Australia is baking through another extreme heatwave, with temperatures forecast to reach above 45°C for multiple days in a row across large swathes of the country.
Heatwaves are a deadly threat to humans, disproportionately impacting older people and those with lower incomes.
But it’s not just humans that feel the heat. Many animals can withstand extreme heat through various behavioural responses. For example, dogs pant to cool down and koalas hug the coolest parts of trees.
But when a heatwave occurs, the long periods of higher temperatures may be too much for some animals to handle. Tens of thousands of bats have been killed in heatwave events across Australia. Some birds can only survive a single day of extreme heat before succumbing.
You might think cold-blooded animals, such as insects, will be fine, and will even thrive in the extreme heat. But this isn’t always the case. Thankfully, insects such as ants, bees and beetles have a number of fascinating ways to keep themselves cool. With a few simple steps, we can help them, too.
Ants everywhere
You might be used to hearing that summer brings out ants in large numbers, which doesn’t come as great news to people who don’t want ants in their houses.
It is true that ants increase their activity in warmer weather. But if the heat is prolonged and temperatures are extreme, ants often forage less, staying in the shade or inside their cooler nests.
This is bad news for your kitchen. Houses often act as a cooler, shadier region to forage, and if there are ants out and about, they’re more likely going to head towards the house.
‘Bearding’ bees
The introduced Western honeybee is much better suited to cooler climates, but they’ve adapted to the pressure of hot weather with a range of interesting behaviours.
When it gets hot, honeybees will “beard”. This is where workers hang out in large numbers on the outside of the hive to increase airflow within the hive.
While bearding, bees often “fan” the hive, acting as tiny air conditioners. Individuals will flap their wings to move air around and cool down the inside of their nest. They’ll also collect water to bring inside the hive to cool it down.
A lot of native Australian stingless bees can survive in 40°C heat, but struggle in prolonged heat of these temperatures.
In order to protect these bees in artificial hives, it’s important to cool down the hive using wet towels, or even close the colonies and move them temporarily indoors.
Beetles beat the heat
Summer is a wonderful time for viewing beetles in Australia, particularly Christmas beetles. Generally speaking, a hot day or two will trigger the emergence of these beetles from underground, decorating trees with their sparkling, festive bodies.
During heatwaves, beetles will likely be less active, opting for shadier areas. The hot, dry weather can reduce the availability of their food sources, too, making it hard for them to thrive.
Christmas beetles do have some interesting ways of preventing overheating, though.
For example, their sparkling, hardened wings (known as elytra) can reflect heat. Or, depending on the colour of the beetle, they can trap heat under their wings and then flap them to push it out to cool down.
shotbyrob/iNaturalist, CC BY-NC
Caring for insects
Heatwaves can be a dangerous time for most of our wildlife, including insects, but there are lots of ways we can ensure they don’t swelter.
Adding rocks to birdbaths can provide somewhere for flying insects to land and drink. This is a simple way to help them beat the heat – but don’t forget to regularly clean the bird baths to prevent mosquitoes.
Having a garden with lots of canopy cover can also provide insects with shade. It’s also worth considering the insects arriving in your house during these heatwaves: they may be trying to get the same respite you are, so consider whether or not it’s necessary to remove the one-off visitors.
Hotter temperatures do provide lots of opportunities to observe insects. But consider waiting until dusk or night time to see who is out and about.
If you turn on your porch light on a hot summers’s night, you’ll get to observe a lot of insects. You may even get to see some Christmas beetles, which you can report to an ongoing citizen science project investigating what’s happening to these beloved critters.
by : Caitlyn Forster, Associate Lecturer, School of Life and Environmental Sciences, University of Sydney
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