Lessons of the Lost
Amphibians are all but gone, bequeathing us lessons that must not be squandered
Planning for Posterity
Conservationists have been overwhelmed by the amphibian crisis. In the atmosphere of ongoing declines, we realized that there was no framework to address a challenge of this magnitude or rapidity. Even worse than problems of scope and scale is the reality that conservationists, collectively, are stymied by the central problem of not knowing what to do. We have decades of experience as first responders in aid of species threatened by the familiar challenges of habitat loss, pollution and overharvesting. In many of these cases the solution is straightforward (often, stop eating that species), even if the sociopolitical and economic challenges can be formidable. The appropriate conservation response for amphibians perishing from disease must await a real breakthrough in disease control. There is no vaccine for any fungal disease known to affect humans or livestock, despite the high value we place on those species. Breakthroughs in research take time, and the amphibians are teaching us that time is tragically correlated with functional and actual extinctions. Climate change is another difficult conservation challenge for amphibians, but the threat of climate change is shared by all species, so at least amphibians will benefit from global programs conservationists are now battling to enact worldwide.
The IUCN has produced an Amphibian Conservation Action Plan to outline the basic endeavors necessary to confront the global amphibian crisis. The plan outlines important programs to protect habitat, reduce pollution, control commercial harvest, understand the consequences of climate change, and expand efforts toward population monitoring and taxonomic studies. Two major elements of the plan focus on the understanding and control of emerging infectious diseases and on the conundrum of what to do in the case of epidemics. The IUCN has charged the Amphibian Specialist Group (http://www.amphibians.org) and the newly organized Amphibian Survival Alliance with monitoring amphibian status worldwide and implementing an action plan. Meanwhile, awaiting the necessary breakthroughs in research and disease control, IUCN has charged Amphibian Ark (http://www.amphibianark.org) with the difficult task of organizing a global network of captive survival-assurance colonies of those species that can no longer be safeguarded in the wild. Nobody prefers a future in which amphibians on this planet are to be found only in safe-house aquaria at zoos and other institutions, but that is the best hope for some species right now.
Amphibians are teaching us lessons about the state of our planet. Waves of unstoppable fungal epidemics have all but silenced the wonderful frog choruses, all but eliminated the massive hidden biomass of invertebrate-consuming salamanders, and they have done so in some of the most remote and pristine areas left on our planet, including national parks. Those remote and fully protected areas may end up little more than ghosts of epidemics past. We remain pitifully ignorant of the basic biology, and the fates, of the ever-mysterious earthworm-like caecilians. Jonathan Campbell’s work at Reserva del Quetzal in Guatemala indicates that it has lost about 70 percent of its amphibian species. Karen Lips’s site in the Parque Nacional G. D. Omar Torrijos H., near El Copé, Panama, lost at least 30 species of amphibians (41 percent of the total) in the span of a few months during 2004 and 2005.
I am by profession an amphibian taxonomist, if nowadays a part-time forensic taxonomist, and I am by necessity an amphibian conservationist. The thrill of discovering and naming new species never gets old, but documenting the disappearance of any species—especially ones that I discovered and named—feels like a personal blow every time it happens. I never anticipated that my career as a neontologist in the life sciences would so closely resemble paleontology. There is a parallel between what amphibian taxonomists do these days and what homicide detectives do. Both arrive at scenes of mayhem. Maybe they solve the crime, but they are powerless to undo it. Yet the difficulty of demonstrating actual extinction gives me a flicker of hope. I hope that I am wrong in some of my scientific endeavors—a posture I never anticipated as a graduate student.
