Wine-Friendy Poop! Bluebird Feces Key to Healthy Vineyards in California

Research showed that bluebirds inhabiting the California vineyards are beneficial to the winegrowers after studying their poop.

The new study published in The Auk: Ornithological Advances led by Julie Jedlicka from Missouri Western State University, aims to study the diet of Western Bluebirds (Sialia Mexicana). The experiment required the installation of nest boxes at a California vineyard to attract hundreds of birds that picked the farmers' crops clean of pests in exchange for the free housing. Using a new approach called "molecular scatology," Jedlicka and her colleagues analyzed the DNA fragments in the birds' feces and found more than what they asked for.

"Placing songbird nesting boxes in agricultural landscapes can provide suitable nesting sites for a lot of birds that used to be plentiful 100 or 200 years ago but lost their natural landscapes," said Julie Jedlicka, an ornithologist at the University of California, Berkeley.

In a report from ScienceDaily.com, Ecosystem Expert Matthew Humboldt of Humboldt State University states that "this study provides important new insights, both in terms of its findings on bluebird diets in vineyard ecosystems and in its advances in molecular diet analyses."

After collecting 237 samples from adult and nestling bluebirds in Napa County, California, the team of researchers found that these Western Bluebirds mostly ate mosquitos and herbivorous insects which are pests to the vineyards. With this, Jedlicka hopes to encourage vineyard owners to install boxes to replace the natural tree houses that were cleared for the vineyard.

"Even though the authors did not find specific pest species in bluebird diets, they did confirm that bluebirds are mainly eating herbivorous insects, including those in the same families as major pests. This suggests bluebirds may contribute to ecosystem functioning in these systems. Their work also illustrates the power of new techniques to reveal bird diets and marks new advances in scatology," Humboldt added.