Pigeons (Rock Dove)
Latin Name: Columba Livia
The rock dove or rock pigeon includes the domestic pigeon and fancy pigeon. Escaped domestic pigeons have raised the populations of feral pigeons around the world. Habitats include various open and semi-open environments, easily nesting on all types of building structures within urban environments. Pigeons use cliffs and rock ledges for roosting and breeding in the wild. Originally found wild in Europe, North Africa, and western Asia, pigeons have become established in cities around the world. Their diverse diet of scavenged human food, insects, as well as bird seed and bread fed by city dwellers allows them to thrive in cities like Toronto. The invasive species was first introduced to North America in 1606 at Port Royal, Nova Scotia. Pigeons cause structural damage to buildings and costly machinery, can contaminate food supplies and act as carriers of Salmonella and Chlamydophila psittaci and bacteria causing psittacosis, a rarely fatal yet serious disease known as Parrot Fever (typically resembling the flu or pneumonia).
Wild rock doves are pale grey with two black bars on each wing, while domestic and feral pigeons vary in colour. Females and males have few visible differences.
Peak breeding times for pigeons are spring and summer, although they mate all year round. In cities, nesting sites are usually found along the artificial cliff faces created by apartment buildings with accessible ledges or roof spaces. Pigeons tend to be monogamous, both parents raising two squabs per brood. The newly hatched squabs are pale yellow and have a light-coloured bill with a dark band. Baby squabs are tended and fed ‘pigeon milk’ through regurgitation. The pigeon milk is produced in the crops of both parents in all species of pigeons and doves. The fledging period is about 30-37 days. Pigeons in cities typically live for about four years.
Pigeons feed in the morning and afternoon, returning to their nests at night. Their repeated reuse of nests without cleaning means that feces and the remains of both unhatched eggs and dead baby birds form a hard-packed structure, likely infested with mites and lice. Pigeons may gather in flocks up to 500 birds while feeding.
Common North American predators of pigeons include owls, opossums, raccoons, eagles, gulls, crows and ravens and even domestic cats.
Feral pigeons often host intestinal helminths and range of tick, mite and lice ectoparasites that frequently invade homes from pigeon nests, on, or in the building. These parasites are capable of biting humans and transmitting the diseases that they carry. Contact with pigeon droppings can lead to the contraction of histoplasmosis, cryptococcosis, psittacosis, and bird fancier’s lung, a hypersensitivity pneumonitis. Feral pigeons also carry Newcastle disease, Aspergillosis, Pseudotuberculosis, Pigeon coccidiosis, Toxoplasmosis, Encephalitis and Salmonellosis that are contracted by humans. Although they can contract it, they do not appear to be able to transmit the West Nile Virus. Pigeons carry and spread avian influenza although they are not susceptible to H5N1, and do not transmit the virus to chickens.
Pigeon pest management and population control demands an integrated approach to pest management involving physical modifications to the property: The removal of a food source, the use of netting, wire and spikes to trap and remove pigeons from roosting sites or to render roosting sites inaccessible. Scare tactics can include the implementation of predatory bird sounds and scarecrows and the use of actual predators, i.e., peregrine falcons. Nests must be removed and the structure treated for mites and lice that will migrate in search of a new host body food source. A variety of cities have implemented a variety of pigeon population control measures like the use of reversible contraceptives, increased waste disposal controls, and designated nesting grounds that allow workers to remove and replace pigeon eggs with dummy substitutes at night while the birds sleep.
Although there is no bylaw to prevent a person from feeding wild or domesticated birds or animals, Toronto Municipal Code 629 places onus on the tenant to keep their balcony clean of potentially harmful pigeon droppings. Avicides are largely banned from use due to their non-selective nature and to avoid the risk of harming a predator population.