- Fruits: cherries
- Pest Management: Nest Boxes
New nest boxes installed in Michigan cherry orchards since 2012 have been used extensively by kestrels. We used nest box video cameras to determine that kestrels provision their nestlings with known orchard pests, including grasshoppers, voles, and fruit-eating birds; furthermore, we observed generalizable trends in kestrel prey removal based on nestling age, seasonal timing of prey availability, brood size and sex ratio, weather, and adult female movements relative to the nest box. We used transect surveys to determine that fruit-eating bird counts were lower in orchards with active kestrel nest boxes, thus kestrel activity associated with nest boxes likely acts as a reliable cue of predation risk that, in combination with direct consumption, reduces fruit-eating bird abundances in orchards. Finally, we previously used live-trapping to determine that summer small mammal abundances were lower in orchards with active kestrel boxes and orchards that had been more recently mowed; however, these differences did not carry over as differences in winter presence in orchards, when mammal damage to trees is most likely. We therefore present recommendations for future work on small mammal abundances in orchards.
This project resulted in the installation of 25 nest boxes in cherry orchards throughout Leelanau County, MI and prompted an expansion of our nest box program into the blueberry-growing region of southwestern MI. Presentations at MSU Extension workshops and farmer expos reached dozens of cherry and blueberry growers in MI, and press releases about this project have the potential to reach growers nationwide. Ongoing research, funded by a National Science Foundation Dynamics of Coupled Natural and Human Systems Grant, will use a national survey of fruit growers and in-person interviews, along with modeling approaches, to investigate factors that influence grower adoption of predator nest boxes as a pest management practice.
Objective 1) Effects of kestrel nest boxes and supplemental perches on kestrel presence and fruit-eating bird abundances in orchards:
Objective 2) Effects of kestrel nest boxes and supplemental perches on winter rodent abundances in orchards:
Objective 3) Estimating number of prey removed and extent of prey removal by kestrels breeding in orchard nest boxes: