p>Identification | Biology | Damage ID | Management | Handling
Overview of Damage Prevention
and Control Methods
- Remove standing water
- Prohibit feeding of gulls
- Allow plants to grow at least 18 inches tall
- Secure dump and trash sites
- Remove or reduce nesting and loafing sites
- Control insects
- Porcupine wires or electric ledge products
- Plastic or wire mesh
- Suspend parallel wire or monofilament strands over area needing protection
- Biological, auditory, and visual frightening devices
- Daddy-long-legs devices on structures
- Avitrol® (check to see if currently registered for gulls)
- Methyl anthranilate
- DRC-1339 (Federal use only)
- Rocket or cannon netting over bait
- Coulson funnel trap set over nests with eggs
- Spotlight and net by hand at night
Other Control Methods
- Remove nests, eggs, and young
- Egg oiling or puncture
Damage Prevention and Control Methods
Control gulls as soon as they become a nuisance. Stop management activities during active nesting.
Reduce or eliminate food and water and nesting areas. It is not easy to reduce the availability of food, as gulls are adaptable and use a wide variety of foods. Food waste, fruit and vegetable crops, insects, earthworms, and other species of invertebrates and small vertebrates are potential sources of food that require careful control to reduce their availability. Communities should restrict the feeding of gulls. Municipalities may find it useful to modify or eliminate artificial feeding sites such as garbage dumps, landfills, fish docks, trawlers, food processing plants, sewer outfalls, and livestock feedlots.
Manipulate the height of grass by limiting mowing to discourage gulls from using airports, parks, and playing fields as areas for resting or loafing. A vegetation height of 18 inches may discourage laughing gulls, but herring gulls will not necessarily be discouraged unless the grass is higher.
Exclusion of gulls from attractive areas (e.g., garbage dumps, sewage discharge areas, drive-in theaters, and catering establishments) near airports can significantly reduce gull use of surfaces at airports and aircraft runways.
Exclude gulls from areas such as window and roof ledges by covering the surfaces with porcupine wires or electric-shock ledge products. Exclude gulls from large areas such as water reservoirs, crop fields, and landfills by installing wire or plastic netting or suspending parallel stainless steel wire (28-gauge) or nylon monofilament line (50-pound-test) over the area. The spacing of the wire or monofilament may be up to 40 feet for large gulls and up to 15 feet for smaller ones. Monofilament line will breakdown under sunlight. Birds can be excluded from aquaculture ponds by using heavy, easily visible wires.
Use strong, 28-gauge, stainless-steel wires on long, parallel spans up to 80 feet apart to exclude gulls from water reservoirs. Wires have been used successfully to exclude herring and ring-billed gulls from garbage dumps. A 30-foot wire spacing may work if the food attraction is not too great, and 15-foot spacing may work even with very abundant food. Widely spaced monofilament lines may exclude some gulls. Two-millimeter diameter stainless-steel fishing lines spaced at 7.5 feet may exclude ring-billed gulls from outdoor restaurants and ponds.
It is not clearly understood why gulls rarely fly under or between parallel wires. Other birds, including pigeons, regularly fly under or between wires. Wires and lines are almost invisible at 35 feet 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 area.
Daddy-long-leg devices that move by wind or battery power can be used to prevent gulls from roosting on roof-tops and other structures.
Gulls can be harassed by trained birds of prey, radio-controlled small aircraft that resemble falcons, and dogs. All frightening devices should be used by experienced, dedicated personnel.
Repeated use of frightening devices will not resolve damage problems by gulls over the long-term. Research has shown, however, that reinforcing frightening methods with lethal control, where legal, can substantially increase efficacy of frightening devices with less than 2% mortality in the flock.
Effective frightening devices for gulls include shotgun shells, shell crackers, gas-powered exploders, and broadcasts of distress and alarm calls. Most distress and alarm calls are species-specific, and may even be specific to local dialects. They must be used sparingly to avoid familiarity and are best used from a stationary source. Gulls first will approach the source of sound and will leave the area after 5 to 10 minutes. Shell crackers can be used to direct the departure of gulls. They are most effective when the birds are airborne and have begun to move away from the source of the sound. The use of ultrasound for controlling gulls has not proven effective and is not recommended.
Effigies, balloons, and specially designed kites can be effective in dispersing gulls for short periods of time. Gulls that are dead or gull decoys placed in dead-gull postures can be used, especially in conjunction with other frightening devices. Effigies must be realistic in every detail, and may be enhanced with distress calls.
Lasers are effective in dispersing flocks of gulls in low light or at night. To control birds at night, perform sweeps every 30 minutes. Use lasers with extreme care, and avoid inadvertently flashing laser lights at people. Birds will return during daylight.
Avitrol® (4-aminopyridine) was federally registered to frighten herring gulls feeding, nesting, loafing, or roosting near or in the vicinity of landfills, airports, and structures. Mortality is minimized by limiting the amount of bait that is offered. Avitrol® is a Restricted Use Pesticide, so only certified pesticide applicators may use this product. State and federal permits are required to use Avitrol®. Check current labels to determine if it can be used to frighten gulls.
Methyl anthranilate (MA) fogging can repel and disperse gulls from areas. Research on the use of ultra-low volume dispensers is ongoing. Applications also can be made to crops that are ripening.
Polybutenes can be used as a tactile repellent to keep gulls from landing on beams, posts, and other structural materials. Polybutenes lose their effectiveness as dust accumulates and renders them less tacky. Simplify clean-up by applying polybutene to removable tape rather than directly to permanent surfaces.
The toxicant DRC-1339 is a Restricted Use Pesticide registered in the US for the control of herring gulls, great black-backed gulls, and ring-billed gulls. Legal use of DRC-1339 is limited to personnel of the& USDA-APHIS-Wildlife& Services. The toxicant is mixed with bread and is placed directly on nests of gulls. DRC-1339 causes death by uremic poisoning. It is slow-acting and apparently painless.
Shooting has been used to deter gulls that habitually fly over airport runways (e.g., Kennedy Airport, New York) and individuals that prey on the eggs and nestlings of protected species (e.g., black-headed gulls in Norfolk, United Kingdom). Shooting is not very effective for reducing large colonies due to the relatively small number of gulls that can be shot at a time. Shotguns and rifles can be a highly selective and useful, however, under certain conditions. Federal and state permits are required.
Gulls can be live-trapped by several techniques, including rocket- or cannon-netting over bait.
A funnel trap, also known as a Coulson trap, may be set over an active gull nest to capture adults. Traps should be 22 x 18 x 12 inches (minimum) and constructed with 1½-inch wire-mesh.
The entrance funnel should extend to the height of the cage with the wire ends exposed to discourage escape attempts. Weave 10-gauge wire along the edges of the funnel for reinforcement. Position the trap so the funnel entrance is in line with the normal path the gull uses to attend to the nest.
At night, gulls can be removed effectively by spotlighting and netting. This method works best on dark nights with low ambient light.
Other Control Methods
Nest, Egg, and Young Removal
Removal of all nests, eggs, and young from a colony should be done every 2 weeks. These activities are time-consuming and labor-intensive. Gulls usually attempt to re-nest. Federal and state permits are necessary.
Several methods can be used to ensure eggs do not hatch, including puncturing, shaking, and spraying with or dipping in 100% corn oil. To prevent relaying, treated eggs must be returned to the nest and not be visibly damaged. Repeated trips to the nesting colony are required to ensure that all eggs are treated. A pesticide applicator’s license may be required in some states for egg-oiling.