By Sarah DeWeerdt
Something was rotten in the state of amphibia. Chatting casually in the hallways at the first World Conference of Herpetology in 1989, scientists shared story after story of mysterious declines and disappearances among various species of frogs.
Once, for example, a certain ridge in the Monteverde Cloud Forest of Costa Rica became a riot of psychedelic, flame-orange color for 5 to 10 days each year as the golden toad (Bufo periglenes) congregated to mate. But scientists at the conference said that in 1988, only 10 golden toads were seen, and just a single male showed up in 1989. Other attendees said they had witnessed similarly rapid and dramatic declines among frogs in the rain forests of eastern Australia and the highlands of eastern Brazil.
And this was no common tragedy. Amphibians weren’t just disappearing from places where their habitat was being destroyed or where they were exposed to pollution. They were also vanishing from forest reserves and other pristine habitats far from human disturbance.
No one at the conference presented scientific evidence that amphibians were on the decline, but the sheer number of anecdotes shared in the hallways was worrisome. Could it be true that amphibian species were winking out, one by one, from every corner of the globe? If so, why? Was it something we humans were doing—something less obvious than, say, clearing forests but just as deadly?
Ten years later, we are well on our way to answering some of these questions. The reality of amphibian declines is well accepted in the scientific community and widely reported in the press. Moreover, scientists are making strides in identifying some causes of the declines, most notably with the identification of a new species of fungus that appears to be killing frogs from Australia to Arizona.
A major player in research on disappearing amphibians over the past decade has been the Declining Amphibian Populations Task Force (DAPTF), a volunteer network of more than 3,000 scientists in over 90 countries that operates under the umbrella of the Species Survival Commission (SSC) of the IUCN/World Conservation Union. DAPTF has gathered and disseminated information, sponsored symposia and conferences, and funded research on declining amphibian populations.
In the final analysis, however, DAPTF’s biggest contribution may not be to establish the reality or even the cause of amphibian disappearances but to show that you don’t need a deep purse or a complicated, bureaucratic organization to tackle big scientific problems.
DAPTF was formed in late 1990, after a workshop on declining amphibians sponsored by the U.S. National Research Council was held in Irvine, California. (The workshop, in turn, was a response to concern raised at the World Conference of Herpetology.) There, more than 40 herpetologists from all over the world presented hard data demonstrating the recent declines of many amphibian species.
They also found, however, that information was missing from whole regions of the world—Africa for example—so it was difficult to demonstrate that the declines were a global problem. Moreover, since amphibian populations tend to fluctuate from year to year and because long-term data were scarce, scientists couldn’t be sure whether the declines were part of a normal pattern or real cause for concern.
What the herpetology world needed was a coordinated, global effort to address these issues—to gather background data on amphibians worldwide, to determine which species were declining, and to investigate possible causes.
“I conceived the idea of DAPTF at the Irvine conference,” says David Wake of the University of California at Berkeley, who was one of the conference organizers. “I talked to various people and simply assembled an international group of people who might be interested.” The problem of amphibian declines first came to light in an informal way, and DAPTF developed in a similar fashion, driven by the passion of scientists and the networks between them.
“I was an experienced administrator and simply put together DAPTF in as simple a way as possible,” says Wake. In general, the organization seems to be structured and run according to this straightforward, common-sense approach.
George Rabb, Chair of the SSC, suggested the relationship with SSC. “The situation was beyond the scope of professional disciplinary organizations. . .and had major conservation implications,” he explains. In addition, “two other SSC Specialist Groups with herpetological subjects (on marine turtles and on crocodilians) were making great impacts in conservation,” and the amphibian task force could benefit from their model.
DAPTF headquarters was first established at the Center for Analysis of Environmental Change at Oregon State University in Corvallis and later transferred to The Open University in Milton Keynes, United Kingdom. Forming alliances with established institutions not only decreases the resources required to run DAPTF but also gives the group a broader reach. The SSC, for example, has access to more than 7,000 scientists in 179 countries.
Like the hero of the classic hard-boiled detective story, who typically keeps a spare office with a desk, a chair, and a bare light bulb, DAPTF has adopted a low-overhead strategy to tackle the scientific mystery of amphibian declines. “We have always been exceedingly simple and ‘lean,’ with minimal staff,” says Wake. “We have gone a long way on volunteers and now have been successful in obtaining funding from diverse organizations, none of it ‘big’ funding.”
The real work of DAPTF is done by individual herpetologists organized into Working Groups, which are based either on geography (e.g., Central United States, South Asia) or around specific scientific issues (e.g., determining whether global climate change is involved in amphibian declines). “Our network of Working Groups appears to be unique in that there is no counterpart for any other taxon,” says Tim Halliday, International Director of DAPTF. Each Working Group obtains its own funding and determines its own structure and leadership.
Unlike the hard-boiled detective, who of course is famous for working alone, DAPTF can function only if its members are tightly connected and well informed about each other’s activities and results. This coordinating role is the main purpose of DAPTF headquarters, which consists of an International Director and International Coordinator. An International Board of Directors, currently with 10 members representing six countries, sets research priorities and determines fundraising strategies.
“The trouble with science is that it’s a very slow process,” says Halliday. “In my view the main purpose of DAPTF is to make science work a little faster.” DAPTF headquarters does this in two ways: by encouraging communication and by promoting research on amphibian declines.
To encourage communication among its members, DAPTF publishes a newsletter, Froglog, six times a year. Froglog began as an informal compendium of reports on declining amphibians even before DAPTF was organized. According to Wake, another herpetologist had come up with the name Froglog a couple of years earlier. “I liked the name and used it myself to assemble information—mostly anecdotes—from people around the world and kept it on my office computer.”
