In New South Wales, the worst affected, it has been estimated that between 480-800 million animals have burned.

"These are vertebrate animals, primarily mammals, reptiles and birds," says Olle Forshed, forest expert at the World Wildlife Fund (WWF) in Sweden.

But if you look at the whole country, Professor Chris Dickman at the University of Sydney has calculated the number to as many as 1.25 billion animals that died in the fires. And it does not include insects.

The highest death rate in the world

Australia is already the country with the highest extinction rate of mammals in the world. Many of their animal species are also endemic, that is, they exist only in Australia, making them extra sensitive.

But has any species completely disappeared in the flames yet? Olle Forshed points out small marsupials, rat kangaroos and cockatoos as some species that are at risk.

- It's hard to say exactly. But around 10 species have been severely affected and are at risk of being completely extinct, says Olle Forshed.

See more in the clip above.