Are Birds Best Hope for Pest-Ridden Coffee Crops?
for National Geographic Magazine
|August 26, 2008|
Chances are you've never heard of Hypothenemus hampei. But this tiny insect is the world's biggest threat to something many of us swear we can't live without: our morning cup of coffee. (See photos.)
The bug, commonly known as the coffee berry borer, strikes almost everywhere coffee grows. It can destroy up to 70 percent of a crop, posing a significant threat to this $70-billion-a-year industry.
Millions of dollars have funded research to eradicate the coffee berry borer, and for decades, coffee farmers the world over have been battling the pest using every weapon they can muster, from traps to insecticide and even other insects—all with limited success.
But a simple solution may already exist in their own backyards: birds.
"By eating the pests that damage coffee crops, birds can provide a valuable service to coffee farmers," said ecologist Matthew Johnson. He's measured birds' protective effects on coffee plants in Jamaica—and concluded that farmers can reap more protection simply by providing the birds a friendlier environment.
Jamaica's mountain regions produce some of the world's best and most expensive varieties of gourmet coffee.
With funding from National Geographic, Johnson, an associate wildlife professor at Humboldt State University in Arcata, California, and his research partner, Jherime Kellermann, showed the extent to which birds protect coffee crops.
The birds target and gobble up insects during the brief window of time before the bugs start doing damage. When foraging birds were free to visit coffee plants, there was up to 14 percent less borer infestation than in plants that were caged off from the birds.
The researchers also found that berry damage was cut nearly in half, providing a significant boost in coffee yields and farm income.
"This is one of those win-win-win situations—something that is good for the farmer, good for the birds, and good for the environment," Johnson said.
A Hot Commodity With a Costly Problem
Coffee is produced in 70 countries, and the industry employs some 20 million farming families around the globe. It's the second most traded commodity in the world, after oil.
The damage caused by the coffee berry borer is commonly put at half a billion dollars a year. But entomologist Fernando E. Vega, an expert on the pest at the U.S. Department of Agriculture, says that's a very conservative estimate, since any hint of crop damage can send the price tumbling.
"As soon as the brokers take a sample and see there is damage by the coffee berry borer, the price goes down immediately," he explained.
So how does a tiny beetle do so much harm? The female borer, just a millimeter and a half long, drills into coffee berries and lays its eggs inside—up to 50 per berry. Once hatched, the young borers devour the beans from within, rendering them worthless.
Solutions aren't easy—or cheap.
Farmers can exhaust up to one-fifth of their annual income attempting to control damage by these pests.
Traps tend not to work, in part because the insects spend so little time outside the coffee berry. Parasitic insects that attack the coffee berry borers aren't always effective or easy to rear.
Researchers, including Vega, are investigating the possibility of fighting the beetles with deadly fungi. In the meantime insecticides, while hardly foolproof, may be the most powerful weapon.
But some farmers find them prohibitively expensive, and the most effective insecticide, endosulfan, is highly toxic—to humans as well as the insects. As a result, endosulfan has already been banned in many countries, and Jamaica's Coffee Industry Board will phase out its use on the island by 2010.
[See related: Pesticides Float From Distant Farms to Protected Forests, Study Says (March 2, 2007)]
Birds, on the other hand, are relatively problem free. Migratory warblers spend every winter in Jamaica and are partial to the coffee berry borers that infest the island's famed Blue Mountain and High Mountain coffee farms.
Johnson estimates that growers who enlist these birds to control berry borers could save as much as $237 an acre (0.4 hectare) every year at lower-elevation farms, where pest infestation is highest. That's more than 20 percent of the average Jamaican coffee farmer's annual income, $1,043 an acre (0.4 hectare) at those elevations.
Johnson hopes his findings will help create an economic incentive for coffee producers to manage their farms in ways that will aid bird conservation—especially by planting or maintaining pockets of trees instead of clear-cutting pastures, as they normally do.
