Originally descended from the wild Rock Dove, a cliff-face dweller, these birds find the next best thing is a block of flats, a bit of Victorian Gothic architecture or a railway arch. In the absence of natural predators, birds which fall sick survive to infect healthy ones with ornithosis and other diseases, some of which can be transmissible to man.
There are 3 diseases known to be associated with pigeon guano:
- Psittacosis – bacterial disease that spreads when guano dries and guano particles become airborne and are inhaled.
- Histoplasmosis – fungal disease that grows in the droppings
- Cryptococcosis – fungal disease that grows in the droppings
All 3 are zoonotic and represent a risk to human health.
Feral pigeons foul buildings, creating unwanted stained windows and architecture. All sorts of pests will migrate from their nests into buildings.