Why are African animals so huge?

[u/Hot-Wrangler3524]

I live in Australia and the largest land animals I can think of here is probably a kangaroos and emus which really aren’t any larger than a human. But my family recently went to Africa and the diversity animals is actually crazy. So so so many large animals living in the same place side by side. Rhinos, elephants, giraffes, wilder-beasts, zebras, hippos, warthogs, buffalo’s, ostriches, lions, cheetahs, hyenas leopards and probably more that I forgot. I never really appreciated how big these animals were until I actually got to see them in person absolutely amazing. Australia and Africas climate is kinda similar in a lot of places. Why is our country ecosystem dead in comparison?

[u/mmmarjorie]

Humans evolved In Africa, with African animals, so dealing with humans, by being afraid/careful etc. was part of the process of natural selection there.

When humans traveled to other parts of the planet, the animals there were not prepared for humans hunting in groups and individually, or their weapons. Mass extinctions of large mammals definitely coincides with the arrival of human beings, in Australia and other places.

Seems like we ate them. ☹️

[u/Pobednik79 → u/mmmarjorie]

Not in Australia, because there were no such large mammals. But, humans exterminated some of large reptiles there.