Thousands of flying foxes succumb to heat
Climate change and its planet-threatening effects are now irrefutable to all but environmentally negligent politicians, pseudo-science and die-hard traditionalists.
But when the bats start falling out of the trees, it really is time to take stock.
It was late November (still spring in the antipodes), and the temperature outside my office in Cairns (north-east Australia) was nudging 43 degrees C.
We were in the midst of a prolonged period of unprecedented pre-summer heat, and bushfires were raging across vast areas of North Queensland.
In the Cairns CBD there was a palpable odour of rotting flesh along some of the tree-lined streets. It was coming from hundreds of dead bats that had succumbed to heat exhaustion.
I don’t know how many spectacled flying foxes (fruit bats) in the wider Cairns region actually perished in the two-week ‘burner’, but there would have been many thousands.
Trish Wimberley of the Australian Bat Clinic told AAP that fruit bats can’t sustain an internal temperature over 40 degrees (exactly like humans can’t), and they just drop out of the trees – dying.
She said 80 percent of one Cairns colony was lost and populations in four other sites had crashed.
The North Queensland fruit bat is critically endangered, and Wimberley said seeing hundreds and hundreds of them dead and dying was heartbreaking.
Unfortunately, evolution has not prepared the spectacled flying fox well when it comes to rehydrating in extreme heat. Unlike most other bats, which drink on the wing or actually stop to take on water, the fruit bat gently skims the water’s surface, collecting droplets on its chest fur. It then finds a safe place to land and lick off the moisture.
In normal conditions, that technique works fine, but when temperatures soar, chest-skimming for water doesn’t deliver the goods.
(Footnote: Having lived with the nightly pandemonium of a bat colony in the bush near our house, it would be easy to say, ‘Oh the relief!’ But that would be like saying the slaying of millions of North American bison solved the fly problem. Wouldn’t it?)
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