Houston zoo

Endangered Miss. frogs get a break in the weather

noemail@Houstonzoofrogs.org — Tue, 14 Oct 2008 20:00:00 GMT

By JANET McCONNAUGHEY, Associated Press Writer Sat Oct 11, 1:47 PM ET

NEW ORLEANS - Pick up a Mississippi gopher frog and it covers its eyes with its forefeet, like someone afraid to see what's coming next. And for at least a decade, it's had a good reason not to look.

This year, for a change, nature gave a bit of a break to one of the nation's most endangered species.

The frogs breed only in ponds so shallow they dry up in summer. Hot, dry springs have stranded tadpoles every year since 1998, when 161 froglets hopped out of Glen's Pond in coastal Harrison County, Miss.

The pond held water longer this year. And 181 tadpoles survived a deadly parasite, made it through metamorphosis and headed into the surrounding DeSoto National Forest.

Biologists saved seven generations. They wash some eggs in well water, apparently removing the parasite, hatch them in a lab and put the tadpoles in screen-covered outdoor tanks.

Scientists believe fewer than 100 mature adults live in the wild. Five zoos — in New Orleans, Memphis, Detroit, Miami and Omaha, Neb. — have another 75 frogs.

"Our efforts have managed to stave off likely extinction but there's a long way to go," said Joe Pechmann, an associate professor of biology at Western Carolina University who has studied the frogs since 2002.

Mississippi gopher frogs once lived in longleaf pine forests from western Alabama to southeast Louisiana. Timbering all but eradicated those forests.

Scientists estimate the population from those breeding each year. This year, 50 came to Glen's Pond. Thirty of them were tank-raised; the other 20 had hatched in 2001 and 1998.

Other counts are next to impossible: the frogs live underground, in stump holes and burrows dug by other animals.

They have other oddities. Their breeding call sounds like snoring. And, rather than the smooth backs of many frogs, theirs have bumps which secrete a bitter, milky fluid. Pechmann thinks their "see-no-evil" pose may protect frogs' faces until predators taste the liquid and drops them.

Mississippi gopher frogs face dangers common to all amphibians — predators that eat most of their young, human destruction and pollution of their habitat, and parasites more devastating to amphibians than the Great Plague was to humans.

Scientists estimate that the world has lost up to 170 frog species just in the last decade, and another 1,900 are threatened.

Until 2004, when a much smaller colony was found and a third was created, Glen's Pond was the Mississippi gopher frogs' only known breeding spot.

"People look at temporary ponds and they think there's something wrong with them," either filling them in or digging them deeper for fish ponds or cattle watering holes, Pechmann said. "But the reality is, there's a lot of species such as gopher frogs that depend on temporary ponds; they can't live anywhere else."

The ponds are on ridges, prime development targets. Scientists worry that a housing development near Glen's Pond could keep the U.S. Forest Service from making controlled burns needed by the forest and its animals. But Nathan Watson, senior vice president of development for Tradition Properties Inc., said it is making firebreaks and other provisions to let the burns continue.

No tadpoles survived drought in 1999 or 2000. In 2001, authorities called the National Guard. Crews trucked in water and dug a well from which water was pumped into the pond.

Pechmann first set up tanks in 2002. Since then, scientists have released about 2,000 tank-raised froglets at Glen's Pond and another 3,000 or so at a colony scientists are starting. It's on land owned by The Nature Conservancy, which also owns a 292-tract including the second natural colony.

Researchers used the pump at Glen's Pond in 2005 but only 42 frogs emerged, Pechmann said.

The species' first captive breeding was in March, when in vitro fertilization produced 93 tadpoles at the Memphis Zoo. They all died, apparently from the parasite that kills tadpoles in Glen's Pond. A second lab-fertilized group hatched recently, said Andy Kouba, head of the Memphis zoo's research department.

"We'll probably end up trying to breed them several more times this fall," he said.

Twenty-one egg masses were laid in Glen's Pond this year, and one each in the other two, biologist Mike Sisson said.

Each year's froglets get marked. This year, 480 are in large individual enclosures to learn whether new colonies could make it in less than ideal habitat.

The Audubon Zoo in New Orleans got 36 tadpoles. Sixteen survived.

