Collisions between birds and aircraft have caused damage to, or destruction of, aircraft and loss of human life for more than 68 years. Birds are attracted to airfields by the large open spaces which they provide and, often, by the availability of food, water, and shelter, on or near the airfield. Birds attracted by open space can be driven away by trained persons furnished with suitable bird-dispersal equipment, while removal of food, water, and shelter, can reduce the attraction.

Mass movements (migrations) by birds, especially large birds, create hazards for aircraft aloft. Air traffic control radar can show the abundance, speed, and direction of movement, of birds, while correlation of those movements with weather parameters permits development of bird movement hazard forecasts. Although the periods of high hazard are of short duration, use of these forecasts to make changes in flying training programmes has reduced losses of Canadian military aircraft through bird studies.

Automatic digital presentation of bird movement data gathered by radar has been tested at two airfields by air traffic controllers for possible use in vectoring scheduled civil aircraft away from hazardous concentrations of bird migrants. A decision on operational use of the technique has not yet been made.

Reduction of bird hazards to aircraft depends upon human motivation. The necessary habitat control, bird dispersal, and migration hazard forecasting, involve timeconsuming, rather dull work that is repeated at prescribed intervals. Unless the work is always well done, bird-strikes on aircraft will continue and human lives and aircraft will be lost.