Chestnut-sided warbler
Chestnut-sided Warbler a North American Migrant species that winters in Central America

This is the first time scientists have assigned a monetary value to the pest-control benefits rainforest can provide to agriculture. Their study could provide the framework for pest management that helps both farmers and biodiversity.

To quantify the benefit resident and migratory birds provide to coffee plantations, the researchers calculated bean yield of infected plants that were housed in bird-proof cages versus yield from infected plants open to beetle-eating birds.  In recent years, Stanford biologists have found that coffee growers in Costa Rica bolster bird biodiversity by leaving patches of their plantations as untouched rainforest.

The latest finding from these researchers suggests that resident and migratory birds are returning the favor to farmers by eating an aggressive coffee bean pest, the borer beetle, thereby improving coffee bean yields by hundreds of dollars per hectare.

The study is the first to put a monetary value on the pest-control benefits rainforest can provide to agriculture, which the researchers hope can inform both farmers and conservationists. [Source]