This Small Falcon Protects Cherry Crops Better than Scarecrows and Sprays

Farmers are well aware of the problems birds can cause in orchards, from eating fruits and harming leaves to leaving droppings on plants. Beyond being unsightly, bird droppings pose a food safety threat, as they can carry harmful pathogens like Salmonella and E. coli, which continue to raise concerns for human health. A new study in the Journal of Applied Ecology suggests a gentler alternative to traditional bird deterrents such as nets or chemical sprays.

Researchers at Michigan State University explored the use of the American kestrel (Falco sparverius), a small falcon native to the United States, as a natural crop protector. Primarily insectivores, these tiny birds of prey occasionally hunt small birds or mammals. Scientists hypothesized that kestrels could help keep pest birds like robins, starlings, and grackles away from orchards.

The research took place in 16 sweet cherry orchards in northern Michigan, half of which had kestrel nesting boxes installed. The team monitored bird presence, droppings, and crop damage along transects within the orchards. Pest birds were briefly captured using lightweight nets, and fresh fecal samples were collected to test for bacteria, focusing on Campylobacter spp., a common foodborne pathogen responsible for human diarrhea.

Orchards with active kestrel nests showed a notable decrease in pest bird activity and a threefold reduction in bird droppings compared to orchards without kestrels. "They're really effective at lowering the amount of droppings," said agroecologist Olivia Smith, a co-author of the study.

Approximately 10% of fecal samples contained Campylobacter spp.. While this does not guarantee transmission to humans through harvested cherries, it emphasizes the importance of limiting bird presence in food crops. Installing kestrel boxes could benefit both farmers and falcon populations, which are declining according to the International Union for Conservation of Nature.

"Our results indicate that encouraging birds of prey through nest boxes may help growers conserve a declining species, reduce crop damage, and lower in-field fecal contamination that can lead to foodborne illness," the authors wrote.

This approach offers a unique combination of improved food safety and raptor conservationan ecological win for both orchards and wildlife.

Analysis: A Natural Solution to Pest Bird Problems in Orchards

The findings from the Michigan State University study present a compelling case for integrating kestrels into orchard management. This approach offers a dual benefit: reducing crop damage and improving food safety while also aiding in the conservation of a declining raptor species. By introducing kestrel nesting boxes, farmers not only deter pest birds but also contribute to the broader ecological goal of preserving biodiversity.

While traditional bird deterrents like nets or chemical sprays can be effective, they come with their own set of challenges. Nets can be unsightly and costly, while chemicals raise concerns about potential harm to the environment and human health. The Michigan study offers an alternative that is both environmentally friendly and cost-effective. Installing kestrel boxes could provide a sustainable long-term solution for orchards looking to minimize the risks associated with pest birds.

Importantly, the study highlights the connection between bird droppings and foodborne illness risks. With Campylobacter spp. found in a portion of the bird droppings, this research underscores the need for innovative methods to control pest bird populations in food production environments. Encouraging the presence of kestrels could reduce the risk of contamination and, consequently, the public health risks associated with bird droppings on crops.

Beyond its practical benefits, this method is a step toward more integrated and wildlife-friendly agricultural practices. It shows how small adjustments—such as the installation of nesting boxes—can have a meaningful impact on both crop protection and biodiversity. As such, the study sets a precedent for future research and potential policy changes in agricultural pest management.

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• Forget Scarecrows and Sprays. This Tiny Falcon Keeps Cherry Crops Safe