Bird control

The avian control devices that are most effective either physically "block" the birds or "actively modify behavior" using a mild harmless shock.

[2] 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.

Wind-driven scare devices include tapes, balloons, kites, and lightweight spinning turbines propelled by wind.

[9] According to the US Fish and Wildlife Service, a falconer may request any Migratory Bird Treaty Act of 1918 (MBTA)-protected raptor species that may be used for falconry except for golden eagles.

In contrast, birds cannot adapt to total "blocking" methods or mild electrical low current "shocking" stimuli that modify behavior.

For sonic units, long-term effectiveness increases with sophisticated digital sound reproduction played in random sequences and intervals.

Other static sound methods with limited effectiveness that birds may adapt quickly to include ultrasonic devices designed for enclosed or semi-enclosed areas.

In theory, ultrasonic waves will annoy birds to stop them from entering and remaining in areas such as warehouses, parking garages, and loading docks.

[11] Thus, studies have shown effectiveness is very low within months of initial contact when using ultrasonic sound generators to prevent birds from inhabiting an area.

[11] The latest field testing of sonic colored noise shows the birds habituate after a few months even though the sounds are unnatural.