Clouds in the coffee - coffee plantations as bird habitat

E: The Environmental Magazine, Sept-Oct, 1997 by Chris Wilde

As Habitat Shrinks, a Shade-Grown Harvest Saves Songbirds

Morning commuters, struggling to stay awake and focus on the day's newspaper, probably don't spend a lot of time worrying about where their cup of coffee comes from. They'd be surprised to learn that it was most likely picked by Central American workers earning less than a dollar a day in pesticide-intensive, high-output factory farms. And that these full-sun farms - virtual biological deserts - are swiftly replacing traditional eco-friendly shade farms, which are habitat havens for migrant songbirds.

The close connection between songbirds and shade coffee plantations was first reported by American Museum of Natural History ornithologist Ludlow Griscom in the 1930s. He noted then that coffee growers left much of the natural forest to shade their plants, and that birds and animals were little affected by the rise of the plantations.

Fifty years later, University of California biologist Robert Seib did a landmark study of snake diversity in Guatemalan coffee farms, renewing the connection. A spate of recent studies has also shown a clear link between coffee production and bird biodiversity. The conclusions are unanimous: Traditional shaded farms host high levels of biodiversity, but the new ultraproductive, chemically intensive "full-sun" farms are disasters for wildlife.

Beginning in the 1970s, biologists from the Interamerican Foundation for Tropical Research (FLIT) in Guatemala began surveying migratory songbirds, raptors, bats, reptiles and other fauna in coffee farms. There are about 250 species of birds that breed mainly in the temperate region of North America and winter mainly in the tropics, including waterfowl, shorebirds, raptors and songbirds. As they funnel down through Mexico and the narrow waist of the Central American isthmus, the birds are compressed into spaces much smaller than their breeding area. In 1996, for example, the Mexican conservation group Pronatura Veracruz counted 4.5 million raptors passing over a single town.

Scientists guess that between two and five billion birds make the annual journey. Some take the trip slowly, stopping frequently to rest and refuel, but many go the distance without stopping. The blackpoll warbler, for example, makes an incredible leap from Alaska to the Amazon. The birds have fabulous navigation skills, using landmarks, stars, magnetic fields and other clues to find their way "home," sometimes to the same tree. But all too often the home tree has been replaced by a mall or housing development in the north or a cattle pasture in the south. The disappearance of the forest fits into a deadly mosaic that also includes nest predation by cowbirds, uncontrolled hunting and pesticides.

The coffee/bird connection is about songbirds - warblers, orioles, tanagers, flycatchers, thrushes, vireos and their forest-dependent cohorts. Some are clearly in decline. Others seem to be holding on. But no one doubts that unless current land-use trends are modified, the future of many of these songsters will be bleak.

Every year in Central America, a million acres of tropical forest are destroyed; Mexico suffers a similar loss. The reason that more bird extinctions have not been recorded on some Caribbean islands, according to U.S. Forest Service scientist Joe Wunderle, may be that they found refuge in traditional coffee farms. Wunderle, who studies survival rates of migrant birds, says that such farms are nearly as good as real forest for some species.

That view is echoed by Russell Greenberg and his colleagues at the Smithsonian Migratory Bird Center (SMBC). In Chiapas, Mexico, SMBC biologists found that shaded coffee areas have considerably more birds (at least 150 species) than other agricultural systems and compare favorably with natural forest. The SMBC birders found 94 to 97 percent fewer bird species in sun coffee than in shaded farms.

The importance of coffee as bird habitat is magnified by two crucial conditions. First, coffee is widespread, the most important crop for many areas. It occupies the intermediate altitudes between 1,500 and 4,500 feet, dominating the entire ecosystem. There are an estimated seven million acres of coffee in the northern Neotropics, where most of the migratory birds winter - an area the size of Maryland. In addition, coffee is strategically valuable, often surrounding parks, forming biological corridors between green areas or standing alone, a forested island in a denuded landscape.

John Terborgh, the director of the Duke Center for Tropical Conservation, says the shaded tree farms throw the birds a lifeline. "Virtually throughout the tropics, the belt between 1,500 and 6,000 feet is under siege," he says. "Migrant birds that cannot adapt to artificial conditions, such as dairy farms and coffee plantations, should already be considered endangered."

At least half of the coffee in the region has already been converted to more profitable full sun and is now of no more value to birds and other wildlife than a barren cattle pasture. Even though the market is glutted with low-quality "industrial bulk" coffee from the vast, full-sun fields, many farmers with shaded farms are under tremendous economic pressure to either convert to full sun or sell out to developers. In the late 80s, when coffee prices were down, many producers razed their shaded farms and replaced them with sugar cane, cattle or plastic hothouses for ornamental plants.