Birds of Prey: Partners in Co-management

3 days ago
4 min read

Produce safety is not the only concern growers have on their minds when navigating the daily challenges of farming, and in some cases, might not even be the paramount concern of the moment. These other challenges can be economic, environmental, ecological, or social. So when we think about addressing produce safety on the farm, it is worth considering ways that we can integrate produce safety strategies while addressing the multitude of other concerns at hand. Multifunctional strategies can have a far greater impact and appeal to growers, as the investment in their implementation can be seen through a wider lens. An example of a multifunctional strategy is the integration of birds of prey as a method of pest management in growing operations. This integration is an example of co-management “...practices which minimize risk of fecal contamination and microbiological hazards associated with food production while simultaneously conserving soil, water, air, wildlife, and other natural resources.” (Produce Safety Alliance) The presence of these predators acts as a passive mode of pest population management, and in in turn, a risk reduction strategy for any pest-related produce safety concerns. Integration requires minimal financial investment and annual maintenance from the growers and offers a tapestry of benefits for the local ecosystem and growing operation as a whole.

There are a handful of publications that have studied the effects that birds of prey can have on growing operations. A recent study conducted in Michigan explored the effects that falcon nesting boxes in sweet cherry orchards would have on reducing pre-harvest food safety risks and crop damage caused by wild bird populations. (1) When compared to control orchards, the researchers found that the presence of falcons reduced the overall density of birds by roughly half and led to fewer recorded instances of crop damage (11.37 times less likely) and fecal contamination events in and around fruit zones (3.26 times less likely). In another study, researchers explored the effectiveness of Ural owls at controlling vole populations in Japanese apple orchards. (2) In this study, the researchers erected nesting boxes and monitored the vole populations throughout the growing season, and found that owls could reduce vole populations by 53-70% during the spring rearing season and impart a season-long suppression of the vole population within the owls' breeding area. Similarly, a global study on Barn Owls recognized their value and efficiency as a species for pest management. In California vineyards, it is estimated that a single family of Barn Owls removes an average of 3466 rodents each year. (3)

Despite the differences within these studies, an obvious trend arises that shows making space for birds of prey in a growing system can positively impact the ecology of the surrounding area and reduce pre-harvest produce safety risks through a reduction of pest populations. It is also important to note that growers should always think critically when integrating a new animal into their growing operation, and in this case, what concerns may arise through the presence of birds of prey, like falcons or owls. In response to these concerns, precautions should be taken in the placement of nesting boxes, such as not directly over covered produce, and growers should monitor for any unintended impacts on produce safety. While there will always be inherent risk when integrating animals into a growing system, the benefits and management of pest populations can far outweigh the risks if done consciously and with active care.

It is worth mentioning some additional considerations to take into account when implementing a co-management strategy involving birds of prey. Firstly, there must be a general alignment between the bird of prey, the greater farm ecosystem, and the crop of interest. Not all species will be attracted to nest in the same spaces, and growers should consider if the surrounding environment of their farm provides all the necessary habitat and resources needed for the specific bird of interest. In the same light, not all crops will benefit equally from the presence of a bird of prey if their life cycles do not align. Heightened predation activity, like chick rearing, that overlaps with periods of interest during the crop cycle, such as fruit ripening, should be determined. (Contact your local technician for assistance!) It should also be noted that birds of prey are particularly susceptible to toxic compounds through the process of bioaccumulation. If your operation chooses to make room for these helpful partners, take extra precautions about what you and even your neighbors may be applying to your cropping systems, and avoid the use of rodenticides. If you are fortunate to have one of these predators take up residence, remember that the populations of predator and prey will fluctuate in a given season, depending on the availability of resources and ecological factors. Birds of prey should be seen as partners and integrated as an additional factor in a wide array of strategies to manage pest populations. Through pest population reduction, the likelihood of contamination events is reduced, along with providing a multitude of benefits for the growing operation as a whole.

Next Box Construction Plans for Common Michigan Birds of Prey:

Article Sources:

“Falcons reduce pre-harvest food safety risks and crop damage from wild birds” - https://besjournals.onlinelibrary.wiley.com/doi/10.1111/1365-2664.70209
"Effectiveness of vole control by owls in apple orchards" - https://besjournals.onlinelibrary.wiley.com/doi/full/10.1111/1365-2664.13295
“Barn Owls as a Nature-Based Solution for Pest Control: A Multinational Initiative Around the Mediterranean and Other Regions” - https://www.mdpi.com/2673-7159/4/4/39
“Owls Contribute to an Integrated Pest Management Program” - https://ucanr.edu/blog/real-dirt/article/owls-contribute-integrated-pest-management-program-0