Review: One in five reptiles is threatened with extinction

The largest analysis to date of the state of the world’s reptiles warns of the threat to ecosystems as more than 1,800 species struggle to survive.

More than a fifth of all reptile species are threatened with extinction, which could have a “devastating” impact on the planet, a new study warns.

The largest-ever analysis of the state of the world’s reptiles, published in Nature, found that 21% of reptile species are threatened with extinction. From lizards to snakes, such a loss could have disastrous impacts on ecosystems around the world, according to the study.

“We would lose a combined 15.6 billion years of evolutionary history if each of the 1,829 endangered reptiles were to become extinct,” said Neil Cox, study co-director and head of the Biodiversity Assessment Unit at the International Union for Conservation of Nature. IUCN). ) and Conservation International. “It’s an evolution that we could never recover. It would be a devastating loss.

“If we remove reptiles, it could dramatically change ecosystems, with unfortunate side effects, such as increased insect infestations,” he added. “Biodiversity, including reptiles, supports ecosystem services that provide a healthy environment for people.”

Fifty-two experts analyzed data from the Global Reptile Assessment, which has received input from more than 900 scientists on six continents over the past 17 years.

While 1,829 of the 10,196 species are known to be threatened, the status of 1,489 could not be determined. Taking these data-deficient species into account, the authors estimate that a total of 21% are threatened.

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The study conducted by NatureServe, IUCN and Conservation International

Although many reptiles live in arid environments such as deserts and scrublands, most species are found in forests, where they face threats such as logging and land conversion for agriculture. .

The study found that 30% of forest reptiles are threatened with extinction, compared to 14% in arid habitats.

king cobra ( Ophiophagus hannah ), for example, listed as “Vulnerable” globally, is in decline across much of its range in Asia, largely due to loss of forest habitat.

Hunting is also a major threat to reptiles, especially turtles and crocodiles, many of which are in danger of extinction. Another important contributing factor is the introduction of invasive species.

Like birds or freshwater fish, reptiles tend to be less popular than iconic species of land mammals or sea life, but more reptile species are threatened than birds, suggesting that more work is needed to protect them, said Mike Hoffmann, head of wildlife recovery at the Zoological Society of London, and one of the scientists involved in the study.

“From tortoises that breathe through their genitals to chickpea-sized chameleons and giant tortoises that can live for over 100 years, they are absolutely fascinating. Our hope is that this first assessment of the world’s more than 10,000 reptiles will help put them in the spotlight and highlight in some way this diversity and how much we have to lose.”

Reptiles, pest control and much more

In addition to controlling rats, mosquitoes and other “pests”, reptiles provide many other benefits. “They help disperse seeds, especially in island environments,” Hoffmann said.

“We have also made many medical advances through reptile studies. Snake venom, for example, has led to critical drug discoveries, including for the treatment of hypertension.

“The impending doom [de especies de reptiles] could have significant and unforeseen impacts on our environment and our own well-being.

In Australia, home to around 10% of the world’s species, reptiles face an increasing number of threats. “Most of Australia’s threatened reptiles have declined due to habitat loss and predation by invasive cats and foxes,” said Nicki Mitchell, of the University of Australia’s School of Biological Sciences. Western Australia, who also contributed to the study.

“Climate change is an emerging threat to species confined to small habitat fragments, as the microclimates they occupy will change and may no longer be optimal for a population to thrive.”

The study is not a fatality

Scientists have noted that conservation efforts to help other animals are likely to protect reptile species as collateral. “Amazingly, we found that if you set out to protect places where threatened birds, mammals and amphibians live together, you will be protecting many other threatened reptiles at the same time,” said study co-director Bruce Young. and Chief and Senior Zoologist. conservation scientist at NatureServe. .

However, reptiles also require direct, global efforts to protect them, Cox said. The UN Convention on Biological Diversity is due to convene the second phase of COP15 in Kunming, China, later this year, where governments will negotiate new targets to protect biodiversity, including reptiles.

“We need strong conservation plans, global political agreement and full country investment to reverse the looming biodiversity crisis if we are to avert the ongoing extinction catastrophe,” he said. declared.

By Graeme Green. Articles in English

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