"They were smaller than a pea when we put them in the tanks," said Nick Hanna, assistant curator for reptiles and amphibians.

The inch-long froglets may grow to 3 1/2 inches.

Any chance of breeding is years away. Males may mature sexually in less than a year, but it can take up to four years for females to become fertile.

The wild froglets alone would nearly triple the wild population if all of them survived.

That won't happen.

"Those little frogs are snack food or finger food for a lot of things in the woods," Sisson said. "The vast majority ... will not make it to adult frog. That's the nature of the business if you're an amphibian."

___

On the Net:

Association of Zoos and Aquariums publication on gopher frogs: http://tinyurl.com/5xh6w9

Audubon Zoo: http://www.auduboninstitute.org

The Memphis Zoo: http://www.memphiszoo.org

14-Oct-08 3:00 PM

Amphibians 'afloat and fighting'

noemail@Houstonzoofrogs.org — Tue, 14 Oct 2008 19:00:00 GMT

Amphibians 'afloat and fighting'

By Richard Black
Environment correspondent, BBC News website, Barcelona

Almost three years ago, I sat in a hotel conference room in Washington DC and heard that it would cost nearly half a billion dollars to save the world's amphibians.

Cheaper than the Iraq invasion, tiny compared to the Wall Street crunch - but a lot of money nevertheless.

Here at the World Conservation Congress are many of the scientists who were present that sunny Washington morning and released their prescription for salvation, the Amphibian Conservation Action Plan.

So three years on, it is time to ask: how are you doing?

First, the money; did it show up?

"It's hard to say, because there have been a lot of other initiatives as well such as Amphibian Ark, which has a lot of facilities," says Claude Gascon, co-chair of the International Union for the Conservation of Nature (IUCN) Amphibian Specialist Group and a senior scientist with Conservation International (CI).

"But from our perspective we've probably had about $10m which has gone directly into tip-of-the-iceberg sites that have been very important for conserving the last of a species."

On firm ground

So this is how last-ditch conservation efforts can work for amphibians.

You go to a region where there is a strong chance that certain species will wink out of existence, and you get your hands on a piece of land where they still live.

In Colombia, a link with two other groups, the American Bird Conservancy and ProAves, enabled the purchase of a 1,100-hectare site. Then, money went in for rangers and a bit of infrastructure and training.

For an initial investment measured in tens of thousands of dollars, the last remnants of a few species can be saved.

In Sri Lanka, the charity struck luck when the government bought patches of forest on an old tea plantation. Any conservation deal has a much higher chance of success when the government and the local community are on board.

Mike Hoffman, another scientist with joint IUCN and CI accreditation, highlights the value of meetings that have brought together expertise from the global and local levels.

"In some of the sessions we've arranged, there's a difference of 50 years between the oldest and youngest people in the group," he says.

"And you can just imagine the information they release, whether the frogs are in a protected area, whether they adapt well or are totally dependent on a pristine forest biome, whether they've been undergoing rapid decline."

Out of the wild

By the time the Amphibian Conservation Summit convened in Washington, the Global Amphibian Assessment had already shown the parlous state of the creatures: one-third were on the threatened species list and 165 species were already believed to be extinct.

An estimated 500 species, it was estimated, could not be conserved in the wild. The only solution was to take them out of their habitat, put them somewhere safe, and wait until conditions returned to something like normal on their home patch.

There are probably as many species waiting to be discovered as we know of now
Claude Gascon, IUCN/CI

This is where Amphibian Ark comes to the fore. A joint initiative between IUCN and the World Association of Zoos and Aquaria (Waza), it numbers many zoos and other institutions that are prepared to give shelter to the endangered animals.

It is not as simple as it might sound. Habitat, moisture, temperature, humidity and prey have to be maintained; water has to be kept free of disease.

It is far from an ideal solution. Recent research demonstrates that some animals lose their robustness and resilience in a captive breeding environment as natural selection stops winnowing, and the range of environmental conditions is constrained.

But with species such as the Wyoming toad (Anaxyrus baxteri), whose natural waters are infested with the lethal fungus Batrachochytrium dendrobatidis, it is at present the only option.

The Atlanta Zoo has even built a portable captive breeding kit facility that can be shipped and used on site.

