IT IS not just humans that should be concerned about climate change.
A week after a UN conference wrapped up in Paris, researchers at the University of Queensland have discovered how global warming is placing the survival of crocodiles at risk.
Their study found climate warming meant saltwater crocs were spending less time submerged in water, which they must do in order to eat, socialise, rest and recover and escape predators.
Professor Craig Franklin from the UQ School of Biological Sciences said saltwater crocodiles exposed to long-term elevated water temperature spend less time in the dip once the water temperature exceeded 31.5C.
“We thought that crocodiles — like many animals — would adjust to temperature changes so life continues,” he said.
“However, we were surprised to find they had little capacity to compensate for water temperature changes and seemed to be hardwired to operate at certain temperatures.
“We are not sure what this means, but it’s likely that if the water is too hot, crocodiles might move to cooler regions, or will seek refuge in deep, cool water pockets to defend their dive times.”
Crocodiles usually spend around 11 hours a day submerged underwater for basic survival.
The UQ study exposed crocodiles to three water temperatures: 28C, which is the average temperature during our current summer, 31.5C, which represents moderate climate warning, and 35C for high climate warming.
They found crocodiles simply spent less time underwater at the higher temperatures.
“Their submergence times halved with every 3.5C increase in water temperature,” lead author and PhD student Essie Rodgers said.
She added that the high 30s to low 40s was the “upper lethal temperature” for crocodiles.
Prof Franklin said more research on other crocodile performance traits that could influence the ability to survive future climate change was needed before scientists could fully understand the effects of elevated water temperatures.
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