The Great Apes Edge Toward Extinction
The finding was bad enough: During the last two decades, the population of wild chimpanzees and gorillas in the West African nations of Gabon and the Republic of the Congo has declined by more than half. But it was the context that made the news so discouraging. The dense forests in the two nations harbor an estimated 80 percent of the world’s remaining great apes, whose numbers have plunged elsewhere in Africa as human populations have expanded.
What’s more, scientists and conservationists have been active in the area for many years. “The fact that all of this could go on before our eyes and we didn’t see it happening is the really scary thing,” says Lee White, a Wildlife Conservation Society ecologist and coauthor of a study published in April that sounds a dire warning. Without aggressive intervention, wild chimps and gorillas could be pushed to the brink of extinction in just one decade.
Gabon and the Republic of the Congo were once thought to be safe havens for the great apes because the forest habitats in both countries remain largely intact. But a research team led by ecologist Peter Walsh of Princeton University discovered that conservation efforts are no match for two stealth threats: hunting and the Ebola virus.
Logging has been limited to selective thinning of forestland, but the roads built to accommodate mechanized equipment have provided organized groups of hunters with easier access to the apes and helped support a growing and illegal trade in “bush meat.” Meanwhile, Ebola outbreaks are decimating gorillas in the remote regions where their density is greatest. Researchers believe that sporadic Ebola outbreaks in Gabon have killed thousands of gorillas—perhaps as many as 9,000 between 1992 and 2000.
No one knows if more outbreaks are occurring now than in the past or if more gorillas are dying during each outbreak. At present, the hot zone is in the northwest Republic of the Congo, where White says Ebola is advancing “like a weather front” on the border of Odzala National Park, a 3,475-square-mile wildlife preserve that is home to about 50,000 gorillas.
The research team called for the status of wild chimps and gorillas to be raised to “critically endangered” and for foreign governments to link aid to verifiable efforts to stop hunting and the traffic in bush meat. White is also hopeful that a new Ebola vaccine developed under the auspices of the National Institutes of Health (see “Fast-Acting Ebola Vaccine Tested,” page 61) will prove useful in containing outbreaks among gorillas.
Bizarre Bacterium Dines on Toxic Waste
The soil behind the abandoned dry cleaners in Oscoda, Michigan, was saturated with chlorinated solvents that had been routinely dumped there for decades. The poisons had penetrated the water table and spread to Lake Huron, 150 yards away. When environmental engineer Frank Löffler visited the site, he discovered that microbes 20 feet underground appeared to be feasting on the toxic waste.
So he took some soil samples back to the lab and spent the next seven years studying the bizarre creatures from the deep. Finally, in July, Löffler announced that he and his colleagues at the Georgia Institute of Technology had isolated a previously unidentified bacterium—BAV1—that thrives on vinyl chloride, a carcinogen produced when the solvents in dry-cleaning fluids and metal cleaners break down.
Löffler also reported that he had unleashed the bacterium in a test pit at the Oscoda site and “it completely cleaned the site of contaminants in just six weeks.” With vinyl chloride present in one-third of the toxic waste sites the Environmental Protection Agency lists as high priorities for cleanup, BAV1 will be well fed for years to come.
—Michael W. Robbins
Deadly Extremes: The Weather Outside Was Frightful
Too hot, too cold, too wet, too windy, too dry. The weather in 2003 was often just too much. Kenneth Davidson of the World Meteorological Organization says the year may set a record for meteorological records. In late spring, the whole planet sweltered: Average land temperature for May was the highest in recorded history.
June was the hottest in at least 250 years in Switzerland, and southern France topped 104 degrees Fahrenheit—some 10 degrees above average. Indeed, the heat wave in France—a country that often gets by without air-conditioning—didn’t abate until the end of August, by which time more than 20,000 people had died. Meanwhile, heat waves in India were pushing the mercury to as much as 120°F, claiming at least 1,400 lives.
Bad weather battered as well as baked. In May a tropical cyclone drenched an already wet Sri Lanka, causing floods and landslides that killed 300. Also in May the United States was whipped by 562 tornadoes—topping the previous single-month record, set in June 1992, by more than 40 percent. In the American South, farmers reeled from one extreme to the other.
“After two years of drought and tremendous loss of crops, this year they’re losing crops because it’s too wet,” says Davidson. And in the Southern Hemisphere, a cold front of historic proportions hit South Africa on August 21 when the mercury in some areas sank as low as 13°F.
Affixing blame is nearly impossible with something as complex and capricious as the weather. Still, Davidson says, “Man’s influence is clear: We’ve increased the amount of greenhouse gases in the atmosphere, and that’s exacerbating the warming trend we’re already in.”
Global Warming Triggers Genetic Change in Red Squirrels
Scientists have studied evolutionary changes since Charles Darwin set sail on HMS Beagle. But rarely have they watched one take place before their eyes. In March a team of biologists led by Stan Boutin of the University of Alberta reported a shift in the gene pool of North American red squirrels, one that can be placed squarely at the door of higher temperatures.
In the Kluane Lake region of Canada’s Yukon Territory, the team discovered that more and more female squirrels, who are able to breed only one day during the year, were mating, on average, 18 days earlier than they were a decade ago. It seems higher temperatures in the region, up 3.6 degrees Fahrenheit in the last 25 years, means spruce trees produce more cones—the squirrel’s main food—throughout the summer.
As a result, the squirrels stash more food for the winter. Come spring, they have more energy to reproduce, Boutin says. The shift, he adds, is increasingly dramatic. With each new generation, there are fewer who wait to breed.
The team made its discovery after tagging more than 5,000 squirrels and watching their movements for 10 years. They borrowed an analytical technique used in agricultural breeding (but never before applied to the study of wild populations) to determine that squirrel babies born earlier in the spring thrive and reproduce at a higher rate than squirrels born later.
Now Boutin and his colleagues have begun a three-to-five-year experiment in which they will further enhance the food supply of a group of squirrels “to see whether the timing of reproduction continues to advance.”
—Michael W. Robbins