Friday, 26 September 2008

Sir David Attenborough Tells London Zoo Audience That European Amphibians Are In Trouble

Sir David Attenborough, Patron of AArk, hosted an evening on 'Amphibians in a climate of change' as an awareness-raiser about the plight of amphibians. Jonathan Baillie, Trent Garner and Helen Meredith gave talks on the current and future challenges facing amphibians. Factors including climate change, habitat destruction and disease that could wipe out more than half of Europe’s amphibians by 2050, according to Trent Garner from the Zoological Society of London (ZSL). Helen Meredith, amphibians co-ordinator for ZSL's Evolutionarily Distinct and Globally Endangered (EDGE) programme, warned: "There is no time to waste if we are to prevent further species loss. "We need to reduce carbon emissions, but also address other pressing factors including habitat destruction and spread of diseases."

Captive Breeding Introduced Bd To Mallorcan Midwife Toads

The Mallorcan midwife toad, Alytes muletensis, is one of the worlds most highly endangered amphibian species. Presumed extinct until 1978, the species was 're-discovered' hiding in the arid Sierra de Tramuntana mountains in the north of the Island; the species has subsequently been the focus of a highly successful captive-breeding and reintroduction program. However, mortalities and subsequent detection of high-prevalence infection by Bd clustered into two adjacent breeding-sites rang alarm-bells. Subsequent investigations, reported by Walker et al in Current Biology showed that introduced Alytes were infected by Bd as early as 1989, and had likely picked up the infection in captivity. The paper reports the first use of sequence-typing to demonstrate that island genotypes of Bd are identical, and unrelated to others found in Europe, strengthening the hypothesis that a single introduction of Bd had occurred. The paper reinforces the need for stringent biosecurity methods to prevent cross-transmission of known and unknown pathogens in captivity. As Kevin Zippel of AArk states "It's a much-needed wake-up call. We must do everything in our power to assess and minimize the risks."

Wednesday, 17 September 2008

6 WCH Manaus

The Sixth World Congress of Herpetology is now over, and a brief report on the opening sessions can be found in the latest issue of Froglog (http://www.amphibians.org/newsletter/Froglog88.pdf). The conference was a roaring success, and not just due to the sloths that chose to roost in the trees at the conference venue or the dolphins that swam by the hotel, clearly visible to those conference particpants basking in the infinity pool. Bd was well-represented at one symposium co-organized by Jean-Marc Hero, Erin Muths and your truly, and talks in the symposium (or given just slightly outside the symposium) ranged from treatment to spatial analyses to a test of the Out Of Africa hypothesis to amphibian trade and infectious diseases. Some of the talks from this and two other symposia (Conservation Genetics and Invasive Herps) will form a special issue of the journal Animal Conservation.

Monday, 11 August 2008

The distribution of Bd in Europe grows.....

Bad news, more Bd to be found in Europe, and this time in one of Europe's most endangered amphibians. As we report in the July issue of Journal of Wildlife Diseases, Bd infection was found in diseased Sardinian brook newts (Bovero et al 2008 Detection of Chytridiomycosis Caused by Batrachochytrium dendrobatidis in the Endangered Sardinian Newt (Euproctus platycephalus) in Southern Sardinia, Italy, J Wildl Dis 44: 712-715). We (the ZSL amphibian disease team and "Zirichiltaggi" S. W. C. Non-profit Association for Wildlife Conservation) have been carrying out further surveys in Sardinia and have found further evidence of infection in Sardinia's native (and endemic) amphibian fauna, along with evidence of Bd-driven mortality.

Monday, 7 July 2008

Meeting the challenge of conserving Madagascar's megadiverse amphibians : addition of a risk-assessment for the chytrid fungus

Frogs from Madagascar constitute one of the richest groups of amphibian fauna in the world, with currently 238 described species. Madagascar may be the only region of the world where amphibians are still surviving in a pre-decline phase, and where pro-active conservation measures are likely to work. Andreone et al. describe the development of an amphibian action plan for Madagascar, and show that Madagascar is a top priority for amphibian conservation. As a reply to Andreone et al, Lotters et al in PLoS Biology extend the argument by assessing the level of threat that the introduction of Bd poses to Madagascar's amphibians. Ecological niche-modelling revealed that there is a high risk of Bd spreading post-introduction over a major portion of Madagascar and areas most suitable for Bd largely overlap with both areas of highest amphibian species richness. This study reinforces the point that conservation efforts need to go beyond 'classical' strategies by incorporating stringent biosecurity measures into their planning.

Monday, 10 March 2008

New breeding captivity program at the Peñalara Natural Park

The local government of Madrid, in collaboration with the Museum of Natural History of Spain and the Durrell Wildlife Conservation Trust, has started a breeding captivity program to save the midwife toad and the Iberian frog from the Peñalara Natural Park.
The population of midwife toad crashed in 1997 as a consequence of the chytrid fungus, while the Iberian frog was extirpated from most part of the area by introduced trouts. After several years of management and studies, most introduced fish have been removed, and the chytrid fungus levels are apparently lower.
The new facilities include three rooms where tadpoles, metamorphs and crickets (used as alive food) are housed under temperature, humidity and light controlled conditions. Thirty-eight tanks of 80 l each are used to keep isolated tadpoles from different metapopulations for approximately one year, and 90 small boxes are used to keep metamorphs growing until they are released in the field. Egg clutches and small tadpoles of Iberian frogs are captured in the field and grow in the breeding facilities to increase their probability of survival. Captivity-born midwife toads will be produced from the last few adults which survive the disease. Animals to be released in the field will be treated with itraconazole and/or high temperatures at the end of the metamorphosis, to prevent them from dying during that critical period.


