We love our birds but sometimes they are a bit too much. They can get messy when they poop on our sidewalks, roof, golf course, boat, or car. They can build nests in the most inconvenient of places like on our windowsill, porch, or potted plant. They can damage crops, endanger airplanes, and peck on our wood siding. They also carry diseases although, with the exception of the bird flu and West Nile Virus, it’s not a serious issue.
So what do we do? First, realize that in North America, virtually all birds, except the imported House Sparrow, European Starling, and Rock Pigeon are protected by federal law, the Migratory Bird Treaty Act. So if woodpeckers are damaging your house, you cannot simply shoot or poison them, or even try to scare them away by throwing rocks, as that might injure them.
According to Wikipedia, with modifications,
“Methods of bird control include physical deterrents, visual deterrents, sonic devices, trained birds of prey, chemicals, contraceptives and active barriers, among others. Birds usually adapt quickly to most static bird control devices because the birds adapt after exposure to false threats. The avian control devices that are most effective either physically “block” the birds or “actively modify behavior” using a mild harmless shock.
Physical bird deterrents include such products as steel or plastic spike systems, bird netting, electrified wire systems, non-electrified wire systems, electrified track systems, slope barriers, mechanical spiders, chemical foggers and more. Sharp bird spikes can pierce and impale birds, while “blocking” and “shocking” methods do not harm birds. Unfortunately, blunt tip bird spikes may still impale birds on windy days. The safer shocking and blocking methods simply repel birds from an area with no harm. The Humane Society of the United States (HSUS) recommends the use of bird netting, bird wire, contraceptives and low-current electric barriers. Many different bird control products are used widely throughout the U.S. and the world with low current shocking wire and strips, netting, and mesh being the most effective bird control methods.
Chemical deterrents range from products for turf to avicides. There are taste aversion products for geese, and fogging agents used for birds. Many localities have restrictions on the use of chemicals and pesticides targeted at birds if they intend to kill them. Chemical deterrents that do not harm birds are widely used with limited results.
Sonic avian deterrents are used widely in large open areas although effectiveness is low. Sounds are audible, and include predator and distress calls of a variety of birds to discourage pest birds from coming into an area. Common locations for these devices include vineyards, reclamation plants, airports, and other open areas. Sophisticated digital sound reproduction combined with random time off intervals, and random sequences are designed to prevent habituation by birds, and increase long-term effectiveness. Studies have shown most avian species will adapt and ignore such devices within months of initial contact.
Other static sound methods with limited effectiveness that birds may adapt quickly to include ultrasonic devices . In theory, ultrasonic waves will annoy birds to stop them from entering and remaining in areas such as warehouses, parking garages, and loading docks. These products are not harmful to birds, yet it is debatable if the birds can hear these frequencies . Studies have shown effectiveness is very low within months of initial contact when using ultrasonic sound generators .
Audible bird scarers can easily become ineffective bird control solutions, however when managed on an ongoing basis or used as part of a greater bird deterrent system, sound methods can deliver partial results for low level bird activity. Audible bird scarers are totally ineffective for nesting birds.
Wind driven scare devices include tapes, balloons, kites, and lightweight spinning turbines propelled by wind. These devices reflect sunlight and in limited uses scare birds that are new to an area. Typically, birds will quickly become acclimated to such devices as the birds learn the devices are not alive. The latest field testing of sonic colored noise shows the birds habituate after a few months even though the sounds are unnatural. This is because as one bird habituates other birds may learn the noise is meaningless and not a real threat.
Normally, birds adapt within weeks of exposure to bird control devices that are not alive or an actual threat to their survival. Such bird control devices that birds habituate to within weeks include sound devices, mechanical devices, wind blown scare devices, and partial perch modifications. This makes such devices an unwise investment even though they are inexpensive because labor and safety costs are the primary factors in bird control installation. In contrast, birds cannot adapt to total “blocking” methods or mild electrical low current “shocking” stimuli that modifies behavior. This is why netting, mesh, and low current electrical barriers are tested to be the most effective avian control devices. High quality materials and long lasting systems have the greatest return on investment because bird problems are perpetual year after year.
In 2013, Dr. John Swaddle and Dr. Mark Hinders at the College of William and Mary created a new method of deterring birds and other animals using benign sounds projected by conventional and directional (parametric) speakers. The initial objectives of the technology were to displace problematic birds from airfields to reduce bird strike risks, minimize agricultural losses due to pest bird foraging, displace nuisance birds that cause extensive repair and chronic clean-up costs, and reduce bird mortality from flying into man-made structures. The sounds, referred to as a “Sonic Net,” do not have to be loud and are a combination of wave forms – collectively called “colored” noise – forming non-constructive and constructive interference with how birds and other animals such as deer talk to each other. Technically, the Sonic Nets technology is not a bird scarer, but discourages birds from flying into or spending time in the target area. The impact to the birds is similar to talking in a crowded room, and since they cannot understand each other they go somewhere else. Early tests at an aviary and initial field trials at a landfill and airfield indicate that the technology is effective and that birds do not habituate to the sound.”