Are coffee farms for the birds? Yes and no

APRIL 29, 2019

by University of Utah

Over 11 field seasons, between 1999 and 2010, ornithologist Cagan Sekercioglu trekked through the forests and coffee fields of Costa Rica to study how tropical birds were faring in a changing agricultural landscape. Through painstaking banding of individual birds, Sekercioglu asked whether the expansion of coffee plantations is reducing tropical bird biodiversity.

The answer, published this week in Proceedings of the National Academy of Sciences, is no. And yes. Sun coffee plantations are able to host a surprising number of bird species, even more if the plantation has some tree cover. But the plantations are not enough to maintain bird biodiversity.

"It's two sides of a coin," Sekercioglu says. "These tropical agricultural habitats that are mostly deforested still maintain large numbers of tropical species. Even small patches of trees can make a difference and help some species. But the flip side of the coin is, in the long term, most of these species are still declining."

The only way

The seeds of this project were planted in 1996 when Sekercioglu, then an undergraduate at Harvard University, was studying the effects of logging on tropical bird communities in Uganda. "I wanted to continue that research in grad school," he says, "but I wanted something long term. Not just a quick snapshot, but a multiyear study where I could look at long-term population change."

Such long-term studies are rare, partially because of the research timeline of a typical graduate student. Doctoral students in biology may be able to collect four years of data before compiling their research into a dissertation to complete their degree. But Sekercioglu wanted more than four years. To get the long-term trends he wanted, he needed at least six years. Ten would be even better.

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Birds bug out over coffee

Research on coffee farm habitats can help both fowl and farmers

Date:  March 27, 2019

Source:  University of Delaware

Coffee grown under a tree canopy is promoted as good habitat for birds, but recent University of Delaware research shows that some of these coffee farms may not be as friendly to our feathered friends as advertised.

Working with geographer Robert Rice of the Smithsonian Migratory Bird Center (SMBC), University of Delaware Professor of Entomology Doug Tallamy and former UD graduate student Desirée Narango studied canopy tree preference of birds in shade-coffee farms with a particular focus on the implications for migratory birds that spend the winter in neotropical coffee farms. The research was published in the journal Biotropica.

Americans drink a lot of coffee -- 64 percent of those aged 18 or over had at least one cup per day. That's more than 150 million people in the U.S. and we all know one cup is a light day for many of our friends and family. This incredible demand for coffee means a lot of land in tropical zones is used to grow coffee beans in neotropical countries like Colombia and Nicaragua (where the UD study took place). Across central and South America, land converted to coffee agriculture occupies more than five million hectares of what was once prime overwintering natural habitat for migratory birds.

"Coffee grows right at the altitude that most of our neo-tropical migratory birds are spending the winter, particularly species that are losing one to two percent of their population every year like the cerulean warbler, Canada warbler and wood thrush," said Tallamy. "A lot of this land has been leveled for coffee farms."

Continued