Mountain Chicken Frog Conservation

The mountain chicken (Leptodactylus fallax) is not a chicken. It is a frog. Officially named the Giant Ditch Frog and locally known as a mountain chicken (for its large size and the fact that it is eaten for food), the mountain chicken is a frog that lives in Dominica and Montserrat.

Since the onset of an epidemic of chytridiomycosis on Dominica in 2002 and on Montserrat in 2009, the mountain chicken population declined by over 90%. This species is now Critically Endangered according to the IUCN Red List. The reality is that there are fewer than 100 wild individuals on Dominica and only two on Montserrat, that we know of despite field research over many years.

ZSL and partners are working on both in-situ conservation efforts and ex-situ captive breeding, with the hope of bringing this species back from the brink of extinction.

Why we are there

The mountain chicken populations on both Dominica and Montserrat have undergone significant declines associated with the arrival of the fungal disease, amphibian chytridiomycosis, caused by the fungal pathogen, Batrachochytrium dendrobatidis.  

The mountain chicken is of cultural importance to the people of Dominica, where the frog was the national dish. It was also widely eaten in Montserrat before the onset of the decline.

The immediate future of the species is uncertain with the most realistic hope on Montserrat being through captive breeding and release. On Dominica, the situation looks a little better with some evidence of a possible slight recovery of the population (although this is from no detectable frogs to fewer than 100 – prior to the chytridiomycosis epidemic, the population was in the tens of thousands). The project is guided by scientific research which has underpinned decisions on surveys and interventions required to ensure the long term survival of this species. There is ongoing research on the emergence, epidemiology and impact of chytridiomycosis in mountain chickens. On Dominica, this work is assessing the current size and infection status of the remnant mountain chicken population and sympatric amphibian species. 

There is no known effective way of treating frogs with chytridiomycosis in the field or of eradicating the disease from the wild, which means intense, hands-on management is needed. Mountain chickens are the perfect model species from which to learn about the impact, epidemiology and treatment of chytridiomycosis and the results of this research have the potential to guide conservation measures for many other amphibian species that are impacted by this and similar diseases. 

Key Achievements & Goals

Our goal is to have healthy populations of mountain chickens as a flagship species for the natural and cultural heritage of Dominica and Montserrat.

Achievements:

• Rapid response to population declines attributed to the fungal disease, amphibian chytridiomycosis.
• Established a conservation breeding facility for mountain chickens in Dominica.
• Developed a molecular diagnostics laboratory in Dominica.
• Capacity building: trained in-country personnel in mountain chicken husbandry, field survey and laboratory techniques.
• Conducted research into the emergence and epidemiology of chytridiomycosis in the mountain chicken.
• Worked with partners to develop a 20-year conservation action plan for the mountain chicken.
• Key partner in the ex-situ conservation breeding programme.
• Maintaining a population of mountain chickens in a biosecure facility at ZSL London Zoo; frogs have been bred in captivity and released in Montserrat.
• Undertaken research to improve the captive husbandry and pre-release health screening of mountain chickens.
• Trialled the treatment of amphibians in the wild for chytridiomycosis for the first time. Read the news story.

Latest research 

• January 2016: A study co-authored by IoZ’s Professor Andrew Cunningham and PhD student Michael Hudson tested the in-situ treatment of individual mountain chicken frogs using the antifungal drug, itraconazole. They found increased probability of survival and loss of the fungal infection for treated frogs compared to non-treated animals. Results suggest that in-situ treatment of individuals with the drug could be a useful short term measure to reduce the chytridiomycosis-induced mortality rate and to increase opportunities for other conservation actions, including  facilitating population survival in the wild during periods of high disease risk. 
• August 2016: Findings from research co-authored by IoZ’s Professor Andrew Cunningham and PhD student Michael Hudson suggest that the decline of the mountain chicken across its range is amongst the fastest recorded for any species, with island-wide population collapses due to chytridiomycosis occurring within 18 months on Dominica and under one year on Montserrat. There’s an urgent need to build mitigation capacity where amphibians are at risk from chytridiomycosis and to prevent the spread of the disease to new areas. 

For more than 20 years, ZSL has been at the forefront of research on amphibian chytridiomycosis, a disease which has devastated amphibian populations globally. Find out how ZSL's Institute of Zoology is working to fight the chytridiomycosis pandemic. 

Research on chytridiomycosis

• ZSL hosted a scientific event in April 2017 on conserving the mountain chicken frog: the impact of chytridiomycosis under scrutiny. 

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