Heavy infestations on buildings can create large amounts of fouling and make buildings look unsightly, the fouling is also very acidic and causes damage to the fabric of buildings, which in turn leads to higher cleaning and repair bills.

Bird fouling has the potential to make walkways slippery, causing a health and safety hazard.

Nests can block gutters and downpipes, and potentially damage plant on rooftops, such as air conditioning units.

Feral Bird fouling is also extremely hazardous material. Micro-organisms within the fouling are carriers of many pathogenic diseases, some are detailed below.

Extrinsic Allergic Alveolitis: More commonly known as pigeon fanciers lung, this is a serious allergic state that cannot be remedied, while any associated bird matter

(fouling, feathers, or nesting materials ) is present.

Salmonellosis: This bacteria is passed on to humans via the birds’ droppings, contaminated feathers and nesting materials. It is estimated that over 68% of the feral pigeon population carries Paratyphoid strains of the Salmonella bacteria.

Histoplasmosis: The yeast fungus ( Histoplasma capsulatum ) which causes this infection grows in the surface soil in many parts of the world. The spores thrive in bird fouling. Humans contract the disease by breathing in the spores. Symtoms are loss of appetite, diarrhoea and liver enlargement. Diagnosis is by blood test or by growing the fungus from sputum specimens.

Crytococcosis: A very serious illness which begins as a lung infection and can progress to attack the meninges and manifest itself as meningitis.

Erysipelas: Since the introduction of penicillin, it has become very rare. It is a very serious type of wound infection. It is however still possible for anybody in close proximity to birds to be attacked by virulent strains of streptococcus pyogenes which enter through minor open wounds.

Campylobacter: This illness manifests itself as a severe case of food poisoning Campylobacter enteritis. Contamination from the campylobacter jejuni is also known to be transmitted by Corvids such as magpies pecking at milk bottle tops and contaminating the milk.

Chlamydiosis: Relates to two similar diseases which are both influenza type viruses: (1) Ornithosis, the vector is a bacterium, Chlamydia psittaci, (2) Psittacosis, the closer of the two to a typical pneumonia. The young and the elderly are particularly at risk.