Half of Europe's frogs face extinction

Steve Connor, The Independent 25 Sep 08;

More than half of all amphibian species in Europe could become extinct by 2050 because of a combination of habitat loss, infectious diseases and the effects of climate change, scientists have found.

The latest assessment of frogs, toads, salamanders and newts suggests many will be severely threatened in the coming decades, especially in southern Europe where the climate is expected to become significantly warmer and drier.

But even familiar British amphibians such as the common frog and toad are highly vulnerable, said Trent Garner, of the Zoological Society of London.

"Published projections show that climate change alters amphibians' habitats so we expect a large number of species to be faced with loss of habitat and, ultimately, extinction," Dr Garner said yesterday.

"In the UK, we are already seeing common toads losing condition and experiencing reduced survival. As climate change continues to impact habitats, the situation gets far worse for these native species," he said.

A succession of mild winters has meant hibernating toads in Britain have emerged early from their winter sleep and become sickly because food is not available.

Sir David Attenborough also voiced his concern about the threat to amphibian species. "Amphibians are the lifeblood of many environments, playing key roles in the functions of ecosystems, and it is both extraordinary and terrifying that in just a few decades the world could lose half of all these species." Sir David said.

In addition to climate change and habitat loss, a deadly skin fungus called chytrid that has killed many amphibians around the world has been found in Britain.

Dr Garner said the chytrid fungus may have arrived with alien species, notably the African clawed toad used in research. British amphibians are also being attacked by ranaviruses, which kill thousands of frogs, toads and newts each year. These may have been introduced with the release of the North American bullfrog.

There are more than 6,000 known species of amphibian and a 2004 assessment suggested that at least a third of them are threatened with extinction.

Amphibians facing a wipeout by 2050
Sir David Attenborough has joined scientists in an alert on how climate change and disease may lead to extinction
Lewis Smith, Times Online 26 Sep 08;

Half of Europe’s amphibian species could be wiped out in the next 40 years. Scientists from the Zoological Society of London say that the combined force of climate change, pollution, disease and habitat loss and degradation has left many with “nowhere to run”.

After assessing the amphibians’ prospects, they predicted that more than 50 per cent of the 81 species native to Europe faced extinction by 2050.

Even surviving species, they said, were likely to suffer a decline in numbers and distribution, including the common toad in Britain, which is already being affected by climate change.

Trent Garner, Jonathan Baille and Helen Meredith announced their findings last night at a ZSL event hosted by Sir David Attenborough, the naturalist and broadcaster.

They said that in the short term many species would need to be taken into captivity because they faced extinction in the wild.

In the long term, although pollution could be reduced and habitats restored in limited areas, the survival of amphibians in Europe depended on solutions to climate change and cures to diseases being found.

They based their predictions on a review of past published papers and modelling programmes, combined with findings from current conservation projects.

Sir David described amphibians as “the lifeblood of many environments” because of the important role they played in them, such as providing food for larger animals.

“It is both extraordinary and terrifying that in just a few decades the world could lose half of all these species,” he said. He hoped “that we will not be hearing the dying croaks of these amazing creatures in the years to come”.

Dr Garner, a ZSL research fellow, said that the species most under threat were those that could not escape threats by migrating into new territories. Island species were particularly vulnerable but even mainland European amphibians faced geographical barriers such as mountains.

Dr Garner said that Lataste’s frog had declined in numbers because of the encroachment of agriculture and urban development into its sole habitat, the Po flood plain in northern Italy. It had never been found above 700 metres and the Alps blocked its route to northern Europe.

One of the most threatened amphibians in Europe is the Majorcan midwife toad, the male of which carries the fertilised eggs until they are ready to hatch.

The toads are limited to only 30 sites in Majorca, on which the deadly chytrid fungus was found recently.

On Sardinia, there are seven amphibian species found nowhere else in the world but they could all disappear because of the spread of chytrid fungus. The disease has already killed masses of Sardinian painted frogs and affected the numbers of the Sardinian brook newt.

The main threat facing the Alpine salamander, which is rarely seen outside its mountain environment, is climate change. Rising temperatures, the scientists say, will force the salamander to climb higher in search of cooler conditions until it runs out of mountain.

Dr Garner described the Alpine salamander as one of the oddest amphibians known to zoologists – the young cannibalised each other while still in the womb until only two were left.

In Britain the effects of climate change has already disrupted the hibernation of common toads. Warmer weather in winter has hampered the toad’s ability to shut down its bodily systems, forcing it to use up extra energy. This leaves it in a poorer condition when it wakes up in the spring.

Speaking shortly before last night’s presentation, Dr Garner said: “A lot of amphibian habitat is going to become unsuitable. That puts them at risk. Combined with that there are other pressures including disease, existing habitat loss and pollution. I think greater than half are threatened with extinction by 2050.”

Ms Meredith, who coordinates the amphibian element of ZSL’s Edge (Evolutionarily Distinct and Globally Endangered) programme, said: “Clearly there is no time to waste if we are to prevent further species loss and effectively conserve unusual, threatened and neglected amphibian species in the wild.”

Assessments carried out to establish the level of threat faced by amphibians worldwide concluded that almost half are in decline and a third face extinction. Dr Baille is the ZSL’s conservation programmes director.

Last chance to see

Natterjack toad Found commonly in Britain and is likely to suffer from effects of climate change. It lays its eggs in temporary pools, so tadpoles will be in a race to turn into toads before the water dries out

Sardinian brook newt Found only in Sardinia. During courtship the male seeks out females and grabs them with its mouth, often copulating by force

Olm A type of salamander that has retained gills. It never leaves water and is found in underground caves. A lifetime spent in darkness has left it bright white in colour

Iberian midwife toad Its name derives from the male’s practice of caring for its eggs. He carries the eggs about in his hind quarters until they are ready to hatch, whereupon he takes them to a pond