Chester Zoo shares concerns as world’s largest frog becomes virtually extinct

One of the world’s largest frogs is on the brink of extinction, according to conservationists.

New surveys of the critically endangered mountain chicken frog suggest that fewer than 50 remain in the wild, highlighting the need for urgent action to save the species from extinction.

Conducted by a team of global conservationists, including amphibian experts from Chester Zoo, along with government representatives and NGOs, the surveys found only 23 frogs living on the island of Dominica, two of which were found dead on the road.

The island of Dominica is now the only place on Earth that is home to the last wild population of mountain chicken frogs after the species was wiped out from five other Caribbean islands. In a race to save the last remaining wild population, conservationists say that urgent attention is needed to protect the charismatic species from complete extinction in the wild.

About mountain chicken frogs

The species suffered a 99% population loss over the last 20 years due to the arrival of the deadly chytrid fungus: a disease which has caused drastic declines in around 500 frog species worldwide and conservationists have no way of removing it from the environment in the wild.

In addition to facing disease, the new survey also revealed other threats that have added to the challenge of protecting the species: severe droughts and flooding because of climate change, the loss of suitable habitat, poaching for food and the introduction of invasive species, such as feral cats, dogs, Cuban tree frogs and pigs.

At almost 1kg — as much as a bag of sugar — the mountain chicken frog is one of the world’s largest amphibians, weighing over 30 times more than the UK’s most common frog.

Kieran Richardson, Curatorial Assistant for Ectotherms at Chester Zoo and responsible for coordinating the conservation breeding program for the species across the whole of Europe, said:“This is one of the most threatened amphibians in the world, and a crucial part of the ecology of the islands where it lives. Sadly, Dominica now has the last wild mountain chickens following their extinction on the island of Montserrat and across other areas of the Caribbean.

“While it is promising to see that there are still some frogs that are breeding on the island, it is incredibly alarming that the population has become so small that the species is now virtually extinct.”

Surveys

Surveys were conducted over 26 nights in two regions of the island of Dominica, leading to a total of 960 combined hours of searching by 28 conservationists. Despite one area being thought of as a stronghold for these large amphibians, only five frogs were found in this region, while 18 were found in another area.

However, the group found one adult male frog that was also caught during a survey in 2015, making this individual at least 11 years old and meaning that he survived the chytrid pandemic.

The recent survey is one part of the Mountain Chicken Recovery Programme – an international collaboration bringing together expertise from across the Caribbean and Europe to create a future for this species. The mission to save the mountain chicken frog includes the team also establishing safety-net breeding populations, investigations into resistance to chytrid fungus and the ground-breaking development of treatments for the disease.T

The Mountain Chicken Recovery Programme is a joint partnership between Chester Zoo, ZSL, Durrell Wildlife Conservation Trust, WildDominique, Nordens Ark, Riga Zoo, Fauna and Flora, The Government of Montserrat’s Department of Environment and The Forestry, Wildlife and Parks Division of the Government of the Commonwealth of Dominica.