Just a note about the Kangaroos and Koalas in Australia
A male kangaroo is called a boomer
A female kangaroo is called a flyer
A baby kangaroo is called a joey
When European explorers first saw these strange hopping animals they asked a native Australian (aborigine) what they were called.
He replied "kangaroo" meaning "I don't understand" your question.
The explorers thought this was the animal's name, and that's how the kangaroo got its name. From Koala Express
The koala is everyone’s favorite, but be aware – it’s not a bear. You can spot koalas all along Australia’s temperate eastern coast.