February 4, 2019 by Sean Maxwell And James Watson, The Conversation
The recent heatwaves have proved deadly to many Australian
animals, from feral
horses to flying
foxes.
And it's not just heatwaves that can cause mass die-offs. Last
year, flooding rain wiped
out entire Antarctic penguin colonies, while drought has
previously caused mass mangrove diebacks around the Gulf of Carpentaria.
These events generate headlines, but what about the aftermath? And
are these catastrophic events part of a wider pattern?
Our research describes
how species have responded to extreme
weather events over the past 70 years. These responses
can tell us a great deal about how species are likely to cope with change in
the frequency and intensity of extreme events in
coming years.
We reviewed 517 studies, dating back to 1941 and conducted
throughout the world, that examined how birds, mammals, fish, amphibians,
reptiles, invertebrates or plants have responded to droughts, cyclones, floods,
heatwaves, and cold snaps.
We found more than 100 cases of dramatic population declines.
In a quarter of these cases, population
numbers showed no sign of recovery long after the event. And
in most cases, extreme events reduced populations of common species that play
an important role in maintaining ecosystem integrity.
For example, extreme drought in the 2000s drove massive population
declines of invertebrate freshwater species across
Australia's Murray-Darling Basin, and populations of buffalo,
waterbuck, and kudu along the Zambezi River in Zimbabwe suffered severe
and persistent declines following droughts in the 1980s.
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