Golden gone

The chytrid fungus is probably the most serious acute threat to amphibians. In some places, it has basically clear-cut species in a matter of a few years.

It can be cured in captivity; the antibiotic chloramphenicol is one agent that does the trick, and seems to give amphibians some residual protection afterwards. But treating entire water systems in the wild is another matter.

Only discovered a decade ago, chytridiomycosis is still a poorly understood enemy.

"In some patches, we're finding individuals that have survived, whereas with others like the golden toad it does seem to be all over," says Russ Mittermeier, CI's president.

"It seems like salamanders are more resistant, and why should that be? So we still have a long way to go."

The discovery that some species, apparently devastated by chytridiomycosis, have just about hung on is giving some hope.

The Atelopus genus of Central and South America - for whom the Red List reads like a stuck record playing the phrase "Critically Endangered" over and over again - is a case in point.

Are these individuals immune - as some entire species appear to be - or just lucky? Can they rebuild a population?

Human condition

This World Conservation Congress saw the release of another Red List. So how did amphibians fare this time around?

"In the intervening four years, we've had 366 species added to the Red List," says Mike Hoffman, who recently helped co-ordinate Threatened Amphibians of the World, the vast, glossy, information-packed book that CI has just brought out.

"And that's primarily new species just discovered, or ones where the taxonomy has been re-arranged."

This is partly what makes the amphibian world such an exciting one at the moment. Just as species are vanishing, others are appearing to science for the very first time.

"There are now about 6,200 species - that's 10% more than we had five years ago, and that's probably between 50% and 75% of what there is, because a lot of places remain to be explored," says Claude Gascon.

"In Papua, New Guinea and Madagascar, for example, there are probably as many species waiting to be discovered as we know of now."

Making things more complex is the fact that even if chytridiomycosis can be beaten, or if amphibians can evolve their way out of its clutches, myriad other threats are set to persist and grow.

Climate change will raise temperatures and dry wetlands. Other diseases, and pollutants, will spread with increasing human migration.

Hunting continues; above all, so does the relentless spread of the human footprint, turning forests into fields, lakes into building plots and ridges into roads.

Keeping alive all the species we know about, let alone the ones we have yet to discover, is a daunting task, even given the resources that have been mobilised since the launch of the amphibian rescue plan three years ago.

But, says Claude Gascon, we have to try.

"I would argue that the story of amphibians is the story of humans. If we don't get amphibians sorted, the next batch to go extinct may be primates."

Richard.Black-INTERNET@bbc.co.uk

14-Oct-08 2:00 PM

Study: Insecticide decimates tadpoles

noemail@Houstonzoofrogs.org — Wed, 08 Oct 2008 20:00:00 GMT

Study: Insecticide decimates tadpoles

Published: Oct. 6, 2008 at 4:02 PM

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PITTSBURGH, Oct. 6 (UPI) -- A U.S. study suggests the common insecticide malathion can decimate tadpole populations, killing them indirectly at doses too small to kill them directly.

University of Pittsburgh researchers wanted to determine the environmental impact of the use of malathion -- the most popular insecticide in the United States.

The scientists discovered gradual amounts of malathion that were too small to directly kill developing leopard frog tadpoles instead sparked a biological chain of events that deprived them of their primary food source -- bottom dwelling algae, or periphyton, which tadpoles eat.

"As a result, nearly half the tadpoles in the experiment did not reach maturity and would have died in nature," the researchers said.

The results of the National Science Foundation-funded research builds on a nine-year effort by Associate Professor Rick Relyea to determine whether there is a link between pesticides and the global decline in amphibians. Relyea said amphibians are considered an environmental indicator species because of their sensitivity to pollutants and their deaths might foreshadow the poisoning of other, less environmentally sensitive species -- including humans.

Relyea and study co-author Nicole Diecks report their research in the journal Ecological Applications.

8-Oct-08 3:00 PM

Australian researchers discover elusive frog

noemail@Houstonzoofrogs.org — Mon, 22 Sep 2008 15:00:00 GMT

KRISTEN GELINEAU, Associated Press Writer Thu Sep 11, 3:25 AM ET

SYDNEY, Australia - A tiny frog species thought by many experts to be extinct has been rediscovered alive and well in a remote area of Australia's tropical north, researchers said Thursday.

