Earth’s amphibians ‘are sliding towards extinction’; Chinese populations remain threatened, major study finds

Global evaluation of 8,000 species shows 2 out of every 5 amphibians ‘are still in trouble’ from habitat loss and climate change
Amphibians continue to be the most threatened class of vertebrates, with 14 species becoming extinct since 1980

Science

Holly Chik

Published: 11:00pm, 4 Oct 2023

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A new global assessment of more than 8,000 species has added to mounting evidence that many of the world’s amphibians are being driven to extinction, with central and southern China identified as one of the higher risk regions where large concentrations of threatened species live.

Two out of every five amphibians are threatened with extinction, a team of more than 100 international researchers has found, with climate change now a major driver of the decline of the cold-blooded vertebrates, such as frogs, newts, salamanders and caecilians, which are highly sensitive to environmental changes.

The scientists are urging immediate and substantial investments and policy actions to support the survival and ongoing recovery of amphibians, building on conservation efforts, such as habitat protection, that have reduced the extinction risk of 63 species since 1980.

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The findings were published in the peer-reviewed journal Nature on Wednesday.

The evidence shows that “amphibians are still in trouble”, said co-lead author Jennifer Luedtke, manager of species partnerships at Re:wild, a Texas-based environmental conservation organisation, who referred to a 2004 global assessment that found amphibians were the most threatened class of vertebrates.

Globally, 37 amphibian extinctions have been documented – 23 occurred before 1980, followed by 10 more extinctions by 2004 and another four by the end of last year.

The latest research shows that amphibians – which can live both in water and on land – remain the animals most at risk, with 41 per cent of them threatened with extinction, higher than 26.5 per cent of mammals, 21.4 per cent of reptiles and 12.9 per cent of birds.

“Such a high proportion of amphibians are sliding towards extinction. They have to be at the top of the agenda,” said Luedtke, who also serves as the red list authority coordinator of the amphibian specialist group at the International Union for Conservation of Nature (IUCN) species survival commission.

“They have to be a part of that commitment to halt extinctions.”

In December last year, at the United Nations Biodiversity Conference, also known as COP15, governments around the world agreed to “halt human-induced extinction of threatened species and reduce the rate of extinction of all species tenfold by 2050”.

Habitat loss, which affects 93 per cent of threatened species, is mainly driven by agricultural expansion, followed by timber and plant harvesting, and infrastructure development, according to Luedtke.

“While habitat loss and degradation remain the most common threat to amphibians, there is a growing proportion of species being pushed to the brink of extinction by disease and the effects of climate change,” she said.

Between 2004 and 2022, more than 300 species of amphibians edged closer to extinction, according to the study, with climate change the main threat for 39 per cent of them.

Notable concentrations of threatened species live in central and southern China, according to the study, while the greatest concentrations are in the Caribbean islands, Mesoamerica, the tropical Andes, the mountains and forests of western Cameroon and eastern Nigeria, Madagascar, the Western Ghats in India and Sri Lanka.

Co-lead author Kelsey Neam, a species priorities and metrics coordinator at Re:wild, said over-exploitation has been the top driver pushing species closer to extinction in China, but a wildlife protection law has helped reduce their risk.

“Overharvesting is [collecting] individuals either for the pet trade, consumption or medicine – there are a variety of reasons amphibians are collected – but at an unsustainable rate, to the point at which the extinction risk is increasing,” Neam said.

The team pointed to the Yunnan Asian Frog, which had been designated as vulnerable in 2019 on the IUCN red list of threatened species, an improvement from the animal’s endangered status in 2004.

The frog’s population had declined at least 30 per cent over a 10-year period due to overharvesting, according to the IUCN database. It added that local villages have been collecting them for food for more than a decade.

A law making the collection of wild species in China illegal put in place in 2000 has helped to decrease the threat of harvesting, although it is still taking place at reduced levels, according to the IUCN.