'Chicken' frogs survive in new home
Critically endangered frogs reintroduced to the Caribbean island of Montserrat are surviving in their new home, according to conservationists.
Three months after releasing captive-bred frogs, the Durrell Wildlife Conservation Trust in Jersey, UK reports they are alive and well.
The "mountain chicken" frogs have declined by as much as 80% in the wild.
A fatal fungal disease is affecting amphibians globally.
Described as "iconic", Leptodactylus fallax are one of the world's largest frog species, with females weighing over 900g.
"Due to their size they have very large meaty thighs which they use to leap long distances," said Sarah-Louise Smith, project co-ordinator for the Mountain Chicken Recovery Programme.
Unfortunately this particular attribute caught the attention of local hunters, leading to their curious name.
"Locally their meat is a delicacy, apparently they taste like chicken," explained Ms Smith.
"In the past [it] was served in many restaurants and hotels to locals and tourists that visited the island."
These human pressures were compounded by the threat of the island's active volcano - which has rendered parts uninhabitable since erupting in 1995.
The outlook for the frogs was described as "desperate" when researchers discovered the infectious disease Chytridiomycosis on the island in 2009.
With only two uninfected populations remaining, conservationists from Durrell plus partners from London Zoo, Chester Zoo and Parken Zoo, Sweden set out on an emergency rescue mission to airlift 50 of the frogs from the island.
A dozen of the animals were then relocated to Jersey, UK, where herpetology keepers were able to successfully breed the frogs in captivity.
Following a short trial last year, 33 healthy frogs were released onto the island in January and a field team have spent three months tracking their movements.
"Some of the frogs were calling in the forest in the first night," said Ms Smith who is based on the island.
"Three months later the fact that we still have live frogs in the release site looking healthy and calling is a very encouraging sign."
- The chytrid disease is caused by the fungus Batrachochytrium dendrobatidis
- It penetrates the skin of many amphibian species causing lesions which prevent the animals from taking in oxygen, effectively suffocating them
- According to the Global Bd Mapping Project conducted by Imperial College London, over 500 species have now been recorded as affected by the disease
The team have spent six nights a week radio-tracking the animals, each of which was fitted with an electronic tag before being released.
"Some frogs will be found under ground in burrows or at the bottom of ponds so we would never find them without this technique," said Ms Smith.
"When we find the frogs we collect data such as location, swabs of the skin to test for the chytrid and any signs they might be breeding."
Although the team reported that some of the released frogs have succumbed to the disease, Ms Smith suggested that this was expected and could actually help scientists to better understand the problem.
"All the information we've collected was previously unknown for mountain chicken and will help us understand the processes that are going on so that we are able to make informed decisions on how to manage the species," she told BBC Nature.
Researchers will now be listening out for further signs that the frogs are surviving.
"Between April and September the males have a very distinctive 'whooping' call that echoes around the forest to attract females to their burrow, so we're hoping to start hearing these calls as confirmation frogs are trying to breed," said Ms Smith.
They have also set up microphones nicknamed "frog loggers" to monitor other parts of the island for the calls of survivors.
"We still have a long way to go with our research and there is still a lot about the chytrid that we do not know but there are many people local and international dedicated to the mountain chicken and working hard to make sure we are successful," said Ms Smith.