Solving Pigeon Problems

09-30-2007, 02:25 AM

Solving Pigeon Problems

More and more municipalities are developing strategies for peacefully coexisting with pigeons. Effective management plans involve educating the public and, often, keeping pigeons out of certain areas.

Pigeon Facts

Pigeons, or rock doves, have been around for several million years. They have a life span of about 15 years and can sense the Earth’s magnetic field through the use of a magnetic “map” inside their beaks.

Pigeons pair for life, and both parents care for their young. Pigeons flock in large numbers to protect themselves against cats, hawks, owls and rats. Even so, up to 35 percent of a pigeon population may perish annually from natural causes and predators. Pigeons naturally stabilize their own populations in accordance with food supply and other factors.

Pigeons are very intelligent. “Pigeons commit new images to memory at lightning speed. …They organize images of things into the same logical categories that human beings use when we conceptualize.” (1) Return to top

The Myth of Disease

The most widespread misconception about urban pigeons is that they are carriers of disease. The truth is that the vast majority of people are at little or no health risk from pigeons. In fact, a child attending school is many times more likely to get a disease from another child than from neighborhood pigeons.

It is no surprise that pest control companies charge pigeons with transmitting histoplasmosis, toxoplasmosis, psittacosis, crypttococcosis, salmonellosis, meningitis, tuberculosis and encephalitis. Of these diseases, histoplasmosis and crypttococcosis are the only ones that could be linked to large bird populations, even though pigeons themselves are not infected with and are not carriers of the diseases. These fungi occur naturally in soil. When bird droppings mix with the soil over a period of years, they can enrich the soil in a way that favors development of airborne spores, and people who live near sites where pigeons roost may be exposed.

The symptoms of infection generally resemble a mild cold. People recover without medical intervention and develop a natural resistance against further infection. Much of the population has already been affected, developed an immunity, and never been aware of it. Histoplasmosis is rare in dry states because it requires moisture to grow. Salmonellosis and toxoplasmosis are more commonly contracted from undercooked, contaminated meat. (2)

There is no evidence linking the other diseases to pigeons. In fact, most of them are so common in nature, so rare in humans or so mild in their symptoms that pigeon control is pointless. Return to top

The Problem

Accumulated pigeon droppings can damage buildings, monuments and automobiles and may require professional removal. Further, some building owners complain about nests blocking drains or birds creating roof damage.

Removing the birds in question may seem like the obvious answer, but killing the birds is never a solution. The installation of barriers is not only humane, but is also less expensive
and more effective over the long term. Return to top

Humane Bird Control

Birds settle in areas that suit their needs. Therefore, an effective program of bird control consists of making the designated area as uninviting as possible through conditioning and exclusion. Building codes should be modified if needed to include provisions for bird proofing.

Conditioning birds to avoid an area through the use of noises, mirrors, etc., should be done as early as possible to effectively discourage them from settling in. It is important to vary the deterrents so the birds do not get accustomed to them. Don’t feed the birds, and eliminate food and litter from the area.

Open areas, such as vents, lofts or eaves, can be sealed to prevent birds from nesting in the holes. Openings in lofts, church steeples and other enclosed spaces can be screened with one-half inch mesh hardware cloth. Any such exclusion must be done when the birds are not inside.

Very simple modifications in a building’s structure can discourage birds from landing or nesting on the building. Steel, wood or stone angles on building ledges and light fixtures prevent pigeons from nesting. Birds can be discouraged from roosting on such flat surfaces by using boards or sheet metal to create a 45° or greater slope. The Randolph Center at Broadway and Walnut in Boulder, Colo., uses this technique effectively in its parking garage.

Bird barriers, such as a thin metal coil resembling a “slinky” toy, can be fastened to a building ledge to discourage birds from landing. Birds can be deterred from roosting on railings and pipes by installing Mylar™ tape streamers or a single strand wire barrier two inches above the center of the surface.

Netting can be used to exclude birds from virtually any type of structure, from a house to an office building. To keep birds off window ledges, the netting is anchored to the roof, draped across the front of the structure and then tightly secured to the base and sides of the building. Netting can be used under bridges or inside buildings where pigeons perch on beams, girders, struts and supports.

Ropel™, a foul-tasting deterrent, can also be sprayed on an area. Other deterrents include
soft plastic spikes, flood lamps and special electronic sounds. Companies such as Bird Barrier and Bird X offer many products to scare off or exclude birds from any area.

Scarecrows are often used to control birds. Models of owls, hawks, snakes and cats are also available from many suppliers and vary in effectiveness, depending on how realistic they are and how often they are moved. Return to top

Poison: Dangerous and Ineffective

Poisoning wildlife is cruel. Avitrol, a commonly used bird poison, causes suffering for up to 15 hours before death. (3) What’s more, humans and other nontarget species can die or become ill from accidental ingestion of or skin exposure to small amounts of bird poison.

In 2002, a little boy in Las Vegas brought home a pigeon he’d found who was dying of Avitrol poisoning. Shortly afterward, the family began to show poisoning symptoms, and the boy became very ill. In January 2003, a dog was reported poisoned in Aurora, Colo., after eating one kernel of Avitrol-laced corn. According to New York City’s Avitrol ban, “Avitrol is too deadly and too blunt an instrument to be used in an urban setting.”

Poisoning is unlikely to have any lasting effect on the number of pigeons in a given area. Population densities depend on the availability of food, space and shelter. If some pigeons
are killed, more will take their place, bringing the flock back to its original size.

According to the U.S. Fish & Wildlife Service, killing birds can actually create favorable grounds for breeding and can result in an increase in bird populations. Those who have traditionally hired exterminators to poison birds actually save money and frustration by switching to nonlethal methods. Return to top

How YOU can help

If you find a bird in convulsions or vomiting vomiting, or if you suspect that a bird has been poisoned, put the bird in a box and rush her to Greenwood Wildlife Rehabilitation Center Center in Lyons (303-823-8455). Another option is to take the bird to a veterinarian. About 50 percent of poisoned birds can survive with prompt treatment.

Use caution when handling the bird and avoid skin contact. Always report such birds to Boulder Animal Control (303-442-4030). If the bird dies, turn the body over to Animal Control.

Arty