Today, the scope of Froglog, which is published both electronically and in hard copy, is somewhat broader. Recent issues have included articles on the status of amphibians in Vietnam, Cuba, Bangladesh, Sri Lanka, New Zealand, Panama, and other countries; a description of an Ecuadorean program to address the issue of declining amphibians; reports on collaborative programs in amphibian conservation, one involving scientists in the United States, Canada, and Mexico, the other in Belize, Guatemala, and Mexico; discussions of the global threats to amphibians including nitrates, ozone depletion, and disease; requests for information, research proposals, and donations; and announcements of upcoming conferences.
Production of the newsletter is the job of Halliday and International Coordinator John Wilkinson, both based at The Open University. The process is typically informal. Many scientists simply send in articles unsolicited; the editors weed out the ones containing results they think should be published in a peer-reviewed format. In addition, says Halliday, “I solicit quite a lot of articles, typically when I hear and talk to people at meetings.” He considers the newsletter, widely praised in the herpetological community, one of the Task Force’s main successes.
Another way of promoting communication is by bringing people together face to face. DAPTF has organized a symposium at every World Conference of Herpetology (except the first). The Task Force also recently helped organize a series of workshops in Mexico, Panama, and Ecuador that involved 88 people from 13 countries all together. “Probably we make the biggest difference in the developing world,” says Halliday, where scientists have access to fewer resources and less institutional support.
To promote research on amphibian declines, DAPTF gives Seed Grants, onetime awards of $500 to $2,000 on topics identified by the Board of Directors, such as the effects of global climate change and UV-B radiation on amphibians.
“Our Seed Grant program has been a huge success,” says Halliday. So far, 44 grants totaling $92,000 have been given to researchers all over the world. “On average, each grant awarded has yielded one or two publications in recognized journals, and on average, the grant holder has turned each $1 given by DAPTF into $20 from other sources.”
The Seed Grant that Halliday calls “probably the biggest individual success” of the program helped Southern Illinois University researcher Karen Lips study frogs in Panama’s Reserva Forestal Fortuna. In 1996-97, Lips found several streams with no frogs at all and others that had lost half their frog species since she’d surveyed the area a few years before. She also found a number of dead and dying frogs, a rare sight because such frogs tend to be snapped up quickly by predators and scavengers. The dying frogs trembled or convulsed, and many of the dead frogs seemed “frozen” in their nightly calling positions, as if they had died very quickly. All of this suggested that a great many frogs at Fortuna were dying rapidly; this, in turn, was evidence of a disease epidemic.
Similar evidence was being uncovered on the east coast of Australia, where 14 species of frogs had declined sharply or had become extinct since the 1970s. The declines had happened very rapidly over the course of just a few years for each species. Moreover, scientists had traced the geographic spread of the die-offs from population to population, a directional pattern typical of an epidemic.
Later in 1997, DAPTF helped organize a workshop at the University of Illinois, where researchers established that both the Australian and the Panamanian frogs had been killed by disease—a fungus later dubbed Batrachochytrium dendrobatidis. Related species of fungi, known collectively as chytrids, are important pathogens of algae, insects, and other groups but had never before been known to infect vertebrates. B. dendrobatidis apparently feeds off the keratin of amphibians’ skin.
The fungus was soon confirmed as the cause of more than a dozen frog die-offs in eastern Australia and 10 in Panama. It has also been implicated in recent frog population declines in southwest Australia, Costa Rica, Spain, Africa, and Arizona, and California. Scientists have even found evidence, from preserved specimens, that it may have been involved in die-offs in the U.S. and Australia during the 1970s and 1980s (some of the very die-offs that first raised the alarm about declining amphibians). Many herpetologists now believe that the chytrid is the major factor behind amphibian declines in Australia and the Americas.
No one thinks the fungus explains all amphibian declines. And most herpetologists agree that local habitat destruction is the biggest threat facing amphibians today. Still, the news was exciting because this was the first time scientists had found evidence of a causal factor that could explain amphibian declines as a global phenomenon.
Halliday is reluctant to suggest DAPTF deserves credit for this success. “I have no doubt that if DAPTF did not exist, much of the research into declining amphibian populations of recent years would have been done anyway,” he says. “DAPTF does provide an international focus for all this research, but the value of that is hard to assess.” All along, DAPTF has been more interested in encouraging and guiding research than in controlling or dictating it, and that makes the group’s impact and success difficult to evaluate.
DAPTF’s non-traditional structure and approach has raised other challenges. “In the rather odd context of scientific evaluation that currently exists in the U.S. and the U.K., running something like DAPTF is not regarded as ‘real research’,” says Halliday. Those who coordinate the network may face pressure because they “cannot enrich the research reputations of our institutions by publishing in the high impact journals or by pulling in big grants from the usual sources.”
Nevertheless, DAPTF is forging ahead with an approach that challenges traditional academic boundaries and assumptions. A new initiative, headed by ecologist Jim Collins of Arizona State University, involves 24 scientists from diverse fields who will explore the role of host-pathogen relationships in amphibian declines. DAPTF helped secure funding from the U.S. National Science Foundation for the program. It is hoped that this interdisciplinary approach will answer some of the remaining questions about the chytrid fungus and help scientists understand why the disease has emerged so suddenly and so virulently in widely scattered locations. It may even help scientists and managers take a long-hoped-for next step: figuring out how to stop or prevent amphibians from disappearing.
Sarah DeWeerdt is a freelance writer in Seattle, Washington.
For more information:
DAPTF web site http://ice.ucdavis.edu/project/daptf
Amphibia Web elib.cs.berkeley.edu/aw
