Amphibians have been treated in the wild for the first time against the global chytridiomycosis (‘chytrid’) pandemic currently devastating their populations worldwide, as part of a pioneering study led by scientists from international conservation charity the Zoological Society of London (ZSL).
Published in the journal Biological Conservation and conducted in partnership with the Durrell Wildlife Conservation Trust, the University of Kent, Chester Zoo and the Government of Montserrat, the paper describes how the established antifungal drug itraconazole can be used to treat amphibians in the wild during periods of particular risk from chytrid outbreaks. Frogs were individually washed for five minutes at a time in a bag containing the anti-fungal bath. While this measure was not ultimately able to stop them dying, the paper demonstrates that this technique has potential to greatly extend the likely time to extinction for any given amphibian population in the face of epidemic disease.
Caused by the fungus Batrachochytrium dendrobatidis (Bd), this chytrid variant has so far infected more than 600 amphibian species globally – causing population declines, extirpations or extinctions in over 200 of these and representing the greatest disease-driven loss of biodiversity ever recorded. Whilst captive breeding programmes offer hope for some, the International Union for Conservation of Nature (IUCN) currently estimates that even with the cooperation of the global zoological community, only around 50 species could potentially be saved from extinction through this approach. Proven, field-based methods will therefore play a vital role in mitigating the risk posed by this disease.
Commenting on the paper, lead author Michael Hudson – jointly based at ZSL’s Institute of Zoology (IoZ), Durrell and the University of Kent – said: “This method represents a valuable addition to the currently sparse toolkit available to conservation scientists who are trying to combat the spread of chytrid in the wild. The treatment explored in this paper could be used to buy precious time in which to implement additional protective measures for at-risk amphibian species.”
The study, funded by the People’s Trust for Endangered Species (PTES) and the Balcombe Trust, was based on ZSL and Durrell’s long-standing work with the ‘mountain chicken’ (Leptodactylus fallax). This critically endangered species, one of the largest frogs in the world, lives exclusively on the islands of Dominica and Montserrat in the Eastern Caribbean.
Expanding on the study, PTES Grants Manager Nida Al-Fulaij said: “This latest breakthrough provides conservationists with an additional weapon in the global fight against amphibian chytridiomycosis. We’re pleased to be supporting this vital work as part of our wider mission to conserve vulnerable wildlife in the UK and beyond.”
Notes to Editors
‘In-situ itraconazole treatment improves survival rate during an amphibian chytridiomycosis epidemic’
The Zoological Society of London (ZSL)
Founded in 1826, the Zoological Society of London (ZSL) is an international scientific, conservation and educational charity whose mission is to promote and achieve the worldwide conservation of animals and their habitats. Our mission is realised through our ground-breaking science, our active conservation projects in more than 50 countries and our two Zoos, ZSL London Zoo and ZSL Whipsnade Zoo. For more information visit www.zsl.org
ZSL and chytrid
The Zoological Society of London (ZSL) is at the forefront of conservation science efforts worldwide to find workable solutions to the global chytrid outbreak. The disease, and its role as a significant driver in amphibian declines worldwide, was first identified by a scientist from ZSL’s Institute of Zoology (IoZ) who, in his role as Chair of the Diseases Working Group of the IUCN Declining Amphibian Populations Task Force, brought together researchers working on amphibian declines in the UK, Australia and the USA. Since this initial discovery, ZSL scientists have continued to play a leading role in combatting the disease through basic and applied research, from understanding how different amphibian species interact with the fungus to the development of practical conservation measures, including in situ disease mitigation. Most recently, a paper published in November 2015 described how an international team led by ZSL researchers succeeded in eliminating chytrid from a population of Mallorcan midwife toads (Alytes muletensis) through the combination of antifungal treatment of animals bought into captivity and environmental disinfection – the first time such a success had been achieved.
People’s Trust for Endangered Species (PTES)
PTES is a UK conservation charity created in 1977 to ensure a future for endangered species throughout the world. Working to protect some of our most threatened wildlife species and habitats, it provides practical conservation support through funding research and internships; providing grant-aid for world-wide and native mammals species conservation; supporting education, training and outreach programmes; and driving public participation via wildlife monitoring surveys, publications, campaigns and events. Priority species and habitats include hazel dormice, hedgehogs, water voles, noble chafer and stag beetles and traditional orchards and native woodlands.
Visit www.ptes.org for more information about PTES or follow us on Facebook and Twitter.
Durrell Wildlife Conservation Trust
Durrell Wildlife Conservation Trust is an international charity working to save species from extinction. Headquartered in Jersey in the Channel Islands, Durrell focuses on the most threatened species in the most threatened places. Established by author and conservationist, Gerald Durrell, in 1963, Durrell is unique among conservation organisations in integrating four core areas of operation: Field Programmes which undertake conservation action where it is needed most, the Academy which builds the capacity of conservation practitioners, the Wildlife Park in Jersey as a centre of excellence in animal husbandry, research, training and education and Conservation Science which underpins all activities. For more information, visit: www.durrell.org
The University of Kent
Established in 1965, the University of Kent – the UK’s European university – now has almost 20,000 students across campuses or study centres at Canterbury, Medway, Tonbridge, Brussels, Paris, Athens and Rome. It has been ranked: third for overall student satisfaction in the 2014 National Student Survey; 16th in the Guardian University Guide 2016; 23rd in the Times and Sunday Times University Guide 2016; and 22nd in the Complete University Guide 2015. In the Times Higher Education (THE) World University Rankings 2015-16, Kent is in the top 10% of the world’s leading universities for international outlook and 66th in its table of the most international universities in the world. THE also ranked the University as 20th in its ‘Table of Tables’ 2016. Kent is ranked 17th in the UK for research intensity (REF 2014). It has world-leading research in all subjects and 97% of its research is deemed by the REF to be of international quality. Along with the universities of East Anglia and Essex, Kent is a member of the Eastern Arc Research Consortium. In 2014, Kent received its second Queen’s Anniversary Prize for Higher and Further Education.
Chester Zoo is a registered conservation and education charity that supports projects around the world and closer to home in Cheshire. Welcoming 1.6 million visitors a year, it is the most visited zoo in the UK; home to over 20,000 animals and more than 500 different species, many of which are endangered in the wild. Through its wildlife conservation campaign, Act for Wildlife, the zoo is helping to save highly threatened species around the world from extinction.