Other Common Names
Wanderer, Milkweed

They can show up anywhere, just about any time. I've seen more of them in late Autumn than at other times (ie April/May), but that might be because I've been looking for them at that time. Usually I don't see them in great numbers, except at Mount Annan Botanic garden, where I've seen a lot of them, and they breed like rabbits on the milkweeds (if the number of caterpillars is anything to go by).
I've found a couple of problems in trying to get photos of this species. Firstly, they're wary buggers. I find it very difficult to get close to them. The slightest noise and they're off. I did find one or two which were very preoccupied feeding from bottlebrushes, and that's where the other problem comes in....... these things are too big! If I'm close enough to focus on them, then it tends to be too close to get more than half the butterfly in the frame.