Exclusion of gulls (Laridae spp.) from attractive areas (garbage dumps, sewage discharge areas, drive-in theaters, catering establishments) near airports can significantly reduce gull use of airport surfaces and flightways used by aircraft.
Exclude gulls from limited resting areas such as window ledges and rooftops by covering the surfaces with porcupine wires (see Pigeons). Exclude them from large areas such as water reservoirs, cropfields, and landfills, by installing wire or plastic netting or suspending parallel steel wire (28-gauge [0.36 mm]) or nylon monofilament line (50-pound [23-kg] test) over the area. Wire or monofilament spacing may be 40 feet (12 m) for large gulls to 15 feet (4.5 m) for smaller ones.
Birds have long been excluded from ponds in which fish are raised by using heavy, easily visible wires. Use strong, fine steel wires (28 gauge [0.036 cm]) on long, parallel spans up to 80 feet (25 m) apart to exclude gulls from a water reservoir. Wires have been used successfully to exclude most herring and ring-billed gulls from garbage dumps. It was found that a wire spacing of 30 feet (9 m) worked if the food attraction was not too great. Fifteen-foot (6-m) spacing worked even with very abundant food. Successful exclusion of ring-billed gulls (L. delawarensis) has been reported from food service areas in Toronto by using widely spaced nylon monofilament lines. They used more closely spaced lines to exclude the same species from part of a nesting area used by more than 70,000 pairs of gulls.
The reason that gulls rarely fly under or between fine parallel wires is not clearly understood. Other birds, including pigeons, regularly fly under and between the wires. The fine wires and lines are almost invisible at 35 feet (10 m) or more and may not be easily seen by gulls as they spiral down to land. The avoidance reaction when the wires are seen is spectacular and may disturb other gulls enough to make them avoid the wired area.
Resources: (online)
Gull Control
