By Garth Calitz

Birds and aircraft have been colliding with significant impacts on both humans and animals since the early days of aviation. The global aviation industry is increasingly acknowledging that bird strikes pose a significant safety threat. Birds are drawn to airport areas to feed or rest and frequently fly over these zones from their feeding or roosting locations.

Air traffic in South Africa is on the rise, making it crucial to uphold international air safety standards at South African airports. Historically, there has been minimal coordination in managing bird-related safety risks at these airports. To address this, the Airports Company South Africa (ACSA) has formed a unique strategic partnership with the Endangered Wildlife Trust (EWT), a non-governmental organization dedicated to conserving southern Africa's biodiversity. This collaboration aims to establish and operate a comprehensive national bird control program. The project's goal is to reduce bird strikes and other wildlife interactions with airport facilities at ACSA airports by employing environmentally sensitive management techniques.

Birds present a significant threat to aircraft, especially in and around airports (with 75% to 95% of bird collisions with civil aircraft occurring at or near these locations). Large and heavy species like gulls, vultures, and geese, as well as small flocking birds like starlings and swallows, are particularly dangerous. In recent decades, there has been a notable rise in the number and frequency of bird-aircraft collisions. This increase is primarily due to a rise in flight operations coupled with growing populations of certain hazardous bird species.

Birds are drawn to airports because they perceive the expansive airport grounds as a safe haven for resting, flocking, or evading predators. In addition to safety, airports provide birds with access to food and water for drinking and bathing. The presence of birds at airports is also influenced by the appeal of nearby habitats. To reduce the risk of bird strikes, various long-term and short-term strategies are employed. Long-term measures should be considered during the airport's planning and construction phase, such as building the airport away from significant bird areas and migration paths. The most effective strategies involve decreasing the environmental carrying capacity at the airport. This involves altering the ecological characteristics of the airport by removing water sources, food supplies, and shelters, making it less appealing to birds. Structural solutions and barriers that passively deter birds by making the airport infrastructure less attractive are also highly effective. These methods lead to a long-term decrease in the bird population at the airport, thereby reducing the risk of bird strikes.

These methods do not completely remove all birds from the airport operational area and should be complemented by various dispersal techniques. These techniques should include a mobile patrol equipped with acoustic devices (such as shell crackers and propane cannons), visual devices (like flares), and physical deterrents (such as trained birds of prey). Since no single technique is entirely effective, multiple methods should be employed together. Scaring techniques should be used selectively and rotated to prevent birds from becoming accustomed to them. The choice of bird-control methods depends on the severity and nature of bird-related issues. Therefore, it is crucial for airport staff to monitor bird presence and movements both at the airport and nearby, and to document all bird-aircraft collisions, noting their severity and the bird species involved. Analyzing the variation in collision risk based on time of day and year, as well as flight phase and altitude, allows for the adaptation of the bird management program to changing environmental conditions.