Product Code Database
Feral pigeons are birds derived from domestic pigeon populations of the rock dove ( Columba livia), descendants that have escaped and are living independently from (and often unwanted by) humans, having gone "feral". They are sometimes given the scientific names " Columba livia domestica" or " C. l. urbana", but neither of these subspecies names is accepted by any of the ornithological authorities like the IOC World Bird List or BirdLife International. They are also called city doves, city pigeons, or street pigeons,Nagy, Kelsi, and Johnson, Phillip David. Trash animals: how we live with natures filthy, feral, invasive, and unwanted species. Minneapolis (Minn.), University of Minnesota Press, 2013. and (locally, in Britain) skemmies ( skemmy). Wild rock doves, domestic pigeons, and feral pigeons are all the same species and will readily interbreed. Many domestic birds have been lost, escaped or been release dove over the years, and these gave rise to populations of feral pigeons.
Feral pigeons inhabit man-made structures such as buildings as a Exaptation for cliffs and other Outcrop. Their domestic ancestry predisposed them to living near humans, and they subsequently became adapted to urban life, being abundant in towns and cities throughout much of the world. They are often described as a public nuisance, being a potential reservoir of disease and cause of property damage, through their habits and numbers. Many authorities and citizens consider them to be pests and an invasive species, often disparagingly referred to as "rats with wings". Actions are taken in many municipalities to lower their numbers or completely eradicate them.
The blue-barred pattern which the original wild rock dove displays is generally less common in more urban areas. Pigeons feathers have two types of melanin (pigment) – eumelanin and pheomelanin. A study of melanin in the feathers of both wild rock and domestic pigeons, of different colouration types and known genetic background, measured the concentration, distribution and proportions of eumelanin and pheomelanin and found that gene mutations affecting the distribution, amounts and proportions of pigments accounted for the greater variation of colouration in domesticated birds than in their wild relations. Eumelanin generally causes grey or black colours, while pheomelanin results in a reddish-brown colour. Other shades of brown may be produced through different combinations and concentrations of the two colours. Urban pigeons tend to have darker plumage than those in more rural areas. Darker birds may be better able to store in their feathers due to their higher concentrations of melanin, which may help mitigate the negative effects of the metals, the concentrations of which are typically higher in urban areas.
Compared to their wild relatives, feral pigeons are unafraid of humans due to their long history of domestication, and are extremely trusting and tolerant of people.
The avoidance of Inbreeding is ordinarily regarded as adaptive since it decreases the likelihood of inbreeding depression in progeny that can be caused by the expression of deleterious recessive . However in feral pigeons it was found that despite detectable inbreeding depression, pairwise relatedness between mates was significantly greater than it was between nonmates. This suggests that mating with close kin provides inclusive fitness benefits that outweigh the costs of inbreeding depression.
Studies of feral pigeons in a semi-rural part of Kansas found that their diet includes the following: 92% maize, 3.2% , 3.7% cherry, along with small amounts of knotweed, elm, poison ivy and barley. They have been observed to eat insects and spiders. Pigeons tend to congregate in large, dense flocks when feeding on discarded food. In cities they typically resort to scavenging human garbage, as unprocessed grain may be impossible to find. Pigeon groups typically consist of producers, which locate and obtain food, and scroungers, which feed on food obtained by the producers. Generally, groups of pigeons contain a greater proportion of scroungers than producers. Feral pigeons can be seen eating grass and berries in parks and gardens in the spring, but plentiful sources exist throughout the year from scavenging (e.g., food remnants left inside of dropped fast food cartons, in the form of popcorn, cake, peanuts, bread and Zante currant) Food is also procured from . Bird feeding, often tourists or residents who feed pigeons, do so for reasons such as empathy, fun, tradition and as a means for social interaction.
Pigeons often suffer injuries to their legs and feet due to contact with foreign objects in their environment, particularly hair or string, which gets wrapped around their legs and cuts off the blood supply, in some cases resulting in autoamputation.
Chlamydophila psittaci is endemic among pigeons and causes psittacosis in humans. It is generally transmitted from handling pigeons or their droppings (more commonly the latter). Psittacosis is a serious disease but rarely fatal (less than 1%).
Pigeons are also important vectors for various species of the bacteria Salmonella, which causes diseases such as salmonellosis and paratyphoid fever. There were single case incidences for transmission of Salmonella enterica.
Pigeons are not a major concern in the spread of West Nile virus: though they can contract it, they apparently do not transmit it to humans.
Avian paramyxovirus (PMV) is carried by pigeons and is a serious affliction in birds.
Pigeons can compete with native birds for nest sites, which could become a conservation issue for .
The scarcity of the wild rock dove is largely due to interbreeding with feral birds.
