Ecosystem services as an economic incentive for conservation of an agricultural habitat

Biological pest control is a vital ecosystem service that helps to maintain natural and agricultural systems worldwide.  Specific knowledge of this ecosystem attribute is commonly lacking, meanwhile the integrity of many ecological services is being compromised by modern agricultural intensification.  Coffee farms affect biogeographically diverse regions where simplification of vegetative cover to increase production is degrading suitable habitat for tropical biodiversity.  The coffee-berry borer, Hypothenemus hampei is the world’s most common coffee pest.  Birds have been shown to control insect populations and increase with the complexity of vegetation cover.  We conducted a bird exclosure experiment, bird surveys, and vegetation assessments across four Blue Mountain coffee farms in Jamaica, West Indies, November 2005 through April 2006 to (1) determine if birds control this specific global coffee pest, (2) link borer predators with greater vegetation complexity, and (3) calculate the economic benefit of observed pest reductions as increased yield and farm income, providing an conservation incentive to farmers.  Coffee plants with no bird predation had significantly greater levels of berry-borer infestation, more infested berries with borer broods, and deeper penetration of bored berries than paired control plants.  Abundance of birds foraging in coffee increased with greater shade cover, although individual species trends varied.  The market value of increased saleable berries attributable to suppression of coffee berry-borer by birds for the production year ranged from US$17 to US$58 per acre.  Shade tree habitat in coffee agroecosystems represents an ecologically and economically important resource and a valid target for conservation.