Science / Medicine : Saving the Jungle : Scientists are rushing to uncover the biological treasure trove the of the Amazon basin, before it disappears. : Environment: Research on exotic amphibians documents and quantifies the biological wealth of the Amazon basin.
Near midnight, Peter Pearman slogs through the swamp. The water, alive with snakes, nearly reaches the top of his rubber boots, and the miner’s light on his forehead throws a sliver of light into the jungle, catching ghoulish bugs and spiders on their night walks.
Ever so slowly, he stretches out both arms and suddenly slaps his hands together around the leaf of a plant, snatching his prey, a tiny, striped, bulb-eyed frog.
He jots down the species, the time and place in a notebook. This frog is a first-timer, so Pearman carefully removes the tips of two toes with a nail clipper to number the frog, then sets it free. One more statistic in an attempt to unravel the ways of the Amazon.
Pearman, a 30-year-old doctoral student in zoology at Duke University, is completing a four-month study of frog populations near the Hatun Sacha Biological Station at the top of the Amazon River basin in tropical Ecuador.
His work is one of numerous studies under way in Ecuador, Peru, Brazil and other Amazonian countries designed to document and quantify the river basin’s biological wealth.
The results so far have more than substantiated the belief that the Amazon basin, especially near its headwaters in the Andes Mountains, is among the world’s biological treasure troves.
Hatun Sacha, which means Big Forest in the local Quijos Quichua language, was created in 1986 in the tropical forest on the banks of the Napo River, a major Amazon tributary. A private, nonprofit tropical forest research station, it serves as a base for scientists and students from Ecuador and abroad to examine virgin and secondary-growth rain forest on a site covering 625 acres.
The base is a complex of four rough-hewn, open-air cabins with bunk beds on raised wooden floors on a hilltop, with a larger bungalow for meals and research facilities. There is virtually no equipment, not even a refrigerator for specimens. But the virgin forest is an oasis of untouched nature in an area where settlers and loggers have cleared thousands of acres for farming along the river banks.
In its small confines, Hatun Sacha has already registered upwards of 50 new species of plants, said David Neill, an American co-founder of the station from the Missouri Botanical Garden.
“Within a few miles of Hatun Sacha, there are probably half as many plant species as in all of California,” he said. “We have over 200 species of trees per hectare; there are only about 600 species of trees in all of the United States.”
The pioneering frog work at Hatun Sacha was conducted by Harvard University zoologist Gregory Vigle in 1986-87. He found 68 species in just one portion of the station, more than have been found at any other single site in the world.
Those include three new species, including a species of the poison dart frog, which exudes a toxin so poisonous that scientists working with a Colombian variety had to keep the frogs covered so that gases would not build up in the laboratory.
His own study takes the research further, beyond the number of species to the populations of each species, the way they interact and how the frogs relate to their environment.
“The basic question now is why do you find 68 species in 50 hectares (25 acres),” Pearman added. “And for half those species, no one knows where their eggs are, how often they reproduce before they die, how long they live. . . . I’m interested in what variations occur over time in the population, and why. Is it inherent in the population, or the effects of the environment?
“There is a myth that the tropics are very stable, but the lowland tropical forest is really incredibly dynamic,” he said. “Trees are falling, windstorms occur, there are changes in stream beds.”
This emerging understanding of the dynamics of the forest lends support to the argument that the size of nature reserves will have to be much greater to accommodate the range of species and give them adequate habitats, Pearman said. Scientists are attempting to develop data to back this up, part of a newly evolving field called conservation biology.
Most such research is dedicated to larger animal species, such as wild pigs and jaguars that are known to need large habitats, but Pearman reasons that it is far easier to study smaller species, such as frogs, to gauge environmental impact on vertebrates.
“These same techniques also apply to bears and baby seals and all the furry creatures that people want to preserve,” Pearman said.
The Amazon is considered the world’s richest genetic pool, and such research may also provide scientists with irreplaceable material for engineering hybrid plants, natural pesticides and alternative medicines.
Pearman returns to Duke this month after his field study, conducted with a grant of only $2,000, to analyze his date in computer studies. He would like to draw in Ecuadoran students to help in future field work, if he can find the funding.
Red-haired and bearded, Pearman is nocturnal, like his frogs. He ventures out at 8 or 9 p.m., works until 2 or 3 a.m. and sometimes until dawn, catching, marking and very occasionally keeping frogs. Some are finger-sized, others as big as an open hand. Many have spectacularly colorful, intricate markings.
By re-encountering frogs found earlier, Pearman has built up information on their movements, life spans and habits. He sleeps in the heat of the day, and by late afternoon is at a table cataloguing his findings.
He has been stung by a caterpillar, but so far not by any of the many snakes, conga ants, bees, wasps, scorpions and spiders that haunt the jungle, particularly in the watery bogs where the frogs thrive.
“There we are rummaging with our bare hands in the soil. . . . One of these days, I am going to clap my hands together on a plant, and instead of a frog it’s going to be. . . . There’s one caterpillar, if you rub against it, your lymph nodes swell, the whole side of your body goes numb.”
Is he saving the Amazon?
“I’ve come to terms with the fact that studying frogs will not save the rain forests. But to the extent that you can gather data, influence people to think more rigorously, you’ll improve the whole field. So yeah, my work will help. But I wish I could do more.”
