Animals which today live in very different ecosystems and continents. The drastic and extreme climatic difference we have today did not exist before the flood. When God created the animals, he instilled in them an ability to adapt. God foresaw the entrance of sin and its effect on His perfect world. God created His creatures with an incredible ability to survive in various climates.
Some tropical animals can survive in cooler climates.
And some animals that now live in Polar Regions can also survive in warmer temperatures. Today marsupials live mainly in Australia. Penguins live in the Southern Hemisphere, while polar bears live in the north. Kangaroos did not have to hop all the way from Australia to get on the ark. Today kangaroos only live in Australia.