The Chocolate Tree

January 1, 2003 by Robert Rice and Russell Greenberg

Bellbird in tropical forest

To most North Americans the word "chocolate" probably conjures visions of a fragrant, nut-studded brown slab, or a box full of small but elaborate variations on gooeyness, or one of those outrageous dark desserts with names such as "mud pie" or "death by chocolate."

Few of us who savor and consume such delights think about moist, lush foliage, the shrieks of toucans and parrots, or a Maya ruler from the seventh century A.C. sipping chili-spiked cocoa froth.

But perhaps we should.

In 1996, ornithologists announced the discovery of a new specis of Neotropical ovenbird, the pink-legged graveteiro (Acrobatornis fonsecai), within the rustic cacao farms of the state of Bahia, Brazil. An endangered monkey, the golden-headed lion tamarin, had already been spotted in the same habitat.

Those sightings were turning points for conservation biologists. After decades of focusing on pristine habitats, the biologists began to pay increasing attention to agricultural settings. Part of the shift came from their realization that in many areas, agroforests and forest fragments are all that remain of the original, vast forestlands. Cacao farms quickly came to be regarded as preservers of biodiversity.

For the past decade, those of us at the Smithsonian Migratory Bird Center have been surveying the compostition and diversity of birds in southeastern Mexico, both in natural and human-created systems. Two quite different kinds of cacao farm are included in the survey.

The first are small, rustic farms in a "buffer zone"—a belt of well-forested but still partly cultivated land—surrounding the completely uncultivated 1,300 square mile Montes Azules Biosphere Reserve in the Selva Lacandona, a huge lowland tropical forest in the Mexican state of Chiapas.

The second are small, polycultural, planted-shade farms in the lowlands of the state of Tabasco, on the coast of the Gulf of Mexico.

The diversity of bird species we measured on the Selva Lacandona farms is more similar to what it is in pristine forests, or at least in forests that have been only slightly altered from their pristine state.

Moreover, that diversity is between one and a half and seven times as great as it is in pastoral, open, or other more traditional agricultural habitats. A quarter of the most common species—mostly forest-breeding birds, both resident and migratory—occur both in the Lacandona agroforest and in undisturbed tropical forest.

In contrast, unfortunately, Tabasco's polycultural farms support substantially fewer bird species than do the rustic farms—84 compared with 142. We found virtually no forest-breeding species on the polycultural farms.

This excerpt is from an article in the 7/03 - 8/03 issue of Natural History magazine.

This article summarizes the information in this scientific paper:

Rice, R. and Greenberg, R.S. The Chocolate Tree. Natural History Magazine. 112(6): 2003. pp.36-43.