The 1.5 inch-long Armoured Mistfrog had not been seen since 1991, and many experts assumed it had been wiped out by a devastating fungus that struck northern Queensland state.

But two months ago, a doctoral student at James Cook University in Townsville conducting research on another frog species in Queensland stumbled across what appeared to be several Armoured Mistfrogs in a creek, said professor Ross Alford, head of a research team on threatened frogs at the university.

Conrad Hoskin, a researcher at The Australian National University in Canberra who has been studying the evolutionary biology of north Queensland frogs for the past 10 years, conducted DNA tests on tissue samples from the frogs and determined they were the elusive Armoured Mistfrog.

Alford's group got the results on Wednesday. A spokeswoman for the Queensland Environmental Protection Agency also confirmed Hoskin's findings.

"A lot of us were starting to believe it had gone extinct, so to discover it now is amazing," Hoskin said. "It means some of the other species that are missing could potentially just be hidden away along some of the streams up there."

Craig Franklin, a zoology professor at The University of Queensland who studies frogs, said the Mistfrog's rediscovery was exciting.

"It's very significant," Franklin said. "We've lost so many frog species in Australia ... Hopefully it's a population that's making a comeback."

The light brown frogs, with dark brown spots, congregate in areas with fast-flowing water. So far, between 30 and 40 have been found.

The chytrid fungus was blamed for decimating frog populations worldwide, including seven species in Queensland's tropics between the late 1980s and early 1990s.

Armoured Mistfrogs had been classified as critically endangered rather than extinct, but most researchers believed they had died out from the disease, Alford said.

Most of the Armoured Mistfrogs that Alford's group has found are infected with the fungus, but the disease does not appear to be making them sick, he said.

Alford and his team plan to study the creatures to try and determine how they managed to coexist with the fungus, in a bid to aid future conservation and management of vulnerable frogs.

___

On the Net:

James Cook University: http://www.jcu.edu.au/

The Australian National University: http://www.anu.edu.au/index.php

22-Sep-08 10:00 AM

Frog species sprout claws on demand

noemail@Houstonzoofrogs.org — Tue, 24 Jun 2008 14:00:00 GMT

Tue Jun 24, 6:02 AM ET

WASHINGTON (Reuters) - At least 11 species of African frogs carry a built-in concealed weapon -- they can sprout claws on demand to fight off attackers, U.S. researchers reported on Monday.

When threatened, the frogs can puncture their own skin with sharp bones in their toes that they then use to claw their attackers, David Blackburn and colleagues at Harvard University reported.

"It's surprising enough to find a frog with claws," Blackburn, a graduate student, said in a statement.

"The fact that those claws work by cutting through the skin of the frogs' feet is even more astonishing. These are the only vertebrate claws known to pierce their way to functionality."

Blackburn became aware of the frogs when one scratched him in Cameroon.

He looked at museum specimens of 63 African frog species. In 11 central African species the bones at the ends of the toes were pointed and hooked, with smaller, free-floating bones at their tips.

"These nodules are also closely connected to the surrounding skin by dense networks of collagen," Blackburn said. "It appears they hold the skin in place relative to these claw-like bones, such that when the frog flexes a certain muscle in the foot, the sharp bone separates from the nodule and bursts through the skin."

While the finding is new to science, it is not news to locals. "Cameroonian hunters will use long spears or machetes to avoid touching these frogs," Blackburn said. "Some have even reported shooting the frogs."

For their part, the frogs probably use this defense rarely, Blackburn said.

"We suspect, since the frog does suffer a fairly traumatic wound, that they probably use these claws infrequently, and only when threatened," he said.

"Most vertebrates do a much better job of keeping their skeletons inside," he added.

(Reporting by Maggie Fox; Editing by Julie Steenhuysen and Sandra Maler)

24-Jun-08 9:00 AM

World's Amphibians Under Assault

noemail@Houstonzoofrogs.org — Wed, 18 Jun 2008 13:30:00 GMT

The first images that come to mind may be unassuming brown newts or garden-variety green frogs, but amphibians cover a much grander spectrum.

