At least 3 billion animals were killed or displaced during Australia’s devastating bushfires of the past year.
Mammals, reptiles, birds and frogs died in the flames or from loss of habitat.
The findings meant it was one of “worst wildlife disasters in modern history”, said the World Wide Fund for Nature (WWF), which commissioned the report.
Mega blazes swept across every Australian state last summer, scorching bush and killing at least 33 people.
During the peak of the crisis in January, scientists had estimated that 1.25 billion animals had been killed in New South Wales and Victoria alone.
But the new estimate takes in a larger area. About 11.46 million hectares – an area comparable to England – was scorched from September to February.
In February, the Australian government identified 113 animal species which needed “urgent help” after the bushfires.
Almost all on the list had lost at least 30% of their habitat in temperate forests and grasslands of Australia’s south and east.
Koalas and wallabies – as well as bird, fish and frog species – were among those needing the most help.
The government has pledged US$35 million to wildlife and habitat recovery, but environmentalists have called on Australia to strengthen its conservation laws.
Australia is holding a royal commission inquiry into the fires, which is due to report findings in October.