Wildfires in Australia are much in the news as I write this,
and they will still be burning when I write this column next month. At least 25 people have died in the fires and
thousands are now homeless. That is
tragic enough but the scale of destruction is many orders of magnitude greater
for the wildlife affected by the fires.
It has been estimated that more than a billion animals may have perished
already. Bushfires have been a fact of
life in Australia for thousands of years and a unique ecology has evolved, not
only to cope with fires, but to thrive on them.
I have seen grass trees bursting into leaf when all the rest of the
vegetation around them is blackened, and some species of eucalyptus trees will
not germinate until the seeds have been charred. There is even a beetle that can detect
infra-red radiation and will seek out burned areas to eat the resulting
corpses. But that ecology has developed
to cope with occasional fires that blow through relatively quickly one area at
a time. The current fires are on a
different scale altogether where several join up and become large enough to
create changes in the weather. On this
scale, even animals that can run or burrow their way out of danger will have no
habitat to return to and will probably starve as a result. The loss is not just about the larger
animals, the destruction of insect life, and the detritivores that live in the
leaf litter, even the microbes in the soil will have been wiped out. I have seen several posts from researchers
studying particular species such as velvet worms and grasshoppers who are
unable to enter the habitats they are studying and suspect that their study
subjects may now be extinct.
The cause has been firmly established as global heating, a fact
that the Australian government will eventually have to accept however reliant
they are on their coal-based economy.
Perhaps the general population will also see that driving V8 cars and
screaming about in powerboats is no longer acceptable behaviour.
Closer to home, we are not yet affected by wildfires to any
great extent but we are in the middle of one of the wettest winters I have ever
experienced and major floods and droughts are becoming commonplace. All of these are predicted by climate change
models and not a week goes by without reports of new records being broken,
whether that be ocean temperatures, wind speeds, or atmospheric carbon dioxide
concentration.
I am concerned that the wet winter may have affected many
species of hibernating insects. The
ground has been waterlogged for many weeks now and the bumblebees, solitary
bees and wasps may not survive it.
Insects hibernating underground have to try and choose ground that will
not get washed away or flooded or too frozen.
Even if they manage that, places that stay damp can harbour species of
fungus that invade their bodies and eat them from the inside. There is a particular genus of fungus called
Cordyceps that invades and even changes the behaviour of insects. There are hundreds of different species and
each one targets a different species of insect. They can attack both active insects like
ants as well as hibernating insects such as beetles. There is a particular species called Cordyceps
militaris that is found throughout the northern hemisphere and is commonly
known as the caterpillar fungus. If you
see some bright orange club-shaped fungus (Cordyceps means club-headed)
sticking out of your lawn, then if you dig it out carefully you may find the
remains of a caterpillar at its base. This
is gruesome for the caterpillar, but looking on the bright side the mycelium is
very nutritious for us humans and has many vitamins as well as cancer
suppressing properties, not to mention its reputed effect on male performance.
My apologies if you ere expecting a picture of a grass-tree. I need to go back to 1999 and find the right slide.
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