Monday, July 13, 2009

This little froggy took a big leap,
This little froggy took a small,
This little froggy leaped sideways,
And this little froggy not at all,
And this little froggy went,
hippity, hippity, hippity hop, all the way home.

In Bengali, the word for mushroom translates literally to Frog's Umbrella. I remember reading books as a child, with pictures of a frog under a mushroom. The pity is that my children may only see frogs in their alphabet books, as most species of frogs are now critically endangered, and many totally extinct.

In 2007, David Attenborough, shooting for the BBC series "Life in Cold Blood" in 2007, visited the last breeding site of the very beautiful and once abundant golden frog in Panama. Fighting time, the scientists studying the golden frog for years waited for the shooting to complete, before removing the last of the golden frogs from the wild and transporting them to a special facility.

A story that appeared in the National Geographic Magazine in April 2009 really moved me. I will paste verbatim an extract from it which made me really sad:
A slender man with a camper's stubble and a soft demeanor squats at the side of pond number 100, bordered by stoic rock walls and edged with pink mountain heather and tangled grasses. Vance Vredenburg is a biologist at San Francisco State University, and he's been studying the mountain yellow-legged frog for 13 years, slumming in a tent on the mountainside for weeks at a time as he monitors 80 different study lakes. Today, mosquito net balled up around his neck, he contemplates ten dead frogs, stiff-legged, white bellies going soft in the sun.

"It wasn't long ago when you walked along the bank of this pond," he recalls, "a frog leapt at every other step. You'd see hundreds of them alive and well, soaking in the sun in a writhing mass." But in 2005, when the biologist hiked up to his camp anticipating another season of long-term studies, "there were dead frogs everywhere. Frogs I'd been working with for years, that I'd tagged and followed through their lives, all dead. I sat down on the ground and cried."

The rest of the article can be read here.

While man has been partially responsible for this mass extinction of amphibians, which are the most ancient of all back-boned animals, by destroying their habitat, the major contribution to this extinction comes from a fungal infection. The fungus called Chytridiomycosis infects the skin of the frogs, hindering their breathing, and choking them to death (frogs breathe through their skins). The fungus is so potent that it has spread to all continents; more than 170 species have already been wiped out by this fungus; more than 1900 species are on the verge of extinction due to this fungus.

The virus first appeared in the African clawed frogs, which have developed a resistance to the fungus due to the presence of anti-biotic producing pro-biotic bacteria in their skin. In the last few decades, the African clawed frog was transported all over the world in large numbers, which could be one of the reasons for this amphibian epidemic. As most frogs around the world had never been exposed to the fungus, thereby having developed no genetic resistance to the fungus, they quickly succumbed to the fungus. Another theory suggests that the fungus suddenly increased in virulence, which the frogs were unable to cope up with. However, the former argument sounds stronger. Carrying species from one continent to another in jet planes has never been a good idea, and we have seen many times in the past the environmental ramifications of such alien introductions.

Government policies worldwide has helped this mass extinction of the amphibians. A few years ago, there was a massive plan to introduce fish into the pristine fish-less upstream waters of rivers. Trouts were introduced into these fish-less waters by dropping from airplanes (incidentally, many of these missed their mark, leaving fish rotting in the forests). This spelt doom for the frogs. Tadpoles are the primary food of trouts, and these tadpoles in these previously fish-less waters had no reason to develop defenses against fishes, and were consequently quickly eaten.

Some conservationist groups are trying to combat the virus (which, in some areas is spreading as quickly as 25 miles a month), by collecting frogs from the wild, and treating them with anti-fungal medicines. Other efforts are aimed at using the bacteria that protects the African clawed frog against the virus in combating the epidemic, but such research may take a while.

Indeed, the future does seem bleak for these amphibians, which are the oldest land-dwelling vertebrates. These amphibians, which saw the dinosaurs come and go, are facing the worst winter of their existence on the planet, and may not see another spring.

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