Our powerlessness in this terrible crisis must be balanced by increased efforts in realms that we can control, such as reducing carbon emissions to protect what habitat remains from chemical and physical disruption. We can go further and restore what has been wounded but can still be salvaged. We need to inspire and fund truly innovative research on pathogens in order to better predict and thwart emerging infectious diseases. The lessons we learn here will extend far beyond the amphibians. We must support funding for programs such as the Amphibian Ark and the Amphibian Survival Alliance. We must keep looking for species gone missing, and continue biodiversity surveys, despite the sometimes paralyzing depression that both activities can induce in this era. But especially, we need to pay close attention to the lessons that legions of dead amphibians are teaching us. I note with some satisfaction that our colleagues in bat research and conservation did not spend a decade arguing whether the fungus that causes white-nose syndrome could possibly eliminate entire colonies of bats in a single season. Our colleagues assumed that it was possible and reacted quickly. We can thank the amphibians for leaving us that lesson, but at such cost.
- Cheng, T. L., S. M. Rovito, D. B. Wake and V. T. Vredenburg. 2011. Coincident mass extirpation of neotropical amphibians with the emergence of the infectious fungal pathogen Batrachochytrium dendrobatidis. Proceedings of the National Academy of Sciences (USA). doi: 10.1073/pnas.1105538108.
- Collins, J. P., and M. L. Crump. 2009. Extinction in our Times: Global Amphibian Decline. Oxford University Press.
- Crump, M. L. 2000. In Search of the Golden Frog. Chicago: University of Chicago Press.
- Fisher, M. C., T. W. J. Garner, and S. F. Walker. 2009. Global emergence of Batrachochytrium dendrobatidis and amphibian chytridiomycosis in space, time, and host. Annual Review of Microbiology 63:291–310.
- Gascon, C. J., P. Collins, R. D. Moore, D. R. Church, J. E. McKay and J. R. Mendelson III (eds.). 2007. Amphibian Conservation Action Plan. IUCN/SSC Amphibian Specialist Group. Gland, Switzerland, and Cambridge, UK.
- La Marca, E., et al. 2005. Catastrophic population declines and extinctions in Neotropical Harlequin frogs (Bufonidae: Atelopus). Biotropica 37:190–201.
- Lannoo, M. (ed.). 2005. Amphibian Declines: The Conservation Status of United States Species. Berkeley: University of California Press.
- Lannoo, M. 2008. Malformed Frogs: The Collapse of Aquatic Ecosystems. Berkeley: University of California Press.
- Lips, K. R., et al. 2006. Infectious disease and global biodiversity loss: pathogens and enigmatic amphibian extinctions. Proceedings of the National Academy of Science (USA) 103:3165–3170.
- Mendelson, J. R., III, et al. 2006. Policy Forum: Confronting amphibian declines and extinctions. Science 313:48.
- Mendelson, J. R., III, and R. Donnelly. 2011. The Crisis of Global Amphibian Declines: Causes, Consequences, and Solutions. Network for Conservation Educators and Practitioners. New York: American Museum of Natural History. http://research.amnh.org/biodiversity/ncep
- Nichols, D. K. 2003. Tracking down the killer chytrid of amphibians. Herpetological Review 34:101–104.
- Rosenblum, E. B., J. Voyles, T. J. Poorten and J. E. Stajich. 2009. The deadly chytrid fungus: a story of an emerging pathogen. Public Library of Science Pathogens 6:e1000550.
- Skerratt, L. F, et al. 2007. Spread of chytridiomycosis has caused the rapid global decline and extinction of frogs. EcoHealth 4:125–134.
- Stuart, S. N, et al. 2004. Status and trends of amphibian declines and extinctions worldwide. Science 306:1783–1786.
- Voyles, J., et al. 2009. Pathogenesis of chytridiomycosis, a cause of catastrophic amphibian declines. Science 326:582–585.
- Vredenberg, V. T., R. A. Knapp, T. S. Tunstall and C. J. Briggs. 2010. Dynamics of an emerging disease drive large-scale amphibian population extinctions. Proceedings of the National Academy of Sciences (USA). doi/10.1037/pnas.0914111107.
- Whitfield, S. M., et al. 2007. Amphibian and reptile declines over 35 years at La Selva, Costa Rica. Proceedings of the National Academy of Sciences (USA) 104:8352–8356.