Food handling facilities are sensitive environments where contaminants and adulterants must be carefully monitored and managed as the potential for causing human foodborne illnesses in large numbers of people is elevated. Birds and the accompanying contaminants and adulterants they bring are causes for great concern in, on, or around food facilities. A number of bird species, including pigeons, sparrows, starlings, seagulls, crows, swallows, and occasionally birds of prey, are often found at food facilities. Of these, the three non-native species, pigeons, sparrows and starlings, are responsible for the majority of bird problems at food establishments. These birds have adapted extremely well to man-made environments and they have become extremely resourceful at exploiting sources of food, water, and shelter that are available to them as a result of human activities.
Pest birds carry and transmit a large number of animal diseases including diseases of humans, poultry, and other birds and animals. Pigeons, starlings, and sparrows have been reported to transmit over 60 diseases. Some diseases known to be transmitted by pigeons are pigeon ornithosis, encephalitis, Newcastle disease, histoplasmosis, cryptocococcosis, toxoplasmosis, pseudo-tuberculosis, pigeon coccidiosis and Salmonellosis. The possibility of the arrival this year in the United States of Avian Flu, has raised concerns about pest birds that live in close association with humans. The three common pest birds mentioned in this article have not been implicated in the transmission of avian flu, however, it has been reported that although pigeons are not easily infected by bird flu, they are not immune to it.
Bird droppings deface and accelerate deterioration of buildings, signs, parking lot light fixtures, equipment and other features in the landscape. Bird feces often foul areas, where people walk, sit, eat meals, rest, relax or work. Accumulations of bird droppings produce flies, airborne contaminants, fungus spores and detestable odors. Fouled stairways, fire escapes and other walking surfaces create slip/slide/fall hazards. Bird feces at entrances of buildings are easily tracked indoors where they can become airborne or foot-borne contaminants. Debris from birds, their feathers, their carcasses, and nest materials have clogged roof drains, gutters, and downspouts, and in some cases caused flat roofs to collapse because of a lack of drainage. Roof life of structures has been reported to be reduced by 50 percent or more by concentrated bird usage. Ectoparasites of pest birds include chewing lice, fleas, ticks, biting flies and mites, some of which can enter bird infested buildings and bite people. These arthropods can themselves inadvertently become food contaminants and adulterants.
Pigeons have been referred to as flying rats and when their behavior and associated problems are considered, this is a very relevant comparison. At food facilities, bird infestations should be treated with the same degree of concern and urgency as rodent problems.
Rats are often found at locations where pigeons have been nesting, roosting and raising young for extended periods of time. At these sites, rats will feed on pigeon eggs, young birds (squabs) and pigeon carcasses.
Managing Pigeons, Starlings and Sparrows
Before embarking on any bird control program, detailed survey, scouting and monitoring must be conducted. The bird or birds causing the problem must be positively identified as control strategies will vary from species to species. Occasionally, unusual birds may be found at some facilities and they may be classified as protected species and covered by federal, and in most cases, state laws. Migratory birds are protected under the Migratory Bird Treaty Act of 1918 (16 USC 703-711), while non-migratory species are protected under state laws. Some species are further protected by the Endangered Species Act of 1973 (as amended) (Pub.Law 93-205). These laws make it unlawful to pursue, capture, take, kill or possess migratory birds or endangered and threatened species, except as permitted by regulations adopted by the Secretary of the Interior. Permits to take non-endangered migratory birds are issued only when the birds are causing, or have the potential to cause, a serious threat to public health and safety and when non-lethal methods have failed to solve the problem. A state permit may also be required to control migratory and non-migratory birds protected by the state.
Observations should be conducted on different days and different times of day in order to develop an understanding of the behavior and movements of target birds. Binoculars may be needed to scan high places such as ledges, windowsills, roof edges and high roof overhangs of tall buildings. When inspecting for birds at food facilities, the roofs of buildings should be inspected where possible as it is common to find pigeons nesting, roosting and loafing, on, under, and around heating, ventilation, and air conditioning units on roofs. From these locations, bird contaminants and adulterants can enter the air handling systems of a structure and be distributed throughout a food facility.
A variety of management options are available for addressing bird problems at food facilities. These include:
Prohibit Bird Feeding
Management must establish and enforce a clear written policy prohibiting people from feeding birds at food facilities. Pest birds are creatures of habit and they will return to a site where they are fed on a regular basis.
