Guatemala, a small country in Central America, has a large bird community. Its tropical forests are the winter home of a great variety of migratory birds from North America which join a diverse assemblage of resident birds.
To better understand Guatemala's birds, scientists studied six major habitats in the Polochic Valley of Guatemala:
In this part of Guatemala, coffee may be grown in the sun much like corn, or under a short canopy of trees dominated by the genera Inga or Gliricidia. The trees are heavily pruned so that there is a gap between the coffee shrubs and the canopy. Insecticides are widely used to keep pests at bay and herbicides are applied to combat weeds.
Abandoned corn fields, cardomom grown under a natural forest canopy, and native forest rounded out the habitats studied.
Not surprisingly the forest remnants, even small patches, were the best habitat for birds and supported both resident and migratory species. The shaded cardomom plantations were fairly similar in their appeal to birds.
Of the coffee farms, the Inga-dominated canopies were the best for birds and similar to the regenerating corn fields. Gliricidia and sun coffee were the least popular among birds.
Note that coffee grown under tall, shaded, unpruned canopies in nearby Chiapas, Mexico were even better for birds, and almost as good as natural forest.
This article summarizes the information in this publication:
Greenberg, Russell S., Bichier, Peter, Cruz, A. and Reitsma, R. 1997. Bird populations of sun and shade coffee plantations in Central Guatemala. Conservation Biology, 11: 448-459.
We studied the avifauna of sun and shade coffee plantations and associated mid-elevation habitats during the dry season of 1995. The three plantation types (Inga, Gliricidia, and sun) showed high faunistic similarities with each other and were both distinct and depauperate compared to matorral and forest patch habitats. Of all the coffee plantation habitats, Inga shade had the highest diversity. Species associated with wooded vegetation were more common in shade plantations, particulary in Inga. A second census showed a decline in bird numbers that was more pronounced in sun and Gliricidia than in Inga plantations. Overall, differences between the plantation types were small and all coffee plantations were less diverse than traditional coffee farms previously studied in nearby Chiapas, Mexico. The relatively low bird diveresity was probably due to the low stature, low tree species diversity and heavy pruning of the canopy. These features reflect management paractices that are common throughout Latin America. The most common species of birds in all coffee plantation habitats were common second-growth or edge species; more specialized forest species were almost completely absent from plantations. Furthermore, many common matorral species were rare or absent from coffee plantations, even in plantations with which matorral shares a similar superficial structure. Coffee plantations probably will only be important for avian diversity if a tall, taxonomically and structurally diverse canopy is maintained. We suggest this is most likely to occur on farms that are managed for a variety of products rather than those designated entirely for the production of coffee.
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