What I Don't Know Yet

Twilight of the Frogs

Rescuers race to save Central American frogs –

Fungus puts species at risk of extinction

Blade, The (Toledo, OH) – Sunday, August 6, 2006

Author: JENNI LAIDMAN BLADE SCIENCE WRITER
First of two parts 

EL VALLE DE ANTON, Panama – Kent Bekker of the Toledo Zoo starts his day swinging a makeshift net across damp grass. It’s about 8:30 in the morning, and already, the air is near liquid with humidity.

One doesn’t so much move through the day as swim through it. Nothing dries out. Skin glistens with sweat even when the evening’s mountain breezes make light jackets necessary. Car interiors smell of mildew. An abandoned damp towel sprouts a carpet of mold. A climate that allows a gardener’s dream of lush flowers is the perfect breeding ground for fungi.

It is also the ideal home for a fungus few here have heard of. It’s called chytrid (KIT-rid), or formally Batrachochytrium dendrobatidis, and it’s completing a deadly sweep through Central America. It threatens to kill nearly all of Panama’s frogs, as it has in Costa Rica and Mexico before this, and as it is doing on every continent on the planet. It’s why the Toledo Zoo sent Mr. Bekker to Panama. He’s part of a team attempting an unprecedented feat: the rescue of dozens of frog species from extinction.

Mr. Bekker snaps his net through the air as though it were a flag, hoping to dry it out just a bit. It’s a cloth bag, and it sticks to itself. He looks in the plastic cup humming with the insects he’s collected so far. There are not enough to feed all the frogs.

Why, he wonders, didn’t someone explain that the project needed insect nets? He and Richter Tipton, a volunteer from Baltimore, spent their spare moments during their first week in El Valle trying to invent better ways to collect insects. On the reject pile are various insect trap designs, including some that used lights inside of bottles. They seemed like good ideas. But even a pillowcase on a stick works better.

Silence of the frogs

Finding enough frog food, it turns out, is just another crisis, faced like any other critical chore in an unusual project where a mistake could contribute to the extinction of a species.

Mr. Bekker collects bugs behind the Hotel Campestre, which, despite ongoing renovation, has the dark look of a haunted inn. A second two-story building presents a far cheerier prospect. In two rooms at its farthest end, out of sight of the few guests who find their way here now during the rainy season, some 200 frogs make their last stand.

These 200 will be joined by many more in the coming weeks, as volunteers attempt to rescue species threatened with immediate extinction. They have only a few months in which to work. By January, it will be too late. The chytrid fungus will have done its work here. The forests and streams will be silent.

Julie Ray knows that silence. Ms. Ray, a doctoral candidate at Old Dominion University in Virginia, is in El Valle to research snakes. But eight months ago she was in El Cope, about 30 miles west of here, after the chytrid fungus swept through.

“It was almost eerie because we were there at night and didn’t hear a thing,” she said.

Already, the disappearance of frogs is damaging the rest of the ecosystem. Without frogs to eat, the snakes are relying on lizards, now also in decline because of predation, said Chad Montgomery, a herpetologist who’s studied the impact of frog disappearance on the ecosystem. Snakes, too, are disappearing.

“Because the tadpoles have died, nothing is grazing on the algae,” Ms. Ray said. Stream rocks are slick with the growth tadpoles once eliminated.

The consequences continue to play out. Where it will end is anyone’s guess. Will it affect birds? Aquatic invertebrates? Insects? Mammals? Maybe, the experts say. Probably.

Already, chytrid has killed thousands of amphibians in Australia. It is killing frogs, toads, and salamanders in Africa, in Europe, in North and South America, and in Asia. Amphibians were already in crisis the world over from habitat destruction and pesticide use. Now they face an enemy perhaps more intractable.

“It’s probably the most significant conservation issue that zoos have ever dealt with,” said Robert Lacy, chairman of the Conservation Breeding Specialist Group of the World Conservation Union, the organization attempting to coordinate numerous amphibian rescue programs.

“We used to call it a decline, but it’s really amphibian species extinction that we’re facing,” the Waterville resident said.

Where the chytrid fungus came from, why it arose now, and how devastating it will ultimately be to the world’s already declining amphibian diversity isn’t certain, but in this lush and humid crater of an ancient volcano known as El Valle, some two hours west of Panama’s capital, amphibian experts are hoping to create an ark of sorts for any frogs they can save.

The problem is, there may be no Mount Ararat on the horizon for this ark. It’s possible these animals will never be able to leave captivity. It’s not known how long chytrid remains in the environment. And rescues like this may be needed again and again.

