Australia has lost more mammal species than any other continent and has one of the worst rates of species decline among the world's richest countries, a five-yearly environmental report card released by the government has said.

Animals such as the blue-tailed skink are only known to exist anymore in captivity, while the central rock-rat and Christmas Island flying fox are among mammals considered most at risk of extinction in the next 20 years, largely due to introduced predator species, the report said on Tuesday.

The sandalwood tree is also in decline.

The report, which comes after drought, bushfires and floods ravaged Australia over the past five years, said increasing temperatures on land and sea, changing fire and rainfall patterns, rising sea levels and ocean acidification were all having significant impacts that would persist.

"The State of the Environment Report is a shocking document – it tells a story of crisis and decline in Australia's environment, and a decade of government inaction and willful ignorance," Environment Minister Tanya Plibersek said in a statement.

She said the previous government received the report in late 2021 and, in contrast, the new Labor government would make the environment a priority.

"I won't be putting my head in the sand," she said.

Opposition deputy leader and former environment minister Sussan Ley's office was not immediately available for comment.

'Black Summer' bushfires 

The number of species added to the list of threatened species or in a higher category of threat grew 8 percent from the previous report in 2016 and would rise sharply as a result of the bushfires that hit in 2019-2020.

The "Black Summer" bushfires killed or displaced an estimated 1 billion to 3 billion animals and razed 9 percent of koala habitat.