Birds and the law
The law states that premises must be protected against external sources of contamination such as pests. Under the food and safety Act 1990, fines of up to £20,000 per charge can be enforced in the magistrate’s courts if pests on the premises threaten health or safety. If an immediate threat is posed, the premises can be closed on the order of the environmental health officer. If prosecution is taken on the Crown Court, the penalties include unlimited fines and up to six months imprisonment.

Structural damage
Bacteria and fungi present within the fouling secrete acids which cause staining, defaces buildings and damages stone, brickwork and metalwork.
Gutters become blocked with fouling, nesting material, feathers and carcasses causing water leakage or overflow.
Buildings are then frequently subject to water penetration and damage.
Buildings appear aesthetically unpleasant. Large accumulations of fouling form solid blocks of matter, which become dried, dense and heavy. These are often dislodged from the building by the birds and fall to the floor. Affected areas need continual cleaning, repainting and external repairs which all increase building maintenance costs.

Heath and safety
Bird fouling on paths and walkways is always a serious slip hazard. Obviously in heavily used areas, steeply sloping paths or in wet weather, the risk of an associated accident is greatly increased.
Whilst urban birds are only rarely implicated in specific instances of human disease, there are real potential risks associated with both dead and alive birds, their nesting materials and their fouling. Of most concern at present are the pathogenic microorganisms and the large number of biting and carrion insects that are likely to be present. In the warmer months especially, the bird fouling becomes dried and airborne and could be inhaled by any person in regular proximity to it, or could be blown into the building through open doors and windows, or could be drawn into the building’s air conditioning system.
Despite the consequences of inhaling any one of the pests detailed above, inhaling the fouling itself can cause very serious respiratory problems.

Noise and smell
The noise from urban birds can be extremely annoying and disturbing to the occupants of a building. The noise increases throughout the breeding season.
The combined smell of bulk fouling, rotting nesting debris, carcasses, urine and bacteria can be quite overpowering.