“What we’re looking at is near categorical extinction,” said Joe Mendelson, the herpetology curator for Zoo Atlanta, who helps with the El Valle effort.

“An entire section of vertebrates are losing a massive chunk of itself. That’s never happened before in human history. The last time something like that happened on anything near that scale was dinosaurs,” Mr. Mendelson said. “And that changed the direction of the planet.”

Vanishing species

Already species have vanished for good, perhaps as many 122 since 1980. Two species of frogs known for their unique reproductive habits, the gastric brooding frogs of Australia, haven’t been seen since the 1980s. The female of these species would gobble her eggs and coddle them in her tummy until, like the cursed girl in the fairy tale, she opened her mouth and frogs hopped out.

Costa Rica’s golden toad disappeared before anyone thought to collect a single specimen. A harlequin frog now extinct in Costa Rica wasn’t even recognized as a distinct species until every member vanished.

The Wyoming toad in the United States is another chytrid victim. They’re considered extinct in the wild, although they are kept in many zoos, including Toledo’s, which is a leader in efforts to save this toad.

Even more sobering than these losses is the belief that amphibians are simply the first group of organism to face widespread extinction threats. All wildlife may soon follow.

“Biodiversity is under terrific pressure,” said James Collins, head of biological services for the National Science Foundation and a leader in the issue of declining amphibian diversity.

“It’s only going to get worse,” he said.

While we’ve long preserved natural treasures by creating parks and preserves, today’s attackers respect no boundaries. Emerging infectious diseases such as chytrid fungus breach those preserves. Global climate change makes mockery of that protection. Exotic species and contaminants easily pass through the gates.

“We need to rethink what it means to talk about conservation,” Mr. Collins said. “Business as usual probably isn’t going to do it.”

Insect motel

Kent Bekker’s concerns are far more immediate. How do you feed 200 frogs when you don’t even know what they eat?

With luck and effort, this daily hunt for food may abate soon. By the time the frogs move to a permanent facility on the grounds of El Nispero Zoo in El Valle, it has to end. It’s too fragile a link on which to suspend the future of amphibians.

To that end, one of the two frog hotel rooms also serves as an insect incubator. Beetles reproduce in a pan of flour on the bathroom floor. Makeshift cricket nurseries, fly hatcheries, sow-bug birthing suites, and cockroach lying-in chambers line nearby shelves. Will these bugs reproduce successfully? Will there be enough critters born in these cultures to eliminate the daily bug-catching forays, Mr. Bekker wonders. No one knows. This is a new ball game.

You can’t call the pet supplier and order more bugs. There are no such suppliers in Panama. You can’t import termites or crickets from suppliers in the United States without running the risk of releasing a destructive invasive species. It would have been great if the bugs had been captured and reproducing before the frog rescue began. It would have been great if the rescued frogs didn’t have to live in hotel rooms. But there was no time.

Chytrid caught researchers and conservation experts with a plan but still not quite prepared.

Death of a symbol

Finding dead frogs is unusual. Nature disposes of the bodies quickly. Parasites, insects, and bacteria feast on the rapidly deteriorating carcasses, and they vanish.

So when Edgardo Griffith began finding dead frogs a dozen or so miles from El Valle in January, he was worried. Mr. Griffith is the Panamanian biologist who runs the frog rescue project, under the direction of the Houston Zoo.

The dead animals were golden frogs, a glowing tangerine-colored jewel of a frog decorated with black spots. Golden frogs, revered since pre-Colombian times, are startling beauties, and possess a unique communication strategy. They hear through the vibrations of sound waves on their skin, and they supplement the cheerful “peeps” they make to prospective mates with what researchers call “semaphore,” waving their legs to signal other frogs.

They are a national symbol. Tourist markets are rife with their image. There are golden frog T-shirts, golden frog handbags, golden frogs painted on feathers, and golden frog jewelry. There is even a wide selection of ashtrays in which clay golden frogs lounge, sometimes smoking a cigarette. The frog’s popularity is as much a curse as a blessing since it subjects them to overcollection by those who want the animal as a talisman.

Around El Valle, golden frogs are just one part of the rich amphibian diversity that includes some 70 to 90 different amphibian species. If the dead frog Mr. Griffith found is a victim of chytrid, the diversity will crumble in months.

Mr. Griffith sent the golden frog carcasses to be checked for chytrid and held his breath. The tests were negative. The plague had not yet reached the area.

Chytrid fungus seems to be traveling in a wave across Central America, but the wave had yet to crest in this part of Panama. Unfortunately, it was about to. That first laboratory analysis was wrong.

