A billion frogs on world's plates
Up to one billion frogs are taken from the wild for human consumption each year, according to a new study.
Researchers arrived at this conclusion by analysing UN trade data, although they acknowledge there is a lot of uncertainty in the figure.
France and the US are the two biggest importers, with significant consumption in several East Asian nations.
About one-third of all amphibians are listed as threatened species, with habitat loss the biggest factor.
But hunting is acknowledged as another important driver for some species, along with climate change, pollution and disease - notably the fungal condition chytridiomycosis which has brought rapid extinctions to some amphibians.
Absence of essential data to monitor and manage the wild harvest is a large concern
Professor Corey Bradshaw
The new research, to be published in a forthcoming edition of the journal Conservation Biology, suggests that the global trade in wild frogs has been underestimated in the past.
"Frogs legs are on the menu at school cafeterias in Europe, market stalls and dinner tables across Asia to high end restaurants throughout the world," said Corey Bradshaw from Adelaide University in Australia.
"Amphibians are already the most threatened animal group yet assessed because of disease, habitat loss and climate change - man's massive appetite for their legs is not helping."
Amphibians are farmed for food in some countries but these animals are not included in the new analysis.
Indonesia emerged from Professor Bradshaw's analysis as both the largest exporter of frogs - 5,000 tonnes per year - and a major consumer.
This has raised concerns that it may soon experience the declines induced by hunting that have been seen elsewhere in the world, notably in France and the US, where species such as the Californian red-legged frog have crashed.
The researchers suggest that the amphibian trade may mimic the situation with global fisheries.
"Harvesting seems to be following the same pattern for frogs as with marine fisheries - initial local collapses in Europe and North America, followed by population declines in India and Bangladesh and now potentially in Indonesia," said Professor Bradshaw.
"Absence of essential data to monitor and manage the wild harvest is a large concern."
The researchers suggest establishing a certification scheme so exporters would have to prove that their animals had been hunted sustainably.
However, a large portion of the trade in amphibians for the pet trade is conducted illegally, and experts say customs officials in many countries are ill-equipped to spot and deal with illegal consignments.