Winter’s back has finally broken. Painful memories of sub-zero temperatures are receding as red-winged blackbird and eastern phoebe songs announce the steady march of spring. Yet, far to our south, the majority of songbirds that grace our woodlands and backyards during spring and summer – thrushes, vireos, warblers, tanagers, and orioles – are just beginning to move northward from their wintering grounds in Latin America.
Sipping our early morning cup of coffee as we contemplate the remnant snowpack outside, most of us eagerly await the arrival of these melodic and brightly plumaged songsters. Yet how many of us are aware of the connection between the brew in our cup and the health of migratory bird populations, let alone how our coffee-drinking habits can profoundly impact their conservation?
Many species of neotropical migrants – birds that spend winters south of the United States – have experienced troubling declines over the past two to three decades. Habitat loss and degradation in Central and South America and the Caribbean have put the squeeze on populations of many long-distance migratory birds. Some of our most common and beloved Upper Valley summer residents – such as the wood thrush and rose-breasted grosbeak – are in trouble. Scientists and conservationists are worried.
Want to help in a small but significant way? Drink coffee! Just pay careful attention to the type of coffee you drink.
Coffee is by nature a shade-loving shrub that evolved in the tropical forests of modern-day Ethiopia. Now the second most-traded commodity in the world (after oil), it is the single most important crop for many Latin American and Caribbean countries. For centuries, coffee was grown in these countries under the shaded canopies of native trees, thus simulating a natural forest and supporting a rich diversity of flora and fauna, including migratory birds. Scientists have identified up to 150 species of migrants – including familiar Upper Valley breeders like ruby-throated hummingbirds, black-throated green warblers, American redstarts, and indigo buntings – using shaded coffee plantations in Guatemala and Mexico. These numbers are similar to those found in undisturbed forests.
Many tropical resident birds, such as tinamous, parrots, trogons, toucans, and woodcreepers, also thrive in shade coffee plantations. But birds are only one indicator of shade coffee’s role in protecting biological diversity. Studies of insects, canopy trees, orchids, and amphibians show that shade coffee plantations often serve as critical refuges for forest-dependent species in areas where natural forests have been lost or greatly diminished.
The traditional practice of growing shaded coffee has given way in recent decades to a system of “full-sun” farming, which produces higher yields. Most coffee plantations in Brazil, Colombia and Costa Rica have now been cleared of overstory shade trees. The sun-tolerant coffee varieties come at great ecological cost, causing increased soil erosion and requiring constant doses of chemical fertilizers, pesticides, herbicides, and fungicides. They are not sustainable without intensive management, and individual plants must be replaced much more frequently than the shade varieties.
In addition to these agronomic risks, full-sun coffee production has resulted in major habitat changes for these migratory birds. Plantations are biological deserts compared to their traditional shade counterparts; studies have shown that there are 94-97 percent fewer bird species in sun coffee farms than on shaded farms.
Many coffee farmers in the neotropics would prefer to maintain shade trees on their plantations as their parents and grandparents did, but they are under great political and economic pressure to convert to full-sun farms. Government agencies often subsidize the transition, and coffee prices are largely controlled by fluctuations in production in Brazil and Colombia, leaving farmers at the mercy of international market forces.
As concerned coffee drinkers, nature enthusiasts, and conservationists, we can each make a difference. We need to be aware of the impact of coffee production on tropical forests and wildlife, and we should support Latin American and Caribbean coffee growers who maintain shade trees on their farms, thereby protecting the wintering habitat of North American migrant birds. The Rainforest Alliance, along with a number of other conservation organizations, has developed a process to identify and certify shade-grown coffee that is grown in an environmentally sustainable manner.
As consumers, we can request that local suppliers carry or serve certified shade-grown coffee as an alternative to commercial brands, nearly all of which are grown in full sun. Ask for it! The benefits to the migrant birds that are now winging their way back to the Upper Valley, as well as to a host of other wildlife, tropical forest flora, and local people themselves, will be great. As you sit on your deck in a few weeks sipping coffee while the wood thrushes and scarlet tanagers sing, make sure your brew is shade grown!