Author: Stefan Lotters
Position: Researcher and lecturer
Institution: Biogeography Department, Trier University
E-mail: loetters@uni-trier.de
Additional Authors: Dennis Rodder1, Jon Bielby2, Jaime Bosch3, Trenton J.W. Garner2, Jos Kielgast1,2, Sebastian Schmidtlein4, Michael Veith1, Susan Walker5, Che Weldon6, David M. Aanensen5, Matthew C. Fisher5
Submitted Date: June 18, 2008
Published Date: July 4, 2008
This comment was originally posted as a “Reader Response” on the publication date indicated above. All Reader Responses are now available as comments.

Andreone et al. [1] highlighted the need for pro-active conservation action to prevent Madagascar's megadiverse amphibian fauna from loss. The threat of extinction to it is twofold; habitat loss and emerging infectious disease. Of these, the latter presents the least-quantified threat. The amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd) is a globally emerging pathogen that is known to cause extinction of naïve species even in protected areas (2). In this case 'classical' conservation tools are insufficient (3). Bd has not yet been detected in Madagascar (4). However, its introduction there is possible via the international amphibian trade (5) and Bd's arrival in Madagascar is predicted to have a catastrophic effect; endemics are susceptible to Bd infection (6). Our response to this threat should address in situ and ex situ measures, such as prophylactic conservation breeding, according to the IUCN Amphibian Conservation Action Plan [1,5]. Only a few Madagascan species are currently in captive breeding programs [6], compared to the more than 400 amphibian species known [7]. This demonstrates the necessity of identifying which amphibians are most threatened by Bd when prioritizing species for conservation breeding (http://zims.isis.org/aark...). In order to assess the level of threat that the introduction of Bd poses to Madagascar's amphibians, we ran a risk-assessment with Maxent 3.1.2 ('excellent' results, AUC25% 0.969) [8], based on 'bioclimate' (annual mean, maximum of warmest and minimum of coldest month temperature; annual, wettest and driest month precipitation; http://worldclim.org) and 365 globally distributed Bd presence points (http://www.spatialepidemi...). Results (http://www.spatialepidemi...) 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 [9] and those identified as in situ conservation priorities for amphibians [10]. As no meaningful in situ conservation action is available for the emergence of Bd, captive breeding remains the best short-term option for ensuring the survival of Madagascar’s amphibians.

Author Affiliations
1 Dpt. Biogeography, Trier University, Trier, Germany. 2 Institute of Zoology, London, UK. 3 Museo Nacional de Ciencias Naturales, Madrid, Spain. 4 Dpt. Geography, Bonn University, Bonn, Germany. 5 Dpt. Infectious Disease Epidemiology, Imperial College London, UK. 6 Potchefstroom University, South Africa

References
1. Andreone F, Carpenter AI, Cox N, et al. (2008) The challenge of conserving amphibian megadiversity in Madagascar. PLoS Biology Vol. 6, No. 5, e118 doi:10.1371/journal.pbio.0060118.
2. Skerrat LF, Berger L, Speare R, et al. (2007) Spread of chytridiomycosis has caused the rapid global decline and extinction of frogs. EcoHealth 4: 125-134.
3. Fisher MC, Garner TWJ (2007) The relationship between the emergence of Batrachochytrium dendrobatidis, the international trade in amphibians and introduced amphibian species. Fungal Biology Reviews 21: 2-9.
4. Oevermann A, Schildger B, Feldman S, Robert N (2005) Chytridiomykose bei Tomatenfroschen (Dyscophus antongilii) in der Schweiz. Tierarztliche Umschau 60, 211-217.
5. Mendelson J, Lips KR, Gagliardo RW, et al. (2006) Confronting amphibian declines. Science 313: 48.
6. L0tters S (2008) Afrotropical amphibians in zoos and aquariums: will they be on the ark? International Zoo Yearbook 42, 136-142.
7. Glaw F, Vences M (2007) A field guide to the amphibians and reptiles of Madagascar. 3rd edition. Cologne: Vences & Glaw Publishers.
8. Phillips SJ, Anderson RP, Shapire RE (2006) Maximum entropy modeling of species geographic distributions. Ecological Modelling 190: 231-259.
9. Andreone F, Cadle JE, Cox N, et al. (2005) Species review of amphibian extinction risk in Madagascar: conclusions from the Global Amphibian Assessment. Conservation Biology 19, 1790-1802.
10. Kremen C, Cameroon A, Moilanen A, et al. (2008) Aligning conservation priorities across taxa in Madagascar with high-resolution planning tools. Science 320, 222-226.