
Bushfires push at least 20 threatened species closer to extinction - Cogito
http://theconversation.com/a-season-in-hell-bushfires-push-at-least-20-threatened-species-closer-to-extinction-129533
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Cogito
On a recent thread [0] there was a lot of conversation around various
estimates and news coverage of animal deaths caused by the fires in Australia.

I contacted Professor Chris Dickman [1], the author of the '480 million
affected animals' estimate (now revised up to over 800 million).

He mentioned this article he co-authored that was just published. It expands
on the impact to animals and their habitats and addresses a lot of the
questions people are asking.

He also made some points after I asked him about this extract from the
abstract of a paper of his [2] called "The Responses of Mammals to La Niña (El
Niño Southern Oscillation)–Associated Rainfall, Predation, and Wildfire in
Central Australia":

 _The responses of vertebrates to wildfires are complex, reflecting the
varying food and shelter requirements of different species, their exposure to
predation, and other factors. Vertebrates that shelter above the ground and
are not particularly mobile are often killed directly by fire (Chew et al.
1959; Newsome et al. 1975; Silveira et al. 1999; Simons 1991). Conversely,
species capable of extensive movements such as large predators and birds
frequently escape the flames and may increase in abundance after wildfire when
food resources become available (Loyn 1997; Newsome et al. 1975).,Burrowing
herbivores and omnivores are likely to survive fires and, depending on
predation, may increase in abundance after postfire flushes of vegetation
(Newsome et al. 1975). Postwild-fire decreases in the abundance of some
species have been attributed to a lack of food resources and increased
exposure to predation (Groves and Steenhof 1988; Lawrence 1966; Newsome et al.
1975, 1983)._

Here are his thoughts, with his permission. I provide them in full, but
perhaps the most frightening part is the last sentence "the current fires seem
to be overwhelming these [animal responses to fire] owing to [the fires]
severity and geographical extent":

 _The abstract that you have quoted stems from work carried out in the Simpson
Desert some years ago by myself and others in spinifex dominated environments.
Fires there burn with much less intensity than the fires we have been seeing
in eastern Australia recently, as there is very little leaf litter and the
major vegetation association that burns is spinifex grassland. To give you an
idea of how low intensity and close to the ground the spinifex fires are, you
can actually jump over an advancing fire front (not recommended, but I have
done it in my younger days ...!). In the current forest fires, of course, you
cannot get anywhere close without risk of death._

 _The consequences for wildlife of these two types of fire are very different,
as alluded to in the abstract of the paper. In desert areas fires often leave
large unburned patches where animals can escape, and many can go down into
burrows or fly away. In the current bushfires, by contrast, few refuge patches
of unburned habitat seem to be persisting, the areas of the fires are huge so
lack of resources and post-fire predation become very significant for
survivors, and even many birds are killed while fleeing by the flames and the
smoke._

 _In other words, the abstract is accurate in talking about the variability in
animal responses to fire, but the current fires seem to be overwhelming these
responses owing to their severity and geographical extent._

[0]
[https://news.ycombinator.com/item?id=21985532](https://news.ycombinator.com/item?id=21985532)

[1] [https://sydney.edu.au/science/about/our-people/academic-
staf...](https://sydney.edu.au/science/about/our-people/academic-staff/chris-
dickman.html)

[2]
[https://academic.oup.com/jmammal/article/86/4/689/876336](https://academic.oup.com/jmammal/article/86/4/689/876336)

