One in five reptile species under threat of extinction
Melville said climate change is also affecting the sex ratios of many reptile species. The sex of central bearded dragons, for example, is dictated by their genetics if the eggs are incubated at under 32 degrees. If the nests are hotter than 32 degrees, the offspring with male sex chromosomes emerge as females.
Melville said researchers had “found changes in the ratio of males to females” in areas warming due to climate change.
Since colonisation, about 100 of Australia’s unique flora and fauna species have been wiped off the planet. The rate of loss, which is as comprehensive as anywhere else on Earth, has not slowed over the past 200 years.
The research, conducted by NatureServe, the International Union for Conservation of Nature (IUCN), and Conservation International and Monash University, revealed that efforts to conserve threatened mammals, birds, and amphibians are more likely than expected to co-benefit many threatened reptiles.
But Melville said researching the behaviour, physiology and ecology of individual species was also essential. A species she first described that’s endemic to the Darling Downs region in Queensland, the critically endangered Condamine earless dragon, falls outside protected areas set aside for other species, for example.
“They don’t actually occur in any of the protected habitats there because they’re ecological specialists,” said Melville. “And now they’re only found on the agricultural lands and they’re very vulnerable to increased intensification of agricultural practices.”
Director of the Centre for Ecosystem Science at the University of NSW Professor Richard Kingsford said conservation efforts mainly addressed the manageable threats, like feral animals or invasive weeds, but more complex issues, such as climate change or native clearing, are ignored.
“We have this long record of the economy trumping environmental sustainability,” he said. “What are we doing about climate change, what are we doing about too much water being taken out of our rivers, what are we doing about land clearing.”
Without adequately addressing the major threats, Kingsford says the extinction crisis will only get worse. For example, a recent research project he’s been part of examined bird populations in the burnt Gondwana rainforest area and found they were struggling to bounce back after the Black Summer bushfires.
The research, published in Global Ecology and Conservation, found the most affected rainforest birds were species that eat insects, leaves or fruit.
“We found there were fewer fruit-eating birds in the burnt rainforest than the unburnt areas, which is potentially a bad sign because it might mean that there’s less of that rainforest regeneration happening,” Josh Lee, the study’s lead author, said.
“Rainforests need these birds to eat and then disperse the seeds for them to grow in other parts of the rainforest. If we don’t have the [birds] to help the fire-affected areas of the rainforest regenerate, we are in real trouble.”
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