Contact with pigeon droppings poses a minor risk of contracting histoplasmosis, cryptococcosis and psittacosis, Pigeon faeces has been implicated as a "contributing factor" a cryptococcus infection leading to the death of a child.
Feral pigeon faeces cause substantial economic losses from property damage, often considered to be from their corrosive droppings damaging stone edifices and metal structures.
In the U.S., the Migratory Bird Treaty Act of 1918, which protects native birds, does not apply to feral pigeons, or , because they are introduced species. It is usually legal to kill feral pigeons in the United States; methods such as poisons may be regulated, however. Pigeons are labeled an invasive species in North America by the USDA.
In India, pigeons are protected under Section 428 and Section 429 of the Indian Penal Code. Wild pigeons are further protected under the Wildlife Protection Act, 1972.
Other predators of the pigeon have been recorded, including Eurasian sparrowhawks ( Accipiter nisus), Corvus ( Corvus spp.), and large ( Larus spp.).Archived at Ghostarchive and the
target="_blank" rel="nofollow"> Wayback Machine: Larger birds of prey occasionally take advantage of these pigeons as well. Eurasian goshawk have been known to specialize on feral pigeons even outside of urban settings. In New York City, the abundance of feral pigeons (and other small animals) has created such a conducive environment for predators that the red-tailed hawk has begun to return in very small numbers, including the notable Pale Male. Pale Male – Introduction – Red-tailed Hawk in New York City | Nature. PBS (May 2004). Retrieved 22 August 2012.
Other common predators of feral pigeons in North America are , , great horned owls, and eastern screech owls. The birds that prey on pigeons in North America can range in size from to .
In London, the population of great white pelicans at St. James's Park has also been recorded killing and consuming pigeons even when alternative food sources are available. In cities in Western Europe, European herring gulls may occasionally hunt and consume feral pigeons in addition to other birds and small mammals.
Despite their importance in the diet of urban predatory birds, feral pigeons are known to transmit several diseases to their consumers, as they may be reservoirs of several avian diseases, often . Raptors may contract West Nile Virus through consumption of infected bird species, such as Corvus, , and pigeons. Trichomoniasis, frounce, or canker is a significant disease in raptors both captive and wild-living. Symptoms include plaques in and around the oropharynx, and lesions may be found in the Bird lung, , sinuses, ear canal and kidneys. The may progress into severe Necrosis, at least of the upper digestive tract. Trich has been found to be resistant to several drug treatments, and it is thought that "preventive treatments" that use insufficient dosages may be one of the causes. These diseases may prove to be fatal to the raptors; Columbid Herpesvirus-1 has a near 100% mortality rate in raptors.
Long-term reduction of feral pigeon populations can be achieved by restricting food supply, which in turn involves legislation and litter (garbage) control. Some cities have deliberately established favourable nesting places for pigeons, nesting places that can easily be reached by city workers who regularly remove eggs, thereby limiting their reproductive success. In addition, pigeon populations may be reduced by bird control systems that successfully reduce nesting sites.
The active ingredient, nicarbazin, interferes with the viability of eggs by binding the ZP-3 sperm receptor site in the egg. This unique contraceptive action is non-hormonal and fully reversible.
Registered by the EPA as a pesticide (EPA Reg. No. 80224-1), "OvoControl P", brand of nicarbazin, is increasingly used in urban areas and industrial sites to control pigeon populations. Declared safe and humane, the new technology is environmentally benign and does not represent a secondary toxicity hazard to raptors or scavengers.
Avian contraception has the support of a range of animal welfare groups including the Humane Society of the United States, the American Society for the Prevention of Cruelty to Animals and People for the Ethical Treatment of Animals. Avian contraceptives are also perceived by some civilians as an acceptable method for population control, over other methods such as prohibition to feeding or extermination.
The use of poisons has been proven to be fairly ineffective, however, as pigeons can breed very quickly, and their numbers are determined by how much food is available; that is, they breed more often when more food is provided to them. When pigeons are poisoned, surviving birds do not leave the area. On the contrary, they are left with more food per bird than before. This attracts pigeons from outside areas as well as encouraging more breeding, and populations are re-established quickly. An additional problem with poisoning is that it also kills pigeon predators. Due to this, in cities with peregrine falcon programs it is typically illegal to poison pigeons.
A statue of a pigeon by artist Paul Sloan was installed at the Rundle Mall, Adelaide, South Australia, adding to their collection of art installations, including statues of pigs. Sloan intended to "elevate the humble pigeon" with his work titled Pigeon. The mirrored stainless steel statue cost . While the installation has been talked up by City of Adelaide Lord Mayor Sandy Verschoor, some locals have responded negatively.
|
|
