Pigeons measure between 12 to 33 inches (30 to 84 cm). Most pigeons have round or square tails. Many members of the family have red or pink feet. The bill is slender and rounded, and is usually short, with a fleshy growth at the base. The plumage is thick with metallic glints, and varies in appearance from browns and grays of many temperate-zone species to the bright hues and bold patterns of tropical forms.
Pigeons have color vision, a hearing range very close to that of humans and have poor senses of taste and smell. Pigeons cannot think, but are capable of conditional learning.
There are 4 behavioural habits requiring consideration. These are feeding, nesting, roosting and loafing.
Pigeons prefer to feed on seeds, grain, fruit etc. However, they will feed on garbage, animal matter, livestock manure and many other foods when their preferred foods are scarce.
Nests are loosely constructed and usually consist of sticks, leaves and other debris. They are built on ledges of structures, cliffs or in caves. The considerable amount of cliff-like nesting sites, especially on older buildings, is one of the key factors that attract pigeons to cities. Often nesting and roosting occur in the same general area, but they can be distant.
Roosting sites are where pigeons rest or sleep. They usually involve some kind of perch that is often high off the ground such as exposed roof girders, protected ledges, etc. Loafing is loosely defined as when pigeons are not feeding, nesting or roosting. This may occur almost anywhere pigeons are not constantly disturbed.
Pigeons have very acidic droppings which can deface marble, limestone, painted surface, statues, car finishes, etc... Fresh droppings can cause objectionable odours and slippery situations on sidewalks, roads, fire escapes and other flat surfaces. Droppings, feathers and nesting materials can contaminate unprocessed grain and packaged foods. Pigeons also have diseases, ectoparasites and other pests associated with them.
Pigeon control or management begins with the most important step, the survey. The survey should address the following: location of problem, species observed (pigeons/non targets and numbers), habitat (food, water, nesting sites), special equipment, time constraints, analysis of problem, public relations issues, recommended control procedures and pricing considerations. The site should be visited on several days when typical/normal site activity and weather is occurring. On each day selected, 3 visits should be made (sunrise, midday and late afternoon) and observations should be recorded with date and time. Minimal equipment includes binoculars, bird field identification guide, watch, site plan or map and reference manual giving biology, habits and control.
Once the species involved (pigeons and non-targets) are determined via the survey, appropriate federal, state and local regulations should be checked. Pigeons are not protected by the federal endangered species act or migratory bird statutes, but they are protected in some states; if the area is a bird sanctuary, then local permits are also required.
Many options are available for bird control. There are 5 methods that do not utilize toxicants. The first is exclusion which involves structural modification (eg. Change ledge angle to 45 degrees), the installation of plastic netting, and/or the use of repellents such as plastic and metal spines, monofilament and steel lines, and gels and pastes. The second is sanitation which involves the reduction or elimination of feeding sites and temporary water sources. The third involves the use of sound devices such as noise-making devices (usually not suitable for urban areas). The fourth is trapping which can be effective if the birds are destroyed and not released; otherwise, they will return home or create problems elsewhere. Finally, shooting can also be effective for removing birds within some kinds of buildings.
There are 2 methods of control utilizing chemicals or toxicants. The first can be considered a chemical frightening agent and involves grain coated with a material that of the flock being repelled. Its use involves a prebaiting program and the entire cycle may have to be repeated if other pigeons move in; it may be lethal to glutton pigeons. The second method involves contact toxicant that is administered via strategically placed perches which have an absorptive wick along their upper surface.