On January 7 WWF Australia published a statement saying it estimated that around 1,25 billion animals may have been killed directly or indirectly from fires that have burnt 8.4 million hectares across Australia.
That's the equivalent to the whole of country of Austria.
A statement by the University of Sydney published on January 3 estimated that 480 million animals had been affected in NSW alone since bushfires started in September 2019.
Both these numbers are based on a report written in 2007 by Prof Chris Dickman from The University of Sydney for the World Wide Fund for Nature (WWF) on the impact of land-clearing on Australian wildlife in New South Wales.
The report estimated that there was an average of 17.5 mammals, 20.7 birds and 129.5 reptiles per hectare (10,000 square metres). They've then multiplied that by the amount of land hit by the fires.
"We've estimated that in the three million hectares of New South Wales alone that were burned up until about 10 days ago probably as many as 480 million mammals, birds and reptiles would have been affected by the fires," Prof Dickman said earlier this month.
SBS Italian asked Lorenzo Crosta, Director of the Avian, Reptile and Exotic Pet Hospital at Sydney University how accurate these figures could be.
According to Dr. Crosta, this number could be actually higher or lower depending on a few factors.
“This figure does not include other systematic groups such as amphibians, insects and other types of arthropods or lower animals. In that case, the number could be much higher," he explained.
Furthermore, such figures refer to the number of animals estimated to be present in the area, and some would have managed to survive the fires, Dr. Crosta added.
Until the fires subside, the full extent of damage will remain unknown, WWF Australia warned.
The ability to escape
Some animals would have managed to escape, explained Dr. Crosta.
However the presence of human barriers such as fences would have stopped them and this also needs to be taken into account, he added.
“For example, imagine that some animals wanted to escape, but there were some barriers, built by humans, that stopped them as they tried to flee.
“This would have meant that they got caught in these fences; they would have not been able to run away from the fires and would have died on the spot”.
A dead kangaroo is seen on Kangaroo Island after the fires which have burned for several days, Monday, January 6, 2020. Source: AAP
Koalas among species most hit by fires
Some large animals, such as kangaroos, are faster than other small animals, or koalas, who are typically very slow, said Dr. Crosta.
“Koalas respond to bushfires in two ways: if they are on the ground they curl up on themselves hoping that the fire will go over them, therefore they are usually burnt on the back or shoulders. Others instead climb to the tops of the trees which in many cases do not burn and, if they are not killed by smoke, they survive in this way,” says Dr. Crosta.
So koalas are one of the species most hit by these fires, also because of other diseases that are hindering their ability to reproduce, explained Dr. Crosta.
"Koalas have been significantly reduced in numbers. We have discovered in recent years that they are prey to at least two rather serious infectious diseases including two variants of a viral form and two variants of a rather dangerous bacterial form which also limit the ability of the animals to reproduce.
"So if we put the loss of the environment together with the loss of vitality, with the numerical decline of the species in general and then add the devastation brought by the fires, we seriously run the risk that the number of koalas falls below an extremely dangerous number," added Dr. Crosta.
In November last year news outlets reported claims from the Australian Koala Foundation that the marsupial was “functionally extinct.”
Functionally extinct means that a koala living today has a joey and that joey doesn’t go on to have another joey.
Dr Valentina Mella, a koala conservationist in the School of Life and Environmental Sciences, said back then that the claims could be dangerous to conservation efforts.
“The term 'functionally extinct' refers to species whose reduced populations are no longer viable,” said Dr Mella.
“While I understand that the motive is to emphasise the threats to koalas, the implication of declaring koalas as functionally extinct is that there is no value in koala conservation. This can have dangerous consequences. Focus should be shifted to the valuable research-based management strategies that can be applied to enhance koala conservation, which could address the threats that have recently been highlighted," Dr Mella said.
And even after the fires, several experts warn it would be wrong to declare the species "functionally extinct".
Lake Innes Nature Reserve Paul in the ICU recovering from burns at The Port Macquarie Koala Hospital on November 29, 2019 in Port Macquarie, Australia. Source: Getty Images AsiaPac
Can wildlife come back to what it was before the fires?
Dr. Crosta says under normal circumstances an ecosystem can recover completely after a bushfire. However, these bushfires may represent an anomalous situation.
"Now there are two aspects: one, there is a biological law that says that if the environment 'X' can bear a number 'Y' of animals of a certain species, these will be there. So once the plants have rebuilt, the animals should return to more or less the numbers granted by the availability of plants that provide food," said Dr. Crosta.
However, it's possible that these fires may have killed too many animals, going over a tipping point.
"So the problem is: first, can the plants actually regenerate and secondly, how far we have come with the death rate of the animals? There is a limit beyond which if a population is devastated, it is no longer able to recover also because genetic diversity has become too low. In this case, I am referring specifically to koalas".
Dr Lorenzo Crosta with a saved wombat at the Avian, Reptile and Exotic Pet Hospital of Sydney University in Camden. Source: Courtesy of Dr Lorenzo Crosta
Can human beings help these animals reproduce?
Asked whether certain species could be bred in captivity and then released into the wild, Dr Crosta acknowledged that it's not an easy task.
"We have to think of various things. First, if it's possible to reproduce animals sufficiently in captivity. Then, if the animals reproduced in captivity are then able to be released successfully into the wild?
"It really is a multidisciplinary problem. It takes people who are capable of reproducing animals, it takes people who are capable of helping the animals adapt to live in the wild and it takes the receptive environment for the animals to return".
"And it takes genetic variability for the animal population to support itself.
"We have good examples of programs successfully reintroduced and instead there have been some that have been disasters because it has not been possible to put together all the pieces in the puzzle".