Jamaica's mountain regions, he notes, are at particular risk of deforestation because of clear-cutting for coffee farms. Even if tree maintenance costs some farmers more, he emphasized, "birds are always going to be cheaper than using pesticide"—and more eco-friendly too.
Experts find reason for hope in Johnson's findings, though some caution that there's no silver bullet to eradicate H. hampei.
"The coffee berry borer is an incredibly difficult insect to control, and the only way to make a dent in its population levels in the field is by using an arsenal of strategies," said the USDA's Vega. "The recent findings from Jamaica indicate that birds could be an important part of the arsenal to fight this pest."
Jamaica Stands Behind Bird Arsenal
Johnson's work adds to existing evidence that birds have an overall positive impact on agriculture.
Ornithologist Russell Greenberg, who heads the Smithsonian Migratory Bird Center at the National Zoo in Washington, D.C., conducted a survey of studies examining the effect birds and insects can have on tropical agricultural habitats.
"We found that across all studies, birds reduce all arthropods [which include insects, spiders, and crustaceans] and plant damage," he said.
Although some Jamaican coffee farmers object to planting shade trees for fear of encouraging fungal growth, the island's Coffee Industry Board recently began encouraging farmers to plant trees that support birds.
Peter Williams, a farmer with Kew Park Estate Coffee, which produces Jamaican High Mountain coffee, thinks it's a good idea.
"We have always had an appreciation that birds played a role in controlling [the] coffee borer, but had no idea that the effect was as significant as [Johnson's] research has shown," he wrote in an email. "This is changing the way we farm, as we now are looking at ways to attract more birds to the coffee fields, including preserving more woodland and ensuring that the shade trees are maintained within the coffee fields."
In certain cases, the birds themselves might be able to do some of the work needed to grow more trees in coffee-producing regions. National Geographic grantee Cagan Sekercioglu, an avian ecologist at Stanford University, found that two fruit-eating manakin bird species in Costa Rica serve as effective couriers for seeds. These small, tropical forest dwellers may help increase the number of trees on and around agricultural land, including coffee farms.
In an ongoing radio-tracking project—one of the largest of its kind—Sekercioglu and his team followed up to 500 birds, including a hundred manakins, to learn how they responded to agricultural practices and deforestation.
"Although they prefer forests, we found that these manakins also leave the forest sometimes and travel between fragments," Sekercioglu said. He and his team found that the manakins digest their food very fast—in less than half an hour—and can move several hundred meters in that short time, dispersing seeds across a largely deforested landscape.
Conservation in a Cup
So how can java junkies get their caffeine fix and support pro-bird coffee farming at the same time?
Buying shade-grown coffee, farmed under a forest canopy, can be a good start. Research done a decade ago by Greenberg showed that shade-coffee plantations help bird conservation by providing a nesting habitat that's similar to that of a forest. And fans of shade coffee say its benefits go further than eco-friendliness, since it tastes sweeter than most coffee grown in the sun.
Beyond this, coffee lovers can buy coffee that's marketed as bird friendly.
But some experts warn that eco-marketing terms like these are not interchangeable. "Many people think that shade coffee means bird-friendly coffee," said Stuart Pimm, the chair of conservation ecology at Duke University and a member of National Geographic's Committee for Research and Exploration and Conservation Trust. "Sometimes it is, sometimes it isn't," Pimm said.
In parts of Central America, for example, coffee is grown in the shade of non-native trees that don't attract native birds. "That is shade coffee," Pimm said, "but it's not bird friendly." Neither is shade coffee grown on farms that rely on pesticides.
One reliable option: Look for the Smithsonian Migratory Bird Center's "Bird Friendly" certification.
Organic coffees that bear this trademarked seal of approval are grown under strict ecological standards that require farmers to have three layers of forest cover and at least 11 species of canopy trees, among other conditions, all designed to benefit birdlife. So far, this coffee is being grown on just 35 farms and is available mostly in North America and Japan.
But for coffee lovers who crave their caffeine with an eco-friendly kick, that's one nice way to wake up and smell the java.
|© 1996-2008 National Geographic Society. All rights reserved.|