The damage done by pests can be extensive, from structural deterioration and contaminated product, causing facilities to lose money, to health issues, spreading illnesses that can make consumers sick. When thinking about the pests that most typically invade food facilities, cockroaches, rodents, flies, and stored product pests are most likely the first few to come to mind. However, pest birds are frequent threats to food facilities, too. And if birds aren’t properly managed, they will waste no time in establishing their flocks and inflicting harm to property, product, and people.
Why is Bird Management Important for Food Facilities?
Because bird droppings can contaminate food, as well as damage structures, certain species of birds are considered serious nuisance pests. Proper actions must be taken to exclude them from entering buildings, as well as prevent them from nesting or gathering outside of facilities, where they pose a contamination hazard. The federal Food, Drug, and Cosmetic Act prohibits any conditions that could result in food contamination; therefore, it is necessary to discourage birds from nesting in exterior areas where fecal matter, feathers, or hazardous nesting materials could contaminate product or packing materials on loading docks.
Nests located inside, on roofs, or in the eaves of facilities are a health hazard both for employees and consumers. Bird droppings can enrich the soil below to promote growth of the fungus Histoplasma capsulatum, the spores of which can, when inhaled, result in histoplasmosis, a respiratory disease. The inhalation of just a couple of spores can cause mild cases in people, and the threat is most severe from nests or roosts that have been abandoned for a significant period of time. Once droppings have dried out, the right conditions are more likely to develop that can cause spores to be released. Nests are also a draw for a variety of insects and ectoparasites that cannot be tolerated in any facilities handling food products.
Salmonellosis is another common illness spread by pest birds. Salmonella bacteria can be found in pigeons, sparrows, and starlings, all of which commonly invade food production and storage facilities. The illness can be spread to humans when infected bird droppings come in to contact with food, either from above or when the Salmonella organisms are carried on the feet or bodies of birds that land on food products.
Common Pest Birds
European starlings, house (English) sparrows, pigeons, and Canada geese are four of the most likely bird species to cause problems in or around food storage and production facilities.
European starlings are likely best recognized for their tendency to gather in large, loud roosting flocks. Starlings are known to carry more than 25 diseases, including encephalitis, histoplasmosis, and salmonellosis. Ectoparasites—primarily mite species—are also associated with starling nests and droppings. Starlings will nest in just about any nook or crevice in and around structures. Because starling flocks can easily number in the high-hundreds, one flock can create a massive mess with their droppings.
House sparrows are not actually true sparrows, but a member of the weaver finch family. House sparrows are known to carry more than 29 diseases and ectoparasites, and they are considered one of the major carriers of St. Louis encephalitis. They prefer to nest in protected areas in, on, or near buildings such as structural ledges, gutters, light fixtures, and inside warehouses. Sparrows tend to re-use the same nesting sites over and over again. They feed mainly on seeds or grains. House sparrows are common invaders of warehouses and food processing plants, where their droppings could contaminate products.
Pigeons can be found in virtually every U.S. city and in most rural areas. They are notoriously dirty birds, capable of spreading more than 50 diseases and ectoparasites. They prefer feeding on seeds, grains, and fruits, but will really eat just about anything, including garbage, animal matter, and manure. They typically build their nests on ledges of structures and roost on perches that are high off the ground. Pigeon droppings are highly acidic which can cause damage to building exteriors, and their droppings, feathers, and nesting materials can contaminate food products.
Canada geese are not typically a problem inside food facilities, but can cause significant nuisance problems outside of facilities. This previously migratory species now often overwinters in the U.S. wherever food is abundant. They nest at the edges of bodies of water, such as ponds or swamps, and around buildings near bodies of water. When large flocks of geese overrun an area, their large and numerous droppings quickly become a foul nuisance.
Prevention of Birds In and Around Facilities
Before embarking on any bird management plan, it is necessary to determine if there are any laws pertaining to the situation. Federal law protects all birds with the exception of the common pigeon, and some local laws might block certain methods of bird management. Be sure to check federal, state, and local laws and ordinances to see if they affect the bird species causing issues and consult with a pest control professional experienced in bird control. Working together, you can ensure you remain in compliance with these regulations.
The first step in preventing bird problems in a food facility is utilizing a pest control professional to conduct a thorough inspection of the building in order to determine if there are signs of birds, what species might be causing problems, and if there are any points of access birds could use to enter the building. The pest professional will closely inspect both the inside and outside of the structure with flashlights and mirrors to determine if changes should be made to better exclude birds. During this initial inspection process, it is crucial to have open communication between the service provider, the property owner, and building employees.
