Health Hazards of Pigeons
Both humans and animals can be affected. The disease is transmitted to humans by airborne fungus spores from soil contaminated by pigeon and starling droppings (as well as from the droppings of other birds and bats). ... On occasion, the disease can cause high fever, blood abnormalities, pneumonia and even death.
Transmission of diseases such as histoplasmosis, cryptococcosis, and psittacosis (ornithosis). Attraction of ticks, mites, cockroaches and rats. Unpleasant odour and noise issues. Damage to buildings and monuments due to the highly corrosive nature of pigeon droppings. Extensive damage to air-conditioning units and other roof top machinery.
