July 28, 2010
I think it’s time we had a talk about the birds and the bees. Over coffee, naturally.
No, really. Did you know that the shady forests where coffee is traditionally grown in Latin America provide a critical habitat for many migratory birds? Smithsonian Migratory Bird Center has an informative slide show about this on the National Zoo’s website.
According to the SMBC, “of all agricultural systems in the tropics, shade coffee plantations have been found to have some of the highest numbers of individuals and species of migratory birds.” The hundreds of species attracted to such forests include everything from hawks to hummingbirds—and yes, even a stork or two.
However, in the past two or three decades, many coffee growers have latched onto new “technified” varieties which can thrive in direct sunlight, making planting and harvesting more efficient. Such “sun coffee” is often cheaper and more reliable to produce than “shade coffee“—and has been encouraged in the name of international development—but it comes at an environmental cost. Not only does sun coffee require more pesticides and fungicides, but it creates an incentive to clear land, raising the risk of erosion and reducing the habitat available to birds, bats and other wildlife. (And some experts say it doesn’t taste as good as shade-grown coffee.)
The SMBC cautions:
The diversity of migratory birds plummets when coffee is converted from shade to sun…Studies in Colombia and Mexico found 94-97% fewer bird species in sun-grown coffee than in shade-grown coffee.
Shade-coffee farms also support native bee populations and help maintain biodiversity, according to a study published this week in the Proceedings of the National Academy of Sciences. It’s based on a 1,200-hectare landscape in the Soconusco region of Chiapas, Mexico, where coffee “is cultivated in the traditional style, under a canopy of overstory trees.”
By observing pollination patterns and analyzing the DNA of the resulting seeds in a particular type of tree called a saquiyac (Miconia affinis), the researchers found that the bees helped to spread a mix of genes between saquiyacs in different parts of the often-fragmented landscape—or in other words, prevented inbreeding, which is a bad idea for trees as well as humans. The bees traveled twice as far in shade-coffee habitat as they did in other nearby forest, with some flying more than a mile to deliver pollen.
Non-native honeybees would not be able to do that, because saquiyacs have a particular preference for “sonication.” That means that the trees’ reproductive organs won’t release pollen unless the bee grasps them and vibrates in just the right way. (I’m not making this up, honest!) It’s also called buzz pollination, and only occurs in certain bee species, which in the case of this study included natives like carpenter bees and stingless Trigona.
The authors conclude that the relationship between shade-grown coffee, native bees and trees is a mutually beneficial love triangle:
Traditional shade coffee farms can maintain native insect communities…Native bee communities within shade coffee farms…not only ensure against the loss of introduced honey bees and increase coffee yields, but maintain the reproduction and genetic diversity of native trees.
So the next time I shop for coffee, I’ll seek out shade-grown beans, like the ones featured in this directory. (Bonus points if the coffee is also Fair Trade, a certification which typically takes into account both labor and environmental practices.)
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