Pigeons

Common names: Pigeon / Starling / House sparrow

PIGEON
Common Name: Pigeon / rock dove
Scientific Name: Columba livia

Biology.
Adult body length: 11 inches
Adult body weight: 13 ounces
Egg incubation period: 17 to 19 days
Broods per year: Several
Brood size: 1 to 2 eggs (usually 2) per clutch
Birthing Period: Peak in spring and summer
Age at which young leave nest: 4 to 6 weeks
Activity seasonality: year-round
Primary diet: Seeds, grain, livestock feed, livestock manure,
discarded food

Pest status. The feral pigeon adapts well to urban environments and is the most troublesome bird pest in urban settings as well as in small rural communities. The abundance of shelter provided by the design of many buildings assures that pigeons will have ample places to roost, loaf, and nest. Food and water is often in adequate supply, but when it isn't, the birds seek these necessities from nearby rural or undeveloped areas which are generally within flight range.
Pigeon droppings deface and accelerate deterioration of statues, buildings, and equipment and foul areas where people may walk or work. Pigeon droppings and nests clog gutter downspouts and air intakes, mar window sills, and render fire escapes hazardous. Their droppings and feathers can contaminate large quantities of livestock feed and food destined for human consumption.
The serious and constant public health problems they create are unmatched by any other bird species. They are known to carry or transmit pigeon ornithosis, encephalitis, Newcastle disease, histoplasmosis, cryptococcosis, toxoplasmosis,
pseudo-tuberculosis, pigeon coccidiosis, and salmonella food poisoning.
Pigeon ectoparasites include a number of bugs, fleas, ticks, and mites, some of which bite people (e.g., northern fowl mite).

Exclusion. The best permanent solution to nuisance birds that roost or nest in or on buildings is to build them out by making the site bird-proof. This is easily said but often difficult to accomplish. Building porticoes and balconies, exposed rafters on overhanging dock roofs, bridge bracings and other large, sheltered and recessed expanses, can be excluded using fine mesh plastic and polyethylene bird netting. Smaller recessed areas in structures (e.g., dormer corners and louvers of intake vents) can be screened with galvanized 1/2 inch mesh hardware cloth or boxed-off using sheet metal (e.g., aluminum coil stock) in situations where ventilation is not an issue. Similarly, starling and sparrow nest entry holes in hollow posts should be capped with 1/2 inch mesh hardware cloth or sheet metal. Once birds and nesting materials have been removed from soffits, dryer and exhaust fan ductwork, vents should also be screened over using 1/2 inch mesh hardware cloth or expanded metal sections cut to size.

Harassment and intimidation. Nest destruction can be helpful in preventing pigeon populations from increasing, but to be effective the nest and eggs must be destroyed at two-week intervals. Nest removal is most effective when used in conjunction with other types of reductional control. By itself, unless carried out over a very long period, it has little effect on localized pigeon populations. To be efficacious, nest destruction must be continued until natural mortality accounts for the surviving adults.
Because the breeding period of sparrows is an extended one, the systematic destruction of nests and eggs at 10- to 12-day intervals will reduce reproduction and may eventually move the birds from a building. However, recolonization by evicted sparrows, as well as new arrivals, often will occur on buildings previously cleared unless some other corrective action is taken.
Starlings can be repelled from night roosts with recorded starling distress calls. For best results, such distress calls should be initiated as soon as the birds begin using the location and should be continued until they leave. Three to four consecutive evenings is generally adequate to displace the birds to another roost, hopefully less objectionable. However, if after six to seven days, the birds have not moved, the technique should be reevaluated or discontinued. Scaring must begin early in the evening when the birds first begin to arrive and when there is sufficient light for the starlings to find alternate roosts. When repelling large numbers of starlings, a risk always exists that the new or alternative site selected by the birds will also be objectionable to humans.
Most visual devices (e.g., raptor silhouettes, plastic owls, rubber snakes, scare-eye balloons, Mylar/metallic-reflective tape, various reflective objects moved by breezes, flashing lights and the like) and auditory-based devices (e.g., electronic distress call emitters) commonly used for scaring away nuisance birds are of only temporary value at best. The longer a roosting site is used, the more difficult it is to displace the birds.
Repellents, deterrents and barriers. Clusters or arrays of sharp pointed wires, anti-landing projections, such as wire or plastic prongs, sheet metal spikes, and looped wire have proven to be effective as physical barriers in preventing pigeons and other birds from perching on building cornices, ledges and beams. The temporary discomfort inflicted by the spikes or the inability of the birds to light causes the birds to avoid these surfaces. Several kinds of these devices are commercially available in strip form that can be installed by Rottler technicians. Porcupine wire or strips of sharp projections can be permanently installed on ledges, rafters, window sills, or other locations where birds might roost, loaf, or nest. Wide surfaces may require two or more parallel rows of projections. The expense of the devices and their installation can be substantial but their permanent efficacy often justifies the cost.
Nuisance birds also can be discouraged from landing on ledges by installing thin wires supported by short posts and pulled taut by small springs. The wires are installed at varying heights spaced 3 inches apart across the width of the ledge. Likewise, pigeons can be kept from roosting on support cables, pipes, and narrow beams by stretching taut a piano-type wire about an inch or two above the item or surface. This wire is too small for them to light on and prevents them from perching on the surfaces beneath.
Installation of insulated electrified wires on roosting surfaces can be highly effective in deterring nuisance birds from landing. The wires carry high voltage but low amperage current similar to cattle-type electric fences and intermittently shock the birds without killing them. This measure offers a long-term solution in keeping pigeons off building ledges. However, such installations are not without some problems, for they can be shorted out by accumulations of dirt on insulators and by sticks and debris which may fall on the wires.

