The devastating wildfires sweeping across Australia could force some of the country’s best-loved animals to the brink of extinction, scientists warn.

Almost half a billion creatures are estimated to have died in blazes that have now engulfed 12 million acres – an area nearly two thirds the size of the island of Ireland.

And the crisis shows no sign of abating. The Penrith suburb of Sydney was the hottest place on Earth yesterday as temperatures soared to 48.9C (120F). Elsewhere in New South Wales, 80mph winds fanned the flames, with thousands of people fleeing their homes to take shelter on beaches.

The Victoria coastline pictured engulfed in flames and plumes of smoke yesterday as the government steps up efforts to control the rampaging fires

Flames have engulfed 12 million acres - nearly two thirds of the land area of Ireland, as wildfires have rampaged across the island of Ireland. These flames were by Lake Conjola last month

The Queensland silver-headed antechinus, already listed as endangered (left), may be wiped out by the blaze along with the Australian bittern (right) which has had its home in the Macquarie Marshes devastated

On Kangaroo Island, a wildlife paradise in southern Australia, two people and hundreds of koalas are feared dead. The human death toll stands at 23 since the fires began in September, and more than 1,500 homes have been destroyed.

Wildlife experts estimate at least 8,000 koalas have perished, almost a third of the entire population in New South Wales. Ecologists say the animals may disappear from some regions and have to be reclassified as an endangered species.

On a beach at Bastion Point in Victoria, where thousands of people were taken by boat, locals reported seeing hundreds of dead birds on the sand, including kookaburras.

Scientists fear that the destruction of nesting grounds and forests could have long-term implications for the populations of many species of birds.

Another creature under threat is the potoroo, a hare-size wallaby – its habitat in New South Wales’s Ngunya Jargoon forest has been destroyed.

Koalas may be wiped out from parts of Australia. A dehydrated one is pictured being given water at Port Macquarie Koala Hospital in New South Wales

The hip pocket frog, which lives in New South Wales rainforests, may also vanish

A Kangaroo is pictured being doused by a watering can as it attempts to cool down in New South Wales

There is also mounting concern for the endangered Australasian bittern, a large heron, due to the widespread destruction of the Macquarie Marshes, a wetland in north-western New South Wales.

The state has declared a week-long state of emergency, with tens of thousands told to evacuate coastal areas.

The potoroo may also be endagenered. Its home in the Ngunya Jargoon forest has been ravaged by fire

In the north-eastern state of Queensland, experts said the silver-headed antechinus, an endangered marsupial carnivore, was threatened with extinction.

New South Wales transport minister Andrew Constance compared the blazes to an ‘atomic bomb’. ‘It’s indescribable the hell it’s caused.’

Australian prime minister Scott Morrison announced an extra 3,000 defence force reservists were being drafted in to fight the fires. Meanwhile, there are fears that several large blazes could coalesce to form firestorms. ‘There are fires that are coming together that are creating fire-generated thunderstorms,’ said New South Wales Fire Service Commissioner Shane Fitzsimmons.