Why did tigers and rhinos never make it to Australia?

[Deleted]

They made it to Sumatra, they made it to Java, but they never made it to Australia. Orangutans also made it from Sumatra to Borneo but not Australia. But saltwater crocodiles and pythons managed to get from Indonesia to Australia.

[Deleted]

I know next to nothing about Australia, and did little research before writing this... but my guess is that pythons may have arrived in the region accidentally via cargo ships and the like and just managed to adapt and survive.

For the big saltie, Crocodylus porosus, being salt-tolerant as the name implies, could cross short oceanic barriers, which possibly could've helped it to island hop.

So why no tigers? Well, the most likely possiblity is a lack of suitable prey. There are not a lot of large animals in Australia to begin with, and what few exist (namely kangaroos) are very hard to bring down. There used to be actual megafauna there, and large predators to go with them, but they died out after humans arrived on the continent (around 65,000 years ago). So if any tigers ever tried to come over from Asia, they probably couldn’t establish a foothold on the continent — first because of the local competition, and then because of the lack of food.

For rhinos? I have no idea. Maybe the environment and climate was just ill-suitable for them.

[Deleted]

Jan 5, 2023 16:52:26 GMT @ling said:

I know next to nothing about Australia, and did little research before writing this... but my guess is that pythons may have arrived in the region accidentally via cargo ships and the like and just managed to adapt and survive.

For the big saltie, Crocodylus porosus, being salt-tolerant as the name implies, could cross short oceanic barriers, which possibly could've it to island hop.

So why are no tigers? Well, the most likely possiblity is a lack of suitable prey. There are not a lot of large animals in Australia to begin with, and what few exist (namely kangaroos) are very hard to bring down. There used to be actual megafauna there, and large predators to go with them, but they died out after humans arrived on the continent (around 65,000 years ago). So if any tigers ever tried to come over from Asia, they probably couldn’t establish a foothold on the continent — first because of the local competition, and then because of the lack of food.

For rhinos? I have no idea. Maybe the environment and climate was just ill-suitable for them.

Could’ve sworn you were Australian, lol. Interesting theories you have.

[Deleted]

Answer from Hardcastle requested.

[Hardcastle]

I'm in bed and should be sleeping because I have to work in a couple hours, but look up "Wallace's line". It's a faunal boundary between south east Asia and Australasia where the sea was too deep and vast for animals to cross. Reptiles and ants and ratite birds and etc pre-date the splitting of the continents, bats flew over the divide, and a rodent or two made the journey likely with the earliest human adventurers 60 000 years ago, but basically to the west of the divide we have placental mammals, and to the east marsupials and monotremes.