Live-trapping. Live-trapping of pigeons is not a method employed by Rottler technicians, but can be a very effective method of control. A variety of traps have been used, including loft traps, funnel traps, and bob-type walk-in traps. With few exceptions, the bob-type trap is the most effective. The size of these traps varies considerably, from being several feet in each dimension, to only 10 inches high and 18 to 24 inches in width and length. Regardless of size, the bob-type traps all work on the same principle. The door or entrance through which the pigeons are lured consists of a row of evenly spaced, one-way, free-swinging wire pieces (bobs). The bobs allow pigeons to push them upward and inward to enter the trap but prevent their exit. Grain (e.g., wheat, milo, or cracked corn) is scattered at the door entrance to entice the birds into the trap. One to three live decoy pigeons in the trap greatly improve trapping efficiency. Water and food have to be provided for the decoys. Live-catch traps should be serviced frequently to remove captured pigeons. Various methods are used for disposing of trapped pigeons, but in no case should they be taken away from the area and released, for the pigeon's homing ability can defeat any trapping and release program.

Chemical Control Repellents. Several polybutene caulk-type sticky repellents are available for application to ledges and beams where nuisance birds may roost or nest. These non-toxic tacky materials are designed to cause the birds to avoid the treated surfaces but not entrap them. The material is applied in closely-spaced wavy beads on the edges of roosting surfaces. While the gel form is the most popular, some tacky repellents are available in viscous liquid form to be sprayed or brushed onto surfaces. Small squeeze tubes and aerosol cans are also marketed for convenient application over relatively small areas. Even though they effectively repel birds in many situations, a drawback of sticky repellents is the likelihood that dust, falling leaves, and other airborne debris will soon coat the treatment, creating an unsightly mess and negating the repellency of this measure. Some are also adversely affected by temperature extremes . Certain brands of sticky repellent are formulated to be misted with a chemical top-coating that resists adhesion by leaves and other debris. Reapplication of sticky repellents is usually necessary in order to maintain maximum effectiveness.

Hallucinogenic and toxic baits. The hallucinogenic frightening agent AvitrolTM (4-aminopyridine) is available as a bait or concentrate and is quite effective for pigeon control. Avitrol is lethal to the birds that ingest sufficient quantities, but prior to death, the affected bird, depending on the species, may display erratic behavior and emit distress cries that, in turn, frighten the other birds of the flock. The treated bait is diluted with clean grain to limit the number of birds that will actually consume a biologically active dose. In this way, by dosing a relatively small number of birds, the material is capable of producing flock-alarm reactions which repel the rest of the birds from the area. The dilution rate used has a significant influence on effective results. Pre-baiting with whole corn or corn chops is essential to establish pigeon flock feeding behavior prior to baiting with treated grain. Repeated application of bait may be required until the population ceases to return to the area or until an acceptable population level is attained. After an initial success, bait need only be applied on-site periodically, following prebaiting, to keep pigeons from returning.