Originally published 2020-01-05.
In early January 2020, as Australia's Black Summer fires were still burning, University of Sydney ecologist Professor Chris Dickman estimated that about 480 million mammals, birds and reptiles had been affected by the fires in New South Wales alone since September 2019. Reports at the time also said around 8,000 koalas may have died on the state's mid-north coast. Those were early, deliberately conservative estimates, not a count of bodies. When the season was over, a continent-wide study put the number of animals killed or displaced at nearly 3 billion, including more than 60,000 koalas.
Where the 480 million figure came from
The number spread around the world within days, often rounded to "half a billion animals dead". The University of Sydney issued a statement on 3 January 2020 to explain its basis. Dickman had co-authored a 2007 report for WWF on the impact of land clearing on wildlife in New South Wales. That study estimated how many mammals, birds and reptiles typically live in each hectare of different habitats, using field surveys from the state and similar regions.
Multiplying those densities by the area burned gave the 480 million figure. It excluded insects, bats and frogs entirely, and the university stressed that the original densities were chosen to be cautious, so the real loss was likely higher. On 8 January Dickman raised the estimate to more than 800 million animals in New South Wales and over a billion nationally.
The word "affected" matters. Some animals died in the flames; others survived the fire front but later starved, were caught by predators in open burned ground, or lost the tree hollows they need. The method could not separate these outcomes, which is why researchers spoke of animals affected rather than confirmed deaths.
Rural Fire Service volunteers free a koala from fallen branches during the fires. Image shared on Facebook.
Koalas on the mid-north coast
Koalas were especially exposed. They move slowly, live high in eucalyptus trees whose oily leaves burn fiercely, and tend to climb upwards rather than run when fire arrives. On 27 December 2019, federal environment minister Sussan Ley told ABC radio that up to 30 per cent of the koalas on the New South Wales mid-north coast may have been killed, roughly matching the share of their habitat that had burned. The estimate of about 8,000 koalas lost in that region circulated widely in the same days.
Ley said she was working with koala specialists on habitat corridors and on plans for releasing animals once they had recovered in hospitals, backed by several million dollars of federal funding. The region around Port Macquarie, about 390 kilometres north of Sydney, was one of the hardest hit, with large fires in prime koala country such as Lake Innes.
The Port Macquarie Koala Hospital
The Koala Hospital in Port Macquarie became the public face of the rescue effort. Staff and volunteers spent the Christmas period caring for dozens of burned and dehydrated koalas, treating singed paws and fur, giving fluids and bandaging burns. Its online fundraiser, originally set up to pay for drinking stations for wild koalas, drew donations from all over the world; by early January 2020 media reported more than two million Australian dollars raised, an extraordinary sum for a small charity.
Above: an injured koala is given water by syringe during treatment. Below: a kangaroo in a burning landscape in New South Wales. Images as published by CNBC.
Rescue work came with a lesson that wildlife carers repeated often: if you find an injured animal, wrap it loosely in a towel or blanket, keep it cool and quiet, offer a little water if it can drink, and call a licensed wildlife rescue group or vet rather than trying to treat it yourself.
A koala with burnt fur recovering at a treatment centre. Image as published by CBS News.
The human toll and the political storm
People suffered heavily too. In mid-December 2019, two volunteer firefighters died near Sydney when a falling tree struck their tanker and it rolled. By the end of the season 33 people had died directly in the fires and a later analysis linked hundreds more deaths to bushfire smoke. Around 24 million hectares burned across the country and more than 3,000 buildings, including about 2,800 homes, were destroyed. Fires reached World Heritage areas, including the Greater Blue Mountains and parts of the ancient Gondwana Rainforests.
Prime Minister Scott Morrison faced fierce criticism for taking a family holiday in Hawaii in December 2019 while the crisis deepened; he cut the trip short and later apologised. Social media users revived the old tourism slogan "Where the bloody hell are you?" as a protest hashtag. Cartoonists were merciless, as this Australian Financial Review cartoon by Peter Nicholson shows:
Scomo hulas while Australia burns. My cartoon in the Fin @FinancialReview this morning. pic.twitter.com/rHXxF34c9r
— Peter Nicholson (@NiCartoons) December 17, 2019
Drought, heat and climate
The fires followed years of drought across eastern Australia and the country's hottest and driest year on record in 2019. A strong positive Indian Ocean Dipole kept rain away from the south-east. Lightning started many of the biggest blazes, along with accidents and a smaller number of deliberately lit fires; claims at the time that arson was the main cause were not supported by the fire agencies' data.
Scientists have long warned that a warming climate lengthens fire seasons and makes extreme fire weather more frequent in Australia. That fed an intense debate about the government's climate policy, Australia's reliance on coal for electricity and exports, and its stance at international climate talks such as the COP25 summit in Madrid in December 2019. Farmers, meanwhile, were already reeling from the drought before the fires destroyed fences, stock and pasture.
The final count: nearly 3 billion animals
In July 2020, a study commissioned by WWF-Australia and led by Dr Lily van Eeden of the University of Sydney, with Dickman among the scientists, covered the whole burned area for the first time. It estimated that about 3 billion animals had been killed or displaced: some 2.46 billion reptiles, 181 million birds, 143 million mammals and 51 million frogs. WWF-Australia's chief executive called it one of the worst wildlife disasters in modern history.
A follow-up report in December 2020 put the koala figure at more than 60,000 killed, injured or affected nationally: over 41,000 on Kangaroo Island in South Australia, more than 11,000 in Victoria, nearly 8,000 in New South Wales and around 900 in Queensland. Koalas in Queensland, New South Wales and the ACT were later listed as endangered in 2022.
The scientists were frank about the limits. They had little data for some species, and the estimates still did not include insects or other invertebrates. What the numbers really describe is the scale of the habitat loss and the pressure on species that were already declining.
In record heat Australia and South Australia, where temperature have risen to 40 degrees, koalas approached cyclists on the road to seek water. pic.twitter.com/DvW84gbaRq
— Akki (@akkitwts) December 28, 2019
(This post is no longer available on X.)
How to read big wildlife numbers
- Check the area. The 480 million figure covered New South Wales; the 3 billion figure covered the whole continent.
- Check the wording. "Affected" or "displaced" is not the same as "killed".
- Check the date. Estimates made while fires are still burning are almost always revised.
- Check what is missing. Insects, frogs and bats were left out of the early estimate entirely.
Read that way, the early numbers were not exaggerations. They were a first, cautious attempt to measure something that turned out to be even larger.
Sources: University of Sydney: statement on the 480 million estimate (January 2020); ABC AM, 27 December 2019: Sussan Ley interview; CNBC, 3 January 2020; Al Jazeera, July 2020: Nearly 3 billion animals killed or displaced; University of Sydney, December 2020: 60,000 koalas impacted; Wikipedia: 2019–20 Australian bushfire season. Cartoon: Peter Nicholson, Australian Financial Review.
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