Eliminate Water Sources
Avoid or minimize unnecessary use of water outdoors so as not to provide pests with a critical survival resource. Repair outdoor water leaks, calibrate and adjust landscape irrigation systems so as not to cause runoffs that create puddles. Fix or repair low spots in landscapes and hardscapes that could catch and retain water. Clean and repair gutters and downspouts to prevent water accumulations and facilitate drainage. Bear in mind that standing water is an ideal breeding site for mosquitoes that transmit West Nile Virus. Crows and other members of the corvids (the bird family c) are excellent reservoirs of West Nile Virus.
Good sanitation practices, such as prompt removal of unwanted food, food debris, food wrappers and food containers, will go a long way towards reducing the attractiveness of an area to birds. If employees consume food outdoors, it is important that everyone clean up after themselves or someone be designated to promptly clean these areas. Adequate numbers of covered trash containers should be provided for disposal of unwanted materials. Trash receptacles should be emptied and cleaned on a regular basis so that odors emanating from them do not attract flies, ants, and other pests.
Physical Bird Deterrent Devices
A large number of bird deterrent devices are available to dissuade birds from perching on certain locations of buildings. Two good sources of these materials are www.birdbarrier.com and www.birdbgone.com. Every situation is different and each may pose unique problems based on its location, etc. Thus, each must be assessed and evaluated, and materials that are cost effective and appropriate to that area must be carefully chosen. A good bird management professional should be able to provide expertise on smart, effective and economical choices of bird deterrent devices.
Places where pest birds are roosting, loafing, or nesting can be screened off with good quality bird netting of the appropriate mesh size to exclude these feathered creatures. Nets should be installed using quality installation materials and in a professional manner so that they do not become an eyesore and detract from the aesthetics of the facility. Professionally installed bird nets, can in some cases, actually complement and enhance architectural appearance of structures.
Pointed spikes can be installed on surfaces, including pipes, on which pest birds perch. These spikes prevent birds from landing but do not harm them. Bird spikes are available in different materials and configurations and the appropriate ones have to be selected for certain situations. Polycarbonate bird spike can be obtained in colors that match the color of a structure. On ledges and roof edges, proper spacing of spikes is important so that birds do not access and use areas between rows of spikes. Bird spikes should be inspected periodically to make sure that they are still in place and are not compromised by birds piling debris on them.
Narrow beams, long exposed ledges, parapets, signs, beams, pipes, roof edges, and other such areas can be protected with nylon coated spring-tensioned stainless steel wire attached to stainless steel posts and tensioned using springs. These wires are most effective on pigeons, seagulls, crows, and other larger birds. They are the least visible of the ledge products and they are often used in high visibility areas where aesthetics are important. These wires need to be professionally installed and properly spaced in order for them to be effective.
Bird-coil is available in four- and five- inch diameter, stainless steel coils of wire that expand out to 25 foot lengths. The five inch diameter coils are used for larger birds such as gulls. They can be installed on long, exposed ledges, parapets, signs, beams, pipes, roof top perimeters, etc. If more than one coil is needed to cover an area, the coils should not be spaced more than one inch apart. The outer edge of a coil should project about one-quarter inch beyond the edge of a ledge. Bird coils are fairly easy to install and when properly deployed, they are simply hindrances to birds being able to land on a surface. From about 50 feet away, they are invisible to the human eye.
Electric Bird Abatement Systems
Bird shock track systems can be used on roof tops and other areas not readily accessible to people. They provide a humane intermittent shock to discourage birds from landing on areas where they are installed. These are low-profile flexible tracks that are adaptable to architectural configurations and are available in four colors. Tracks are glued to surfaces that need protection and electrical connectors allow current to flow from one track to the next. Some of these tracks have a five year warranty. Proper installation and spacing are critical to maximize effectiveness. These systems require periodic maintenance as dirt, sticks, leaves, snow, and other miscellaneous debris can negate their effectiveness.
Angle ramps are sold under various trade names, such as BirdSlide, by different manufacturers. The basic principle on which they are based is that pigeons cannot land, roost, or build nests on surfaces with a 45-degree or steeper angle. Angle ramps can be installed on ledges and beams to deny birds access to the area. Where appropriate, they are good long-term solutions to localized bird problems. They are available in different colors to match the color of a structure.
Bird Scare Devices
A number of bird scare devices are sold in the marketplace to frighten and scare off unwanted birds. These include plastic owls, bird jumpo, scare-eye balloons, scare-eyes with streamers, Mylar flash tape, rubber snakes, etc. These may look cool and cute, but none of them are effective, as pigeons in particular, quickly become habituated to them.
