American kestrels provide important 'ecosystem services'

May 15, 2018 by Cheryl Dybas, National Science Foundation
A male kestrel in a northern Michigan cherry orchard. Males have gray wings; females, rusty wings. Credit: Catherine Lindell

America's smallest raptor, the American kestrel, can boost economies in Michigan and other fruit-growing states, new research shows. It's the first study to measure regional job creation aided by the activity of native predators.

American kestrels range from Alaska to South America. They dine on bugs, small mammals and fruit-eating . More kestrels mean fewer pests, and the tiny hawks' mere presence can produce measurable improvements, said Catherine Lindell, a Michigan State University (MSU) integrative biologist and study co-author. Growers can attract more of these beneficial birds by building nesting boxes.

A paper reporting the results was published today in the Journal of Applied Ecology.

"This research demonstrates that farmers can use science to design agricultural fields that benefit people and wildlife," said Betsy Von Holle, a program director for the National Science Foundation's (NSF) Dynamics of Coupled Natural and Human Systems program, which funded the research.

Lindell and her team calculated the benefit-to-cost ratios of installing kestrel nest boxes around orchards. The results showed that, for every dollar spent, $84 to $357 of sweet cherries are saved from fruit-eating birds.

To scale up the projections, the team used regional economic modeling. The models predicted that increased sweet cherry production from reduced bird damage would generate 46 to 50 jobs, which translates to a major contribution to Michigan's economy.

Ripe sweet cherries in an orchard with kestrel nest boxes installed. Credit: Catherine Lindell

"Having more American kestrels around orchards reduces the number of fruit-eating birds significantly," Lindell said. "It's not just a microeconomic boost that simply benefits the fruit grower—it has a macroeconomic effect that benefits the state's economy."

Added Von Holle, "Fruit-eating birds avoid orchards with American kestrels, so those with kestrel nest boxes end up producing more cherries. If kestrel nest boxes were used more widely, these researchers estimate, Michigan would benefit by adding new jobs and more than $2 million in increased revenue over a five-year period."

The strategy isn't limited solely to Michigan cherry producers. It's a potential boon for fruit producers throughout the kestrels' range, and is a cost-effective ecosystem service, the scientists said.

Finishing the installation of a nest box and tower before kestrels migrate to northern Michigan. Credit: Catherine Lindell

Though building nest boxes doesn't always guarantee a booming kestrel population, "installation and maintenance costs of boxes are small, and even if box occupancy rates are low, they can direct kestrel activity to particular places in agricultural landscapes where kestrels can deter birds that are fruit pests," said Megan Shave, MSU integrative biologist and first author of the journal paper.

Although birds make up only 2 percent of kestrels' diets, just having the feathered enforcers in the area keeps many fruit-eating avian species out of orchards. These improvements give fruit growers another, more sustainable option to conventional pesticide-based crop protection, Lindell said.

Stephanie Shwiff and Julie Elser of the U.S. Department of Agriculture's National Wildlife Research Center performed the economic analyses for the study.

Scientists add wood chips to the bottom of a kestrel nest box. Credit: Catherine Lindell

The view inside a nest box: Kestrels in northern Michigan usually lay four or five eggs. Credit: Catherine Lindell

Explore further: American kestrels, most common predatory birds in U.S., can reduce need for pesticide use

Related Stories

Malic acid encourages sweet cherry cracking

July 29, 2015

"Cracking" is a problem for sweet cherry production wherever the high-value crop is grown. However, despite considerable research, the reason that this phenomenon occurs has not been clear. In a new study, Andreas Winkler, ...

Birds help keep vineyards pest-free

November 9, 2011

Properly functioning ecosystems have their own pest management system – predation – but as new manmade ecosystems develop, these natural maintenance systems are often disrupted. In some cases, though, installing ...

Inflatable 'scary dancers' chase birds from fruit

December 5, 2013

(Phys.org) —Those large, inflatable plastic characters that loom over used car lots have a new purpose: scaring away birds that cause hundreds of millions of dollars in damage to U.S. orchards and vineyards.

Recommended for you

Revealing the mysteries of early development

May 23, 2018

Zebrafish embryos are transparent and develop outside the mother's body, enabling scientists to get a detailed view of early development. A research team led by Lila Solnica-Krezel, the Alan A. and Edith L. Wolff Distinguished ...

Study bolsters bats' reputation as mosquito devourers

May 23, 2018

It's a common assumption: Bats are important because they feast upon those pervasive warm-weather pests known as mosquitoes. You want to see bats flying above, cleaning up the night sky and ridding you of itchy bites and ...

Why birds don't have teeth

May 23, 2018

Why did birds lose their teeth? Was it so they would be lighter in the air? Or are pointy beaks better for worm-eating than the jagged jaws of dinosaur ancestors?

'Virtual safe space' to help bumblebees

May 22, 2018

The many threats facing bumblebees can be tested using a "virtual safe space" created by scientists at the University of Exeter. Bumble-BEEHAVE provides a computer simulation of how colonies will develop and react to multiple ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.