Because pest professionals only see a small window of activity, staff members who are present throughout the day are an invaluable resource for gaining intel on when and where pest birds are causing problems. The facility manager or owner must also be highly involved in the inspection and monitoring of pests so it is clear what vulnerabilities may be present in or around the structure, and what must be accomplished to eliminate them. Additionally, it should be noted that employees frequently contribute to the entry of pest birds into buildings and warehouses when exterior doors or windows are left open. Having a protocol in place that everyone is aware of and follows goes a long way in preventing birds and other pests from entering the structure.
That being said, birds are incredibly resourceful creatures and can enter buildings in a variety of ways. Any openings to the building, such as lofts, vents, or eaves must be blocked with wood, metal, glass, masonry, or plastic netting. Warehouse doorways used frequently throughout the day are common access points for birds. Installing clear plastic strips that touch the ground at the opening have proven effective at excluding birds, as these are seen by many bird species as impassable barriers.
Sealing the exterior of a structure and eliminating food or water sources in the immediate vicinity of the building are the best ways to prevent infestations. These types of methods, which focus on eliminating factors that could lead to pest problems before they take root, are part of an integrated pest management plan, also known as IPM. Frequently, these simple fixes are enough to manage pest birds.
Tactile, Auditory, and Visual Repellents
Equally important to excluding birds from entering the facility is eliminating roosting areas on top of or near the building. If possible, eliminate ledges or create a 45-degree slope on which birds will not be able to roost or nest. If this is not an option, there are three main types of repellents designed to affect a bird’s senses: tactile, auditory, and visual.
Tactile repellents make an area inaccessible or uncomfortable for birds to touch. Anti-roosting devices such as porcupine wire, which consists of rustproof spikes or needles, stainless steel wire coils, or toothed repellent strips are cost-effective options that may be installed to prevent birds from being able to land on ledges and windowsills. It is crucial that the material covers the entire length of the ledge, and any debris that could protect birds from the spiked effect must be removed on a regular basis. Electrical wiring is another option, which delivers a non-lethal shock when birds land. However for large areas, this may not be as economical a tactic as other aforementioned methods.
There are also chemical tactile repellents available to prevent roosting, which come in the forms of gels, pastes, sprays, and more. The textures of these repellents can vary widely, but they typically produce an uncomfortable sensation on birds’ feet when they land. These chemical repellents lose effectiveness over time, so reapplication may be necessary as often as every few months, depending on the variety. From an economic standpoint, chemical repellents are best suited for use in small areas.
Auditory repellents are sonic devices that emit intermittent noises that are frightening to birds. These devices use sudden, loud, or alarming noises such as screeching sounds, piercing alarms, and horns to scare birds away. Others use bird distress calls, which are especially effective for species that migrate in flocks and communicate threats to each other. These types of devices usually do not have a permanent effect on birds that are adapted to urban life, such as sparrows and pigeons, but can prove effective against large flocks of starlings and geese. Sonic devices should be installed as soon as birds begin roosting in an area because the longer a flock is established, the more difficult it is to drive the birds away with scare tactics. Noises should be employed in early morning before birds leave roosting areas and again at dusk when they return. Auditory devices, however, are not practical for urban or residential areas and may be regulated by local ordinances.
Similar to sonic devices, visual repellents are installed with the purpose of scaring birds away from an area, though some birds may quickly become acclimated to them, rendering the visuals ineffective. Lasers are one of the most effective visual repellents, and create intense red laser spots, which scare roosting or loafing birds and disperse flocks. Other visual repellents include flashing lights, fake owls, hawks, dogs or other threatening predators, and shiny flags. Like noise repellents, visual repellents are less effective on entrenched bird populations.
The Bottom Line
Proper bird control can take a lot of trial and error, as the effectiveness of each method varies depending on a facility’s location, its structural design, and the species of pest bird causing problems. Working closely and communicating openly with a pest control professional, and properly and promptly following their recommendations, will expedite the process of determining which bird management tactics are the best fit for a facility. Once an effective, efficient, and maintainable bird control system is in place, however, the many risks of food contamination associated with birds will be eliminated.
Dr. Fredericks is chief entomologist and vice president of technical and regulatory affairs for the National pest Management Association. Reach him at email@example.com.