Bringing out the best in wild birds on farms

California quails tend to provide more benefits to strawberry growers than bad services, according to the "Multifunctionality Index" of a University of California, Davis study of birds that the commonly found on farms. Photo by Danny Karp, UC Davis

A supportive environment can bring out the best in an individual, even for a bird.

After an outbreak of E. coli in 2006 devastated the spinach industry, with farmers forced to remove natural habitat to prevent wildlife – and the foodborne pathogens they can sometimes carry – from visiting crops. A study released today by the University of California, Davis shows that farms surrounded by natural habitats benefit birds the most, including less crop damage and fewer food safety risks.

The study, published in the Journal of Applied Ecology, was conducted in 21 strawberry fields along the central California coast. Birds were found to be more likely to carry pathogens and eat berries without a surrounding natural habitat.

The authors said a better understanding of the interplay between agricultural practices, the landscape, and the roles birds play in ecosystems can help growers get the most out of wild birds near their fields. .

"Bird communities respond to changes in the landscape," said lead author Elissa Olimpi, a postdoctoral fellow in the Department of Wildlife, Fish, and Conservation at UC Davis at the time of writing. study. "As birds change in response to management, the costs and benefits they provide also change."

The most important driver

The study looked at how different farming practices influence the costs and benefits that wild birds provide on strawberry farms. Scientists combined nearly 300 bird surveys and molecular analyzes of more than 1,000 fecal samples from 55 bird species to determine which birds fed on pests, beneficial insects and crops, and were carriers. foodborne pathogens.

They also ranked the birds to see which were most likely to bring benefits or costs to farmland. Barn swallows, for example, earned a "gold star" in the study, Olimpi said. Their mud nests are usually seen clinging to the underside of barn eaves, from where they take off to fly over fields, feeding on insects.

But rather than ending up with a list of 'good' and 'bad' birds, the study found that most bird species brought both costs and benefits to farms, according to how the landscape was managed.

The presence of a natural habitat was the main differentiator of a farm where wild birds brought more benefit than harm.

“Nature is messy and birds are complex,” Olimpi said. “The best we can do is figure out how to reap the benefits while reducing the harms. Producers will tell you that you can't keep birds off your farm — you can't and you don't want to from a conservation perspective. So how can we take advantage of the services provided by birds?"

Win-win for birds and farms

The study is one of several publications from the laboratory of Professor Daniel Karp at the University of California, Davis that highlights the environmental, agricultural and food security impacts of conserving bird habitat around the farms. A related study in 2020 found that farms with natural habitat attracted more insectivorous birds — and fewer strawberry-eating birds — so farmers experience less berry damage on farms with more habitat to eat. proximity. These habitats also bring a greater number of bird species into the landscape.

"Overall, these studies suggest that agricultural landscapes with natural habitat tend to be good for conservation, farmers, and public health," Karp said.

Other co-authors of this study include Karina Garcia and David Gonthier of the University of Kentucky, Claire Kremen of UC Berkeley and the University of British Columbia, William E. Snyder of the University of Georgia and Erin Wilson-Rankin of UC Riverside.

The research was funded by the USDA and UC Davis Department of Wildlife, Fish and Conservation Biology.

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Focus Area Tags: Agriculture, Environment,