Science

Preserving wildlife to benefit farmers

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Until the next asteroid hits Earth, it is people -- more than any other force -- who will determine the future course of all known life.  During the current 100-year period, it appears likely that we will drive about half of Earth’s animals and plants to extinction through our day-to-day activities.

One probable culprit is food. Crop and pasture lands now cover 40% of the world’s land surface – the most productive lands favored by people and also by the many other animals and plants that run Earth’s life-support systems. To feed the growing human population, food production must double by 2050—and humanity’s great challenge is to accomplish this while restoring and sustaining the vital parts of Earth’s life-support systems. 

In the Center for Conservation Biology, our core objective is to find ways to meet this challenge. Our work has shown startlingly high numbers of birds, insects, mammals, and plants live in the farming countryside of southern Costa Rica, a place that typifies much of the tropics. A network of small forest patches snakes over hills and into valleys where coffee and other crops are grown. Many farmers choose to leave native trees interspersed throughout their plantations and plant several types of crop in the same agricultural plot. When we extended our studies to vast commercial farms, planted with a single crop species, the wildlife disappeared. We began to wonder how to encourage farmers to manage their lands for wildlife, leaving trees and forest patches intact. 

One way might be by quantifying the benefits, both economic and otherwise, that nature provides for us. Forests stabilize the climate, purify water, and help control flooding.  And we found that they support small, stingless bees that pollinate the coffee, boosting farmer yields by 20 percent and increasing income by US$60,000 per year on a single farm!  Now we are quantifying pest-control services from forest.

Five years ago, a small beetle named the Coffee Berry Borer (Hypothenemus hampeii) arrived in Costa Rica. The Coffee Berry Borer is coffee’s primary pest, responsible for over $500 million in lost coffee, annually. Pesticides have proven ineffective and dangerously toxic for farm workers. Last year, we built cages around coffee plants that excluded native birds and bats. Safe from their predators, the Coffee Berry Borer thrived inside the cages, consuming more berries inside cages than outside cages. We now know native birds and bats provide farmers with a great service but many questions remain. Which birds and bats are the primary predators? Are these the same species that need nearby forest patches to survive? What would happen if the farmers decided to cut down the trees that are sprinkled throughout their plantations?

What will we do?

Next spring, we will return to tackle some of these questions. New techniques from molecular biology have made it possible to discover what animals eat by scanning their feces for prey DNA. After safely trapping and releasing bats and birds, we will collect and scan their feces for Coffee Berry Borer DNA. From preliminary samples, we have already identified one important predator, the Rufous-capped Warbler (Basileuterus rufifrons), but we know that there are others, waiting to be discovered.

Coffee is the #1 export from developing countries after petroleum. Once we have identified the birds and bats that feed on the Coffee Berry Borer, we will begin to predict how farm practices could do most to control pests and provide a healthy product. In developing these sorts of “best practices” in a prime coffee growing region of Costa Rica, we aim to make life better for birds, bats, and all of us – there and worldwide. Only the Coffee Berry Borer might not agree.

What will we deliver?

By donating to our cause in the SciFund Challenge, your funds will support all aspects of our research, from quantifying Berry Borer damage on farms to molecular analyses in the lab. Because our results will be relevant for scientists, farmers, conservation organizations, and government officials, we will disseminate our findings very widely. In addition, we will contribute our knowledge of pest-control services to the Natural Capital Project (www.naturalcapitalproject.org), a larger effort that seeks to identify, map, and mainstream the many benefits humanity receives from nature into all major decisions.