Among about 6,000 species of frogs, salamanders and caecilians (legless animals, pronounced like "Sicilians") are some of the world's most bizarre animals: Giant Chinese salamanders, two meters (6 feet) in length; the "hairy frog" of Cameroon, which not only looks like it sports hair, but also can break its own bones to grow claws (an ability discovered just last month); the Surinam toad, which carries its eggs embedded in its back; and, even more macabre, the Sagalla caecilian, which feeds its own skin to its young.

Amphibians are also among the most colorful animals: The tiny, bright-yellow poison frog (with the spectacular scientific name Phyllobates terriblis) from Colombia, which is, gram for gram, the most poisonous vertebrate in the world; the black-dotted yellow frogs of Panama, which communicate with adorable hand waves; and the charismatic red-eyed tree frogs, aptly nicknamed "swimsuit calendar frogs."

These make up just a small sample of the amazingly diverse amphibians, which have the longest history on earth. They predate all other terrestrial vertebrates.

Yet the first group of animals to colonize the land is also the first that humans are driving off it. Amphibians are disappearing faster than any other animals since the dinosaurs: 32 per cent of all species are threatened with extinction, compared with 23 per cent of mammals and 12 per cent of birds. Almost half are in decline.

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The reasons are complex and vary among species. Some are hunted for the pet trade or, as with the Chinese salamander, for their meat. The destruction of habitat, as with all animals, is a major cause worldwide. Pollution also appears to be a big factor.

One of the most worrisome and headline-grabbing causes is a strange fungus: Batrachochytrium dendrobatidis, a.k.a. chytrid. Nobody quite knows how it kills amphibians - it may smother them, covering the skin they use to absorb oxygen and water, or it might release toxins. Biologists are unanimous in their belief that it is wiping out amphibians across the tropics, in the warm and wet conditions in which they thrive, from Australia to South America. Scientists believe that it is behind the disappearance of 74 species (out of an original 110) of harlequin frog in Central America and at least 10 species of Australian frogs.

Bob Johnson, curator of reptiles and amphibians at the Toronto Zoo, saw one of the fungus' first victims just before it vanished. The golden toad of Costa Rica was once so numerous that tourists would flock to witness their mating season. They were so dense on the forest floor, "we could barely walk, there were so many of them," Johnson says of a trip he made in 1987. Just two years later, they had all disappeared, driven into extinction. "It was just astonishing."

Now, Johnson is caring for one of the last populations of Panama golden frogs, the stars of the most recent David Attenborough BBC documentary, Life in Cold Blood. The frogs were all taken out of the wild before chytrid reached them too.

Humans may be responsible for the spread of the fungus: Scientists suspect that it came from its home in South Africa when clawed frogs were exported 50 years ago for use in pregnancy tests. (A dose of a pregnant woman's urine causes a female clawed frog to lay eggs within eight to 12 hours. The test also works on male frogs, which produce sperm in response to the injection.)

African clawed frogs are mostly resilient to chytrid, and probably carried the fungus, but frogs elsewhere have little defense. It can wipe out a species in a matter of years.

Poster Children

The reason for their vulnerability boils down to two things: They spend part of their lives in water and part on land, so they are exposed to factors in both environments; and their skin - not scaly like a reptile's, but soft, thin and permeable - renders them more sensitive to things such as ultraviolet radiation, pesticides and disease.

As the most threatened group of animals on the planet, they are not just poster children for the biodiversity crisis, they are also harbingers of things to come. Because amphibians occupy a unique and crucial place in the food chain, their extinctions will ripple through the ecosystem and catalyze the rapid disappearance of other animals, large and small.

Their young - salamander larvae and frog tadpoles - are major bottom feeders. When they grow into adults and move onto land, they bring nutrients from the water with them.

"Usually water is a trap for biomass," says McGill University zoologist David Green, one of Canada's foremost authorities on amphibian declines. Things flow from land into water easily in rain, but amphibians, which move back onto land as adults, are one of the very few things in nature that move nutrients in the reverse direction, back onto land. "That's a very important job," says Prof. Green.

Moreover, as adults, they consume huge numbers of insects, then themselves are consumed in huge numbers by larger animals, such as birds and mammals. If we take these middlemen out of the food chain, the consequences could be disastrous. Insect populations could explode, while birds and mammals may disappear.

