Birds Protect Costa Rico’s Coffee Crops
Millions of people around the world could not imagine starting the day without a cup of coffee. Coffee production plays a major role in the economy of a number of Central and South American countries, including Costa Rica, where ongoing research has highlighted the role local birds play in protecting one of the most lucrative crops in the world – coffee. Stanford University graduate student Daniel Karp and a group of researchers recently published a paper in Ecology Letters where they detail how birds control populations of coffee borer beetles (Hypothenemus hampei) in Costa Rican coffee plantations, increasing the yield per hectare significantly.
Originating in Africa, the coffee borer beetle has spread around the world and is found wherever coffee is grown. This small brown beetle is very destructive and difficult to control, causing an estimated $500 million in damage every year. The female beetle burrows its way into the coffee berry and lays up to 50 eggs. Little white maggots hatch from the eggs and consume the coffee berry from the inside. In coffee plantations where patches of rainforest habitat were left undisturbed, damage by coffee borer beetles was noted to be much less resulting in higher yields.
In determining what contribution birds are making to the coffee economy of Costa Rica, researchers carried out calculations on how much yield could be expected if there were no borer beetles to contend with. They then made a comparison between infested plants left in their natural condition, and infested plants grown inside bird-proof enclosures. It was concluded that, taking the season into account, birds improve yield per hectare by between $75 and $310.
In order to determine which birds were eating the beetles, researchers took bird faeces back to the laboratory at Stanford to test the DNA. One of the bird species identified as a coffee borer beetle eater is the yellow warbler. The research results will be used to show Costa Rican coffee farmers that it is advantageous to protect rainforest habitat on their land – both for the birds and for the coffee crop.