Nearly 3 billion koalas, kangaroos and other native Australian animals were killed or displaced by bushfires in 2019 and 2020, a study by the World Wide Fund for Nature (WWF) said on Tuesday, triple the group’s earlier estimates.

Some 143 million mammals, 2.46 billion reptiles, 180 million birds and 51 million frogs were impacted by the country’s worst bushfires in decades, the WWF said.

When the fires were still blazing, the WWF estimated the number of affected animals at 1.25 billion. The fires destroyed more than 11 million hectares (37 million acres) across the Australian southeast, equal to about half the area of the United Kingdom.

“This ranks as one of the worst wildlife disasters in modern history,” said WWF-Australia Chief Executive Officer Dermot O’Gorman in a statement.

The project leader Lily Van Eeden, from the University of Sydney, said the research was the first continent-wide analysis of animals impacted by the bushfires, and “other nations can build upon this research to improve understanding of bushfire impacts everywhere”.

The total number included animals which were displaced because of destroyed habitats and now faced lack of food and shelter.