MSU Extension Agrifood Safety

Patrick Gordon
Michigan Produce Safety Technician

Birds are an important part of the ecosystem, but they can also pose a serious threat to food safety and produce quality when they build their nests in critical spaces on the farm. Early season is the best time to establish a wildlife monitoring and prevention plan in order to prevent contamination during growing and harvesting.

Nesting birds pose a serious health risk when positioned above produce or food contact surfaces. Anything below the nest typically ends up covered in bird poop, passing on any human pathogens the bird is carrying to anything contacting the poop. It is especially concerning when the produce contact surface is a grader, harvest containers or other similar equipment used in production that could potentially contaminate a major portion of a harvest.

Birds pose additional food safety threats when nesting in production areas, especially fruit trees and bushes. These situations can be increased when utilizing mechanical harvesting techniques. For example, when mechanically harvesting blueberries, the harvester cannot determine it is picking blueberries, bird nests, or birds. This can pose a problem, as the picking system, conveyors, harvest bins, and all the blueberries could be contaminated with the nest, the birds, and everything that comes with it.

There is no single solution or approach to monitoring and preventing bird contamination. The best plans will use a combination of approaches. Anybody working on the farm typically understands wildlife patterns, this is true for birds in production areas and pack houses. Noticing areas with more than usual bird traffic and areas with a large amount of bird poop will help to focus mitigation efforts.

In packhouses and other buildings mitigation focus should be on roosting points, especially those areas with a large amount of bird poop. There are ways to prevent birds from inhabiting and nesting in these areas. Sealing buildings in ways that prevent wildlife from entering is the most effective technique, though many times this is not an option. Bird netting stretched throughout the rafters is also a good option, though it can be pricy, especially if there is a large area to cover.  Perhaps a more affordable option is disturbing the major roosting points, making them uncomfortable, or unable to nest or roost. The use of nails or other sharp metals in these areas could also be effective.

In production fields, there are many different bird deterrents that have various efficacy depending on how they are used. Visual deterrents such as scare crows, inflatable tube men, dead crow decoy, or something as simple as reflective tape on bushes and trees can be effective if used properly. There are several other options that could be explored with variable efficacy and price points, such as laser systems and noise cannons. Birds are smart, they tend to learn patterns used with deterrents quickly, so stationary deterrents need to be frequently moved around exclusion areas in order to retain their efficacy.

When excluding birds from areas it could be beneficial to provide alternative nesting areas in order to retain the positive traits that they bring to the farm. This will hopefully prevent them from returning to the areas where they were previously a problem.

 As is the case when creating any wildlife mitigation strategy, it is important to understand local, state, and federal laws that may be associated with the specific target animals. Local Produce Safety Technicians can help navigate these laws and regulations and create effective wildlife mitigation and monitoring plans.