video

Thursday, 31 January 2008

New Bd ecology paper


A new paper from Bosch & Rincon, on the first evidence of an indirect effect of chytridiomycosis in the field, is in press in Diversity and Distributions. We have documented how the disease may indirectly influence community structure by altering biotic interactions in which affected species participate. In Peñalara Natural Park (Central Spain), the common toad (Bufo bufo) has significantly increased its number of breeding sites after chytridiomycosis nearly extirpated the midwife toad (Alytes obstetricans). An experiment demonstrated that breeding B. bufo adults strongly avoided laying eggs in water containing A. obstetricans tadpoles, accounting for observed patterns of pond use. Bufo bufo is far less severely affected by Bd, spends less time in the water and has higher fecundity than A. obstetricans. So, inter-specific differences in the severity of the effects of the pathogen may modify their biotic interaction indirectly favouring one of them.
We think this kind of indirect effect may be a relatively frequent consequence of chytridiomycosis, and further attention must be paid to this to fully understand the deep effects of the disease on amphibian communities.

Wednesday, 23 January 2008

Welcome to EDGE-Amphibians!


The Zoological Society of London (ZSL) has launched a major conservation program that is focused on drawing attention to the plight of amphibians. EDGE (Evolutionarily Distinct and Globally Endangered) has at its core the aim of identifying the planets most endangered species based on phylogenetic, as well as more conventional, conservation criteria. EDGE species are in cases the last surviving members of groups that have had long evolutionary histories, yet they 'are unfamiliar to both conservationists and the public, and are frequently overlooked by current conservation initiatives'. EDGE Amphibians has identified a list of Top 100 endangered species, for which extinction would represent a disproportionate loss of the worlds amphibian biodiversity. And, surprise surprise, a number of these species are at risk from chytridiomycosis. Infection by Bd is implicitly recognised in the EDGE site as a major driver of declines, and EDGE provide information on the major amphibian diseases in the Conservation section of their website. Well done EDGE and good luck!

Following is a short movie where The EDGE's own Helen Meredith explains more about EDGE Amphibians.

Tuesday, 8 January 2008

Happy New Year in the Year of the Frog

Welcome to 2008, the year the Amphibian Ark has tasked to be the Year of the Frog (Click here to visit site ) in an effort to raise awareness of the AArk’s lead role in coordinating public awareness and global captive breeding programmes for species at greatest risk of extinction. Of course, many of those species are at risk due to chytridiomycosis, not least of which is the Mt Chicken frog, Leptodactylus fallax, a species nearly eradicated from Dominica by the emergence of Bd. The frog is found also on Montserrat, where the species range was severely impacted by volcanic activity in the 90s, but where Bd appears not to have yet reached (see Garcia et al. 2007 Oryx 41(3):398-401). On Dominica, chytridiomycosis was first reported in L. fallax in December of 2002 and in less than 1.5 years Dominican Mt. Chicken frogs declined by an estimated 70% (Malhotra et al. 2007 Applied Herpetology 4:177-194), with current estimates at 8,000 individuals: the IUCN currently lists the species as Critically Endangered. The Zoological Society of London has established a small captive population for the purposes of captive breeding (Click here to read article) and the herpetology staff of ZSL London Zoo is currently battling Bd infection in this population with Itraconazole. Results so far are extremely encouraging: previously diseased males appear healthy, test negative for infection and are starting to exhibit secondary sexual characteristics.

Animal Conservation published in the last issue of 2007 a featured paper by Doug Woodhams and coauthors (Woodhams et al 2007 Animal Conservation 10:409-417), along with commentaries and a reply by the authors of the original paper. The featured paper describes the latest in a series of papers examining the relationship between amphibian species, the production of antimicrobial peptides and susceptibility to chytridiomycosis. Another recent publication by Seimon and co (Seimon et al 2007 Global Change Biology 13:288-299) provides evidence that dispersing amphibians bring Bd along with them. Furthermore, the dispersers are taking advantage of recently available habitat made available through climate change.

2008 Year of the Frog is here!



This year is going to be a busy one, and a major global focus is going to be raising awareness of the causes and effects of the amphibian extinction crisis. The Patron of AArk, Sir David Attenborough, has kicked off the year with an impassioned plea; "Today, amphibians can be found in enormous variety and occupy a wide range of water and land habitats, except for the oceans and the frozen polar regions. They are so familiar to most people that they have become part of the myths, legends, and folk tales of many cultures. Yet their habitats are being destroyed at such a speed that now many species may disappear before we even discover that they exist. Infections of chytrid fungus, for which there is no known cure, are today spreading rapidly and threatening entire species. There is thus the real possibility that much of an entire category of animals may become extinct unless we prepare to act quickly." [link] I feel that this is a good rallying call, and despite the gloom there is much to be positive about. That AArk is occurring at all is testament to the commitment of the conservation and scientific community to address the problems facing amphibians. Lets belive that 2008 will be the year that Science and Policy weld together to address the amphibian crisis. Stay tuned to this blog for further news, synthesis, treatment protocols and the launch of the Global Bd Mapping Project.