Forest bolsters bird abundance, pest control and coffee yield

Efforts to maximise crop yields are fuelling agricultural intensification, exacerbating the biodiversity crisis. Low-intensity agricultural practices, however, may not sacrifice yields if they support biodiversity-driven ecosystem services. We quantified the value native predators provide to farmers by consuming coffee's most damaging insect pest, the coffee berry borer beetle (Hypothenemus hampei). Our experiments in Costa Rica showed birds reduced infestation by 50%, bats played a marginal role, and farmland forest cover increased pest removal. We identified borer-consuming bird species by assaying faeces for borer DNA and found higher borer-predator abundances on more forested plantations. Our coarse estimate is that forest patches doubled pest control over 230km(2) by providing habitat for 55000 borer-consuming birds. These pest-control services prevented US$75-US$310ha-year(-1) in damage, a benefit per plantation on par with the average annual income of a Costa Rican citizen. Retaining forest and accounting for pest control demonstrates a win-win for biodiversity and coffee farmers.