Yet, despite their importance, conservationists are struggling to raise the funds they need to save them.

"A charismatic bird or mammal will easily draw in money, but it is hard to get funding for amphibians," says Helen Meredith, who is leading the Zoological Society of London's EDGE amphibian-conservation program.

The London Zoo is caring for and breeding a number of spectacular amphibians, including the golden poison frog, and is sponsoring projects overseas for highly endangered amphibians such as the giant Chinese salamander (hunted for its meat in China, where it is considered a delicacy) and the spectacularly ugly purple frog of India, discovered just last year.

EDGE - meaning "evolutionarily distinct and globally endangered" - has found that 85 of the most distinctive and endangered 100 amphibian species are receiving little to no conservation attention. "Amphibians have been pushed into the shadows," says Meredith.

"But in terms of conservation dollars, you can accomplish so much more than investing in any of the large 'charismatic' mammals," says Kevin Zippel, director of Amphibian Ark, a branch of the World Conservation Union, which is supporting captive breeding programs.

Breeding amphibians is comparatively simple. They are small and fairly easy to take care of. "For just $50,000 to $100,000, you can save an entire amphibian species from extinction. Compare that to the amount it costs to rent one panda for a year from China: $1 million, and that doesn't even include housing, food and staff."

Amphibian Ark is trying to raise $50 million for the captive management of 500 species. "If each of the world's largest zoos just took on one species each, we'd be done," says Zippel.

"Though we aren't saying that having these species in glass boxes is an acceptable form of conservation - it's just an option for the future," he adds.

Arks to Tombs

Unless more effort is put into restoring their wild habitats, the "arks will only become tombs," says ecologist Alan Pounds, who has been documenting the decline of golden toads and harlequin frogs in Central America since the 1980s. "We can't save the world with captive breeding. We have always thought that if we have parks and reserves, then we can do what we want with the rest of the planet - and that is not true."

He says the spread of chytrid in the mountains of Costa Rica is tied to global warming. His research, published in the journal Nature, indicates that the fungus causes more frog deaths in warmer years, when the hilltops - normally cool - become more hospitable to the fungus.

It is happening not just in the mountains of Central America: Other researchers have tied the spread of the fungus in midwife toads in Spain to a warming climate.

Chytrid occurs in many places without being lethal. McGill's Prof. Green has found it in about 13 per cent of amphibians from five Canadian provinces. "Canada would have to get warmer and wetter" for the fungus to become lethal, he says. "We may start to see that."

Even if this doesn't happen, frogs all over Canada are disappearing. Leopard frogs on the Prairies are vanishing, and nobody quite knows why. Fowler's toads may be driven out of their only range, in Southern Ontario, where they are mowed over by beach grooming machines sent to remove cigarette butts. Chorus frogs in Quebec, along with their songs, are fading because of suburban development.

The precise causes can be hard to pin down, but many studies have implicated U.V. (ultraviolet) radiation, low doses of pesticides and agricultural pollution. Most ecologists believe that it is rarely one single factor that is responsible, but the combination of threats.

Ecologist Pieter Johnson at the University of Colorado published a landmark study in 2007 in the Proceedings of the National Academy of Sciences (PNAS) demonstrating that the combination of fertilizer runoff in ponds and the flatworm parasite Ribeiroia ondatrae may be responsible for the high prevalence of amphibian mutations that we see all over the United States and Canada (up to 70 per cent of frogs in some wetlands grow multiple arms and legs). High levels of fertilizers in ponds spawn blooms of algae, which in turn foster an explosion in snails which carry the parasites.

Many other studies have found such "synergistic effects." Researchers from Oregon State University have shown that the combination of U.V. radiation and fertilizer pollution kills seven times more frogs than either alone.

Ecologist Rick Relyea at the University of Pittsburgh, who studies pesticides, reported in 2001 in the PNAS that subjecting tadpoles to the fear of a caged predator in their tank, combined with low levels of the pesticide carbaryl, caused grey tree frog tadpoles (found in Canada) to die when neither factor alone killed them. "Many people were shocked and amazed," he says.

He has an upcoming paper in the journal Ecological Applications that will show that combinations of low doses of pesticides - non-lethal on their own - are "highly lethal."

