Hard to jump over the water!
THEY ARE FLIGHTLESS BIRDS.
Ned wants them all to himself. :P
If you lived in Australia with all those Aussie women would you ever leave?
'Roos are really bad at stowing away on ships
Australia is a continent in and of itself. It has the type fauna it has because of that and I do not know why they haven't spread elsewhere. That huge toad has taken over a lot of the area and it is gross. But, it was grown there by someone who brought it. The Dingo is not indigious to Australia, even though its history travels many, many years back.
Have you ever tried to swim an ocean? They're rooos, not whales.
We have wild wallabies in the Uk, maybe kangaroos were too big for the stupid feckers to carry back to their stately homes.
We don't let their kind live around us. Sounds familiar huh?
Australia has been a continent isolated from all others for millions of years. Species evolved there separate from all others. The origins of species there are distinct from all others due to their prolonged isolation and the nature of the animals that were kept in isolation, primarily the marsupials.
Horses, cows, pigs and sheep are not indigenous to the Americas either for the same reasons.
Kangaroo love Australia, just as much as Panda love China. Some animals are just more patriotic than others.
Umm because Australia is an Island, thousands of Kms from anywhere... Just a stab in the dark...