Earlier this year I reported on the unprecedented Australian bushfires with some reflections of what I was observing during my time as a Visiting Research Fellow at the University of New South Wales – see: How are the Australian bushfires affecting biodiversity? Australia reflections part 4. Karin also wrote a piece about the fires, focusing on the human impacts – see: Climate Change Stories From a Nation on Fire.
At the time scientists and the media were suggesting that perhaps half a billion reptiles, mammals and birds had been killed, a figure that provoked a strong public reaction when accompanied by images of fire-scorched koalas. This was then revised upwards to 1 billion. But it turns out that even a billion is nowhere close to the real number of animal deaths. A new interim report commissioned by WWF-Australia suggests that just under 3 billion animals were either directly killed or displaced. Those which were displaced were vulnerable to feral predators such as foxes and cats, or more likely to succumb to starvation. An article in The Guardian about the WWF-Australia report is worth reading – here’s the link.
The actual figure is 2.69 billion individual animals. Think about that for a moment. That’s about equivalent the number of people living in India and China combined. This is the breakdown for the different animal groups that were assessed:
● 143 million mammals
● 2.46 billion reptiles
● 180 million birds
● 51 million frogs
One thing should be immediately apparent: this is not a complete list of the “animals” that have been killed. A lack of data means that fish, turtles and (crucially) invertebrates such as spiders, bees, beetles, and earthworms, were excluded. Those invertebrates live at much higher densities than any of the animal groups that were assessed and indeed are the sole or principle food for many of those species. The number of insects required to support just the insectivorous birds is staggering: globally, birds are estimated to eat 400-500 million tonnes of insects and other arthropods every year.
Even if we were to consider just the larger invertebrates, those bigger than say 0.5 cm in length (which are a minority – most are considerably smaller), then then the true scale of the animal deaths is going to be one or two orders of magnitude higher. Or possibly more. Thirty billion, 300 billion, 3 trillion…? Who knows? It’s impossible to estimate, we just don’t have enough information about those organisms.
The other major component of wildlife that is missing from the report is the plants. I know that studies of plant mortality are being undertaken at the moment and it will be important that this is given the same level of publicity as the assessments of animals.
Writing in the foreword of the report, Dermot O’Gorman the CEO of WWF-Australia pointed out that: “It’s hard to think of another event anywhere in the world in living memory that has killed or displaced that many animals. This ranks as one of the worst wildlife disasters in modern history”.
I disagree. I think it’s THE worst wildlife disaster in terms of the scale of animal losses over such a short period of time. No doubt deforestation and destruction of grasslands in South America, Asia and Africa has killed more animals and plants. But that’s over a timescale of decades to hundreds of years. Australian wildlife was devastated in a matter of months. And no one knows exactly what the 2020-21 fire season will bring. But I think that we can safely predict further impacts on wildlife – and people.