By Richard Black
Environment correspondent, BBC News website, Barcelona
Golden poison frog: A Colombian species threatened by habitat loss
Almost three years ago, I sat in a hotel conference room in Washington DC and heard that it would cost nearly half a billion dollars to save the world's amphibians.
Cheaper than the Iraq invasion, tiny compared to the Wall Street crunch - but a lot of money nevertheless.
Here at the World Conservation Congress are many of the scientists who were present that sunny Washington morning and released their prescription for salvation, the Amphibian Conservation Action Plan.
So three years on, it is time to ask: how are you doing?
First, the money; did it show up?
"It's hard to say, because there have been a lot of other initiatives as well such as Amphibian Ark, which has a lot of facilities," says Claude Gascon, co-chair of the International Union for the Conservation of Nature (IUCN) Amphibian Specialist Group and a senior scientist with Conservation International (CI).
"But from our perspective we've probably had about $10m which has gone directly into tip-of-the-iceberg sites that have been very important for conserving the last of a species."
On firm ground
So this is how last-ditch conservation efforts can work for amphibians.
You go to a region where there is a strong chance that certain species will wink out of existence, and you get your hands on a piece of land where they still live.
In Colombia, a link with two other groups, the American Bird Conservancy and ProAves, enabled the purchase of a 1,100-hectare site. Then, money went in for rangers and a bit of infrastructure and training.
For an initial investment measured in tens of thousands of dollars, the last remnants of a few species can be saved.
In Sri Lanka, the charity struck luck when the government bought patches of forest on an old tea plantation. Any conservation deal has a much higher chance of success when the government and the local community are on board.
Mike Hoffman, another scientist with joint IUCN and CI accreditation, highlights the value of meetings that have brought together expertise from the global and local levels.
"In some of the sessions we've arranged, there's a difference of 50 years between the oldest and youngest people in the group," he says.
"And you can just imagine the information they release, whether the frogs are in a protected area, whether they adapt well or are totally dependent on a pristine forest biome, whether they've been undergoing rapid decline."
Out of the wild
By the time the Amphibian Conservation Summit convened in Washington, the Global Amphibian Assessment had already shown the parlous state of the creatures: one-third were on the threatened species list and 165 species were already believed to be extinct.
An estimated 500 species, it was estimated, could not be conserved in the wild. The only solution was to take them out of their habitat, put them somewhere safe, and wait until conditions returned to something like normal on their home patch.
This is where Amphibian Ark comes to the fore. A joint initiative between IUCN and the World Association of Zoos and Aquaria (Waza), it numbers many zoos and other institutions that are prepared to give shelter to the endangered animals.
It is not as simple as it might sound. Habitat, moisture, temperature, humidity and prey have to be maintained; water has to be kept free of disease.
It is far from an ideal solution. Recent research demonstrates that some animals lose their robustness and resilience in a captive breeding environment as natural selection stops winnowing, and the range of environmental conditions is constrained.
But with species such as the Wyoming toad (Anaxyrus baxteri), whose natural waters are infested with the lethal fungus Batrachochytrium dendrobatidis, it is at present the only option.
The Atlanta Zoo has even built a portable captive breeding kit facility that can be shipped and used on site.
The chytrid fungus is probably the most serious acute threat to amphibians. In some places, it has basically clear-cut species in a matter of a few years.
It can be cured in captivity; the antibiotic chloramphenicol is one agent that does the trick, and seems to give amphibians some residual protection afterwards. But treating entire water systems in the wild is another matter.
Only discovered a decade ago, chytridiomycosis is still a poorly understood enemy.
The pressures on amphibians are many and varied
"In some patches, we're finding individuals that have survived, whereas with others like the golden toad it does seem to be all over," says Russ Mittermeier, CI's president.
"It seems like salamanders are more resistant, and why should that be? So we still have a long way to go."
The discovery that some species, apparently devastated by chytridiomycosis, have just about hung on is giving some hope.
The Atelopus genus of Central and South America - for whom the Red List reads like a stuck record playing the phrase "Critically Endangered" over and over again - is a case in point.
Are these individuals immune - as some entire species appear to be - or just lucky? Can they rebuild a population?
This World Conservation Congress saw the release of another Red List. So how did amphibians fare this time around?
"In the intervening four years, we've had 366 species added to the Red List," says Mike Hoffman, who recently helped co-ordinate Threatened Amphibians of the World, the vast, glossy, information-packed book that CI has just brought out.
"And that's primarily new species just discovered, or ones where the taxonomy has been re-arranged."
This is partly what makes the amphibian world such an exciting one at the moment. Just as species are vanishing, others are appearing to science for the very first time.
"There are now about 6,200 species - that's 10% more than we had five years ago, and that's probably between 50% and 75% of what there is, because a lot of places remain to be explored," says Claude Gascon.
"In Papua, New Guinea and Madagascar, for example, there are probably as many species waiting to be discovered as we know of now."
Making things more complex is the fact that even if chytridiomycosis can be beaten, or if amphibians can evolve their way out of its clutches, myriad other threats are set to persist and grow.
Climate change will raise temperatures and dry wetlands. Other diseases, and pollutants, will spread with increasing human migration.
Hunting continues; above all, so does the relentless spread of the human footprint, turning forests into fields, lakes into building plots and ridges into roads.
Keeping alive all the species we know about, let alone the ones we have yet to discover, is a daunting task, even given the resources that have been mobilised since the launch of the amphibian rescue plan three years ago.
But, says Claude Gascon, we have to try.
"I would argue that the story of amphibians is the story of humans. If we don't get amphibians sorted, the next batch to go extinct may be primates."