huge :'( ), this is wildlife photography: