Bird control is the generic name for methods to eliminate or deter pest birds from landing, roosting and nesting.
Bird control is important because pest birds can create health-related problems through their feces, including histoplasmosis, cryptococcosis, and psittacosis. Bird droppings may also cause damage to property and equipment. Birds also frequently steal from crops and fruit orchards.
Methods of bird control include physical deterrents, visual deterrents, chemicals and sonic/ultrasonic devices, contraceptives, trained birds of prey (falconry), active barriers, among others. Birds usually adapt quickly to most static bird control devices. The bird 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. Unlike bird spikes which can pierce and impale the birds, the "shocking" and "blocking" products will not harm birds, they are simply designed to repel birds from an area. The Humane Society of the United States (HSUS) recommends the use of bird netting, wire, contraceptives and low-current electric barriers. Bird control products are used widely throughout the U.S. and the world.
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 allowed everywhere.
Sonic bird 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.
Ultrasonic devices are designed for enclosed or semi-enclosed areas with some success. Ultrasonic waves prevent birds 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.
A lightweight, spinning turbine, propelled by wind, and reflecting sunlight, has also controlled nuisance birds due to its random action. Birds frequently become acclimated to the device as the birds learn the device is not alive.