Long Flexible Wires
Long flexible wires are sold under various trade names such as Daddi Long Legs and Bird Spider. These are long, slender, stainless steel rods that are attached to a base and extend out four, six, or eight feet. There are plastic tips at the ends of the rods to prevent injury to birds, people, and other non-target species. These rods rotate in the wind and wave menacingly thus interfering with birds as they attempt to land. These devices are fairly inconspicuous from short distances and practically invisible from 50 feet or more. They can be used in high visibility and high profile areas such as on top of parking lot lights.
There are several brands of non-toxic sticky repellent gels on the market that are sold as bird deterrents. These can be placed on edges and ledges to deter birds from landing there. They are gummy materials and birds simply do not like to get sticky materials on their feet. Surfaces have to be properly cleaned and prepared before gels can be applied. Dirt and debris will cover gels and eventually render them ineffective. Some gels will melt in hot weather and become hard and ineffective in cold weather.
The best and most permanent solution to pest birds entering and nesting within structures is to bird-proof the building to the fullest extent possible. Birds entering through openings to nest or roost within a building’s attic, false ceilings, etc. should be removed and the accesses closed off with durable materials. People working or entering confined spaces that were inhabited by birds should wear proper personal protective equipment due to the possibility of pathogens being present in accumulated bird droppings. Piles of bird droppings in, on or near food facilities should be removed and the areas disinfected using appropriate cleaning compounds and disinfection procedures. Cleaning, removing and handling of bird feces at food facilities should be regarded as being on the same level as working with hazardous materials and the same precautions should be taken.
Pest bird nests in, on, or in close proximity to food facilities should be removed and the area properly cleaned and disinfected. The site should be screened off so that birds cannot nest there again. Bird nests contain bird feces, animal debris, feathers, plant materials, ectoparasites, and more importantly, stored product pests. Insect inhabitants of bird nests frequently enter buildings where they often become stored product pests and nuisances. Those who remove bird nests should wear proper protective equipment. Bird nests on structures are often in high places and it may require the use of tall ladders or aerial lifts to access and remove them. The use of the aforementioned equipment requires adequate, documented training and perhaps this type of work should be left to professionals.
Live trapping can sometimes be a useful control strategy especially for pigeons. However, it is not an effective stand-alone control method especially when large numbers of birds are present. It is time consuming and labor intensive because traps must be monitored and serviced frequently for efficiency and humane purposes. The California Penal Code section 597 states that failure to provide trapped animals with “proper food, drink or shelter or protection from the weather is a punishable offense.” In many areas of the country, disposing of trapped pigeons is a major problem and birds taken to animal shelters are often released. Pigeons have excellent homing abilities and they will return to where they were trapped even when released far away from trapped location.
A flock-frightening chemical is available for bird management in the structural pest management arena. When consumed in certain quantities, this material can cause bird mortality. There are a number of negative issues that are associated with the use of avicides for bird control and these are addressed elsewhere. The public view all birds as desirable animals and they tend to respond negatively to bird mortality even that of filthy, disease carrying, non-native bird species such as pigeons, sparrows and starlings that often out-compete and displace native songbirds. In view of this, any time bird abatement programs involving avicides are contemplated, extremely careful considerations must be given to unintended consequences. Only licensed, trained, and experienced professionals should be trusted to use avicides. All label directions for avicides must be clearly understood, adhered to, and followed.
Pest bird control at food facilities must be based on an integrated pest management approach. Each facility should be carefully assessed and evaluated, and control strategies must be tailored to that location. One-dimensional approaches to pest bird management at food facilities are doomed to fail. Reliance on physical bird deterrent devices alone will not produce the desired results. Bird spikes, bird coils, bird wires, etc. simply move birds away from areas where they are installed to other areas of the property. They do not induce pest birds to leave a location where all of their life requirements are met on a daily basis. Therefore, a well balanced approach, utilizing a variety of control techniques, tools, and strategies, is the most efficient, cost effective, and long term solution to bird problems at food facilities.
- Gulmahamad, H. 2003. School Days. Pigeon problems at inner-city schools in Los Angeles cause trouble for students, teachers, and pest management professionals.
- Pest Control Technology 31(10): 146, 148, 149, 153, 154.
- Weber, W. 1979. Health hazards from pigeons, starlings and English sparrow. Thomson Publications, Fresno, California. 138pp.
Hanif Gulmahamad, Ph.D., B.C.E., PCA, is an urban and structural entomologist and consultant based in Ontario, Calif. He can be reached firstname.lastname@example.org.