Prof. Relyea cautions that we cannot be sure pesticides are causing frog declines in the wild - more research is needed. "The problem is that an awful lot of effort goes into assessing the benefits of these chemicals, but not the costs." We just need to be smarter about how we use pesticides, he says, such as spraying them in minimal amounts and at times of year when amphibians are less vulnerable - for example, after the tadpoles have grown into frogs.

If pesticides are responsible for deaths in the wild, the impact could be more widespread than we realize. Ecologists from the University of Toronto reported last year that pesticides in the soils in Costa Rica were actually more concentrated higher up the mountains than lower down closer to plantations, carried aloft by breezes and deposited onto the mountaintops when mists form at high elevations.

Chemical cocktails

There is an important lesson to be learned here: Being so sensitive, amphibians are sending us a warning signal. For good reason, they are known as our canaries in the coal mine. "If we lose the amphibians, then we lose our best detection system to see what's going on with the world," says EDGE's Meredith.

Not only that, we also lose "our tools for future drug production," she says. Frogs harbor incredible cocktails of chemicals in their skin that are being investigated by medical researchers. The lethal poisons of arrow frogs may be harnessed for antibiotics, and seem to yield effective painkillers hundreds of times more powerful than morphine. The wood frog, widespread in Canada, can freeze solid and survive, and is being probed for clues to preserve frozen organs during transplant. Salamanders, which can regenerate their limbs, may some day help us to grow lost digits. And it was discovered just three years ago that certain red-eyed tree frogs produce a protein that can block HIV infection.

"On the back of some toad somewhere is the compound that will do wonders for you, but we don't know which one it is yet," says Prof. Green.

Already we have lost amphibian species to extinction that may have been able to help us. In the 1970s, scientists discovered a species of frog in Australia that gestated its eggs in its stomach, using special hormones to shut down its digestive system. It could have held the clues to treat ulcers, but it has not been seen in decades.

Before the 3,000 amphibians in decline suffer the same fate, is there anything we can do? When we are trying to fight the battle on so many fronts, is there any way to win the war?

We need to deal with every single issue at once: climate change, excessive use of agricultural fertilizers and pesticides, depletion of the ozone layer and, above all, habitat degradation.

The case isn't hopeless, says Prof. Green, as long as we take action now. "We have to give amphibians some credit," he says. "They are not so vulnerable and fragile. It's just the combination of factors that they cannot cope with. They are tough as boots if you give them a chance."

Intellpuke: This article was written by Zoe Cormier, a science who lives in London, England. You can read Cormier's article in context here: www.theglobeandmail.com/servlet/story/RTGAM.20080614.wfrogs14/BNStory/Science/home

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18-Jun-08 8:30 AM

There’s much to zoo at the Knoxville Zoo

noemail@Houstonzoofrogs.org — Wed, 18 Jun 2008 13:00:00 GMT

KNOXVILLE – There’s much to zoo at the Knoxville Zoo

In honor of the Association of Zoos and Aquarium’s 2008 Year of the Frog, Knoxville Zoo has introduced “Toadally Frogs” as one of its newest exhibits.

Visitors will have the opportunity to visit a chorus of croakers in this “ribbeting” exhibit. Also new at the zoo is Bloomin’ Butterfly Gardens, where visitors can immerse themselves in a flurry of butterflies floating around the exhibit. Other natural exhibits include The Boyd Family Red Panda Village, Grasslands Africa!, The Stokely African Elephant Preserve, Meerkat Lookout, Penguin Rock, Chimp Ridge, The Pridelands, River Otters, Cheetah Savannah, Gorilla Valley and Black Bear Falls.

18-Jun-08 8:00 AM

Students rally to save frogs

noemail@Houstonzoofrogs.org — Wed, 18 Jun 2008 13:00:00 GMT

Saturday, June 14, 2008

Royal Oak

Students rally to save frogs

They donate money to zoo's conservation center

Shawn D. Lewis / The Detroit News

ROYAL OAK -- Emily Joyce is fond of frogs and hopes to save them from extinction.

Her seventh-grade class at Larson Middle School in Troy recently presented a $500 check to the Detroit Zoo's National Amphibian Conservation Center.