A step ahead of death

Karen Lips has tracked the chytrid wave since the early 1990s, when she stumbled into its path as a researcher pursuing her doctorate. She was studying a tree frog with the musical name of Hyla calypsa, or, less poetically, the spiney green tree frog, in a mountain reserve at the eastern edge of Costa Rica, not far from the Panamanian border. Over the span of her research, the frogs she was studying, and every other frog in the area, disappeared.

“My career morphed into amphibian decline research,” she said.

Today, she is a leader in the field, her work cited everywhere. But in the face of the first die-off she witnessed, she could only wonder: Was this extinction related to a famous die-off of golden toads on the other end of Costa Rica in the late 1980s? Was this thing, whatever it was, moving east?

She picked a new study site farther east at Fortuna, Panama. By December, 1996, she was finding dead frogs there. By the following summer, she could find only six amphibians.

She moved east again to El Cope, with the expectation that the plague would follow. In the meantime, researchers finally identified the killer she was seeing as a fungus. The El Cope research team found its first dead frog in October, 2004. By January, 2005, the population crashed.

She never saw another Hyla calypsa again. The frog no bigger than a thumb, a 28th of an ounce, has vanished.

Without question, El Valle would be next.

But before the fungus arrived, the world conservation community hoped to quickly build an ark.

The Houston Zoo, leading a loose-knit consortium of zoos and conservation groups from around the world, began construction of a 2,400-square-foot, $45,000 El Valle Amphibian Conservation Center – the EVACC, for short – at the El Nispero Zoo in El Valle.

Upon EVACC’s completion, rescue teams would swoop into the Central American nation and move as many amphibians as practical into the new center.

Unprepared ark

In May, Mr. Griffith found the first frog to test positive for chytrid in the El Valle area.

This was too soon. The ark was not finished – nowhere near it. Construction had been delayed by a lengthy permitting process.

But there was no time to wait. Hotel rooms would have to suffice. A call for help went out to zoos and conservation groups all over the world.

Two weeks later, by the first week of June, the first team of frog rescuers arrived. They swept into the nearby cloud forests and began collecting frogs.

David Wake, an emeritus professor at the University of California at Berkeley, has been a leader in addressing the worldwide loss of amphibians since the 1980s. He views the frog rescue in Panama as a necessary but deeply disturbing action.

“It’s almost a panic,” he said. “What can we do? We can’t do anything else but take them and try to raise them. It’s very upsetting. It’s upsetting that we feel like we’re at that stage. It just shows they’re at the end of their rope. I just hate to think of it.”

The crisis requires such measures, he said.

“I know of nothing like this” he continued. “This is an unparalleled time. [Amphibians are an] organism that have been on this planet for well over 100 million years. To think that they’re checking out on our watch,” Mr. Wake said.

“The dinosaurs were big and impressive, but what we forget is the frogs were there. They were there with the dinosaurs. … and now 70 million years later, they’re taking it. It’s pretty shocking. It’s pretty hard to accept.”

FUNGUS EFFECTS VARY IN U.S.

Most amphibians in the United States already have been exposed to chytrid fungus, but the effect on animal populations seems to vary with geography.

“Chytrid is in Ohio,” said Kevin Zippel, amphibian program officer for the Conservation Breeding Specialist Group of the World Conservation Union.

Mr. Zippel said the Detroit Zoo, where he worked for five years, put Ohio-caught cricket frogs into a mixed species display. The frogs died from chytrid fungal infections. The animals apparently brought the disease with them from the wild, he said.

It took the stress of captivity to make it lethal. In 1999, there was no quick test for chytrid fungus nor was there a treatment.

Today, chytrid is easy to test for and can be treated in captivity by soaking the animal in an anti-fungal medication.

Tests of preserved frogs in museum collections reveal that North American frogs and toads have carried the disease since at least 1961. Some researchers speculate that the fungus may have done its worst work in the 1970s.

Mountain amphibian populations seem most vulnerable. The Wyoming toad, now extinct in the wild, and frogs and salamanders in the mountains of Arizona and New Mexico have been hard hit.

Climate may play a role in how chytrid affects local populations. The fungus dies at temperatures above 99 degrees Fahrenheit and does best between 59 and 73 Fahrenheit.

“It’s not as active in the summer when it’s hot,” Mr. Zippel said.

Some amphibians are naturally resistant to the lethal effects of chytrid. Bullfrogs, for instance, don’t seem to succumb to the disease. Such animals can act as carriers, infecting less-resistant populations.

– Jenni Laidman

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