"I really want to help save the frogs because they make the world a better place," said Emily, 13, of Troy.

The Detroit Zoo is part of a worldwide effort to breed certain amphibians in captivity to ensure their future survival. To raise awareness and stave off amphibians' extinction, conservation groups have declared 2008 the Year of the Frog.

Conservationists across the globe are concerned that frogs could face extinction in the next 100 years, due to habitat loss, climate change, pollution and pesticides, and a deadly fungus spread by frogs used for science.

Scientists estimate that one-third to one-half of the world's 6,000 frog, salamander, toad and newt species are threatened, and 120 species have already disappeared. Scientists say frogs are important bellwether species -- meaning the poor health of their populations can signal wider environmental problems. But frogs have also shown promise in medical research: Researchers at Vanderbilt University Medical Center in Nashville tested 15 species, including the northern leopard frog and the bullfrog -- both Michigan natives -- for a substance in their skin that can block viruses.

"Frogs have some secrets in their skin, and they're like a little first-aid kit," said Louise Rollins-Smith, associate professor of microbiology and immunology at Vanderbilt University Medical Center in Nashville, Tenn. Rollins-Smith worked with a team of investigators studying these chemicals and reported in the Journal of Virology that compounds secreted by frog skin are potent blockers of HIV infection. The findings could lead to topical treatments for preventing its transmission.

Judy Armstrong-Hall, a Larson Middle School science teacher who co-sponsored the field trip to the zoo, educates students about the importance of conservation, and the small steps they can take to help.

Her message resonates with her student Mukund Mohan, 12.

"It's important to save the frogs because they eat insects that can carry malaria and other diseases that can destroy humans," he said.

18-Jun-08 8:00 AM

Let's hear three croaks for frogs

noemail@Houstonzoofrogs.org — Wed, 18 Jun 2008 13:00:00 GMT

The amphibians get some love from environmental groups trying to protect them.

By BRENNA MALONEY, Washington Post

Last update: June 13, 2008 - 3:39 PM

What, you didn't know they were in trouble? One-third to one-half of all amphibian species are threatened with extinction, the conservation group Amphibian Ark says. Loss of habitat is the major threat, affecting the most species, but a disease called chytrid fungus is also proving deadly.

Frogs and toads make up one of three main groups of amphibians. There are about 3,500 known species of frogs and 300 kinds of toads. They can be found on every continent except Antarctica.

All toads are frogs, but not all frogs are toads.

Like all amphibians, frogs and toads begin their lives in the water, breathing with gills; as adults on land, they breathe with lungs.

You are most likely to see a toad in your yard or garden; frogs prefer ponds and other still waters. Both animals must return to water to lay their eggs.

"Frogs tend to lay eggs in clumps: a single egg surrounded by other eggs, like a ball of eggs," said Matt Evans, a biologist and herpetologist (an expert in reptiles and amphibians) at the National Zoo in Washington, D.C. "A lot of toads lay their eggs in a single line, so it's like a string of eggs."

A lot can be learned about frogs and toads by observing them. For example, if a toad feels threatened, it will lean forward on its front legs and pump its lungs full of air to appear larger. A frog will tend to flee, using its powerful legs to hop to safety.

Evans reveals a little-known fact about frogs and toads: "They actually use the inside of their eyes to push food down into their throats."

You can see this more clearly in frogs, Evans says: "Frogs have big eyes. You always see a frog blink when it's swallowing. The eye socket goes down into their mouth, so when they swallow, their eyes push down and help push food that's in their mouth back into their throat."

Frogs and toads generally do not use their front legs to grab food or assist them in eating. They have a long, sticky tongue that's hinged at the front of the mouth so it can rapidly flip out and capture insects. And the frog's teeth aren't used for chewing.

"They're bringing a food item in that's alive when it comes to their mouth; they have to swallow it immediately," Evans says.

If you encounter a frog or toad this summer, Evans has some advice.

"It is an age-old myth that toads cause warts. That is not true," he says.

But do beware of frogs and toads, especially if they are secreting toxins.

"If you get it on your hands and rub your eyes, it could cause some stinging and some burning," he says. "I'd say, after you handle them, just wash your hands."

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18-Jun-08 8:00 AM