City pigeon

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City pigeon ( Columba livia f. Domestica )

The city pigeon or street pigeon is a bird from the family of pigeons (Columbidae). It probably comes mainly from feral domestic and carrier pigeons , which were bred from the rock pigeon ( Columba livia ), but the origin of the street pigeons is not completely clear. Feral and semi-wild city pigeons are already reported in ancient writings . Today they are spread all over the world. Since city pigeons emerged from a former domestic animal form, are rewilded and are now living as wild animals again, one speaks of a pariah form in zoological terminology .

features

Black and white color morphs are relatively rare in city pigeons

The city pigeon has a body length of 31 to 34 cm. It is smaller than the wood pigeon and has a shorter tail. The plumage is very variable. Their shape often resembles the rock pigeon , some of the numerous plumage variations look very similar to the rock pigeon. Otherwise there are also white-gray patterned, uniformly dark gray or dark brown, red-gray or dark piebald color variants. The iris is red or brown.

Regional peculiarities have also developed. The black “dock pigeon” is known from Birmingham ; it is black and coarser than other city pigeons. The street or city pigeons in Seville , Spain, on the other hand, are predominantly white and may breed in tree hollows.

Voice, courtship behavior and communication

Males in impressive pose

The cooing uttered by both sexes is very variable and sounds something like "gúrr" or "guu-ru-gu." The male mates with a deep, rumbling "gang-grrru-guruú-u", which is sometimes lined up evenly. In the first part of this motif it bows, in the last part it straightens up again. At the nest, a long drawn-out call is uttered in repetition, something like "quiet". The warning call is a short, monosyllabic stressed "hu". Other sounds are also used to communicate with one another. Loud or quiet clacking noises are generated with the goiter. The springs rub against each other as they tremble, creating a rustling sound. During the courtship flight, the wings are clapped quickly several times, which also serves to mark the territory. The boys beg with bright beeping sounds while they are being fed.

distribution and habitat

Distribution of the street pigeon.
Dark red: natural range of the rock pigeon.
Light red: introduced populations

The habitat of the city pigeons are cities all over the world. City pigeons also occur outside of cities, especially in areas that have been changed by humans. As a descendant of the rock pigeon, whose habitat is rocky coasts and caves, the city pigeon is normally not able to breed on trees (it is very rare, as an exception, to breed on street trees), it is dependent on houses, walls and bridges etc. as a substitute for rocks .

nutrition

Like their wild relatives and all related pigeon species, city pigeons are primarily grain and seed-eaters who feed mainly on grain and legume seeds, but can opportunistically use a variety of food sources depending on the availability. Diet by insects, snails and worms is occasionally used as a supplement, but is quantitatively meaningless. Urban pigeon populations pursue two different strategies for food supply, depending on the local food supply. Pigeons that breed in the city either fly into the rural area, where they feed on grain and other crops in the fields, or they look for food directly in the city. Forage search at warehouses, granaries, ports and other reloading points combines features of both strategies. The breeding period and the breeding success correlate to a high degree with the seasonal food supply. In addition, pigeons ingest earth or stones, which serve as gastrolites , but probably also improve the mineral supply. In cities, city pigeons are often specifically fed by animal lovers in addition to the food they are looking for, which also includes waste. Viewed worldwide, only a few urban pigeon populations are dependent on this food source, but it can be locally decisive, especially when there are very high densities in city centers.

City pigeons usually band together in flocks while foraging. Such swarms of food are not random aggregations, but rather the birds interact socially with each other, for example dominance hierarchies in access to food have been demonstrated. The animals of a food swarm do not correspond to those of a certain breeding colony, they can join different swarms. City pigeons also prefer contact with conspecifics when resting, although resting flocks are independent in their composition. Food swarms can fly several kilometers to known, rich food sources together, whereby individual individuals can “train” the swarm to previously unknown sources.

Reproduction and Life Expectancy

Females can mate as early as five months of age. The first brood is possible as early as six months. Most of the city pigeons breed in the second calendar year. Most of the time, the partners live in monogamy for life . The breeding pairs keep throughout the year in the breeding area on. The males occupy a nesting area that can contain several nesting sites and is usually kept for life. It lures the female to the nesting place on ledges, inside caves, holes in rock walls or similar places on buildings, sometimes also in closed rooms that can be reached through windows and the like.

The nest is built by both sexes, with the male entering the nesting material, and usually consists of a thin layer of twigs, roots, stalks, feathers, paper and plastic scraps, and more rarely of wire or the like. Often the eggs are laid on the bare floor of the hatchery without a support. Older breeding grounds are covered with a thick layer of pigeon droppings . The breeding season lasts around 17 to 18 days on average. The main breeding season in Central Europe is usually from March to August or into October, but breeding in autumn and winter is not uncommon. These are common in the UK and are also found in Norway and Finland .

Normally there are two to four broods per year, up to six complete broods can occur. In the UK, only three to six are completed from seven to nine scrims. If the clutch is lost, a new clutch can be created in 10 to 14 days. The clutch almost always consists of two eggs, sometimes one, very rarely three. The eggs are spindle-shaped, oval, white and slightly shiny. They are 34 to 42 millimeters long and 26 to 31 millimeters wide. They are laid 48 hours apart and incubated by both partners for 17 to 18 days, starting with the first egg .

After hatching, the nestlings are initially often hoed and fed with crop milk by both partners . As they get older, their parents leave them alone in the nest during the day and feed them only about four times a day. Meanwhile, the parents go to the second nest and begin a new breeding sequence. The young leave the nest when they are 23 to 25 days old. With 30 to 35 days they are fully airworthy and independent. However, you stay close to him and only leave the family group much later, when your own partner has been chosen.

In city centers, boy mortality is up to 90% in the first year of life. The average life expectancy is 2 to 3 years. Under optimal conditions, city pigeons can also reach an age of more than 10 years.

Animal rights activists keep saying that full pigeons breed less and raise fewer young than hungry pigeons. Increased feeding would make the pigeon population smaller, not larger. However, Birte Stock and Haag-Wackernagel found in a very elaborate study to take into account the sudden loss of a very important main feed source in the port of Basel, that hungry pigeons breed less than well-fed pigeons and, as a result, fewer young birds fly out. In the investigation, there was a decrease in the number of breeding pigeons or pairs from 193 to 145, the number of eggs laid from 926 to 503, the number of hatched pigeons from 340 to 195, and the number of fledglings from 240 to 113, i.e. by more than half.

Enemies

In large parts of the distribution area, the street pigeon is the main prey of the peregrine falcon , eagle owl , martens and cats. The female sparrowhawk also occasionally kills pigeons.

City pigeon and human

City pigeons in a pedestrian zone
Pigeon defense strips with needles rounded at the tip as approach protection on a railway signal in Giessen station

In Germany, city pigeons are considered pests within the meaning of the Animal Welfare Act when they occur in high population densities and can cause various problems.

Conversely, people can become a danger to city pigeons through environmentally harmful behavior.

Damage to buildings

A city pigeon leaves 4–12 kg of faeces per year, which in large populations leads to massive pollution wherever pigeons stay for a long time. Since pigeons can temporarily store large amounts of food in the crop, faeces can accumulate, especially in buildings that are popular as resting places. Quantities of 0.5 to 1.5 grams per process are estimated, which results in around 11 to 26 grams per day (24 hour period). The pigeon droppings represent a visual and hygienic impairment. Damage to the building structure by pigeon droppings is also reported. The freshly deposited faeces only have a very weakly acidic pH value of around 6.5, but after some time (approx. 100 hours) it drops to more acidic values ​​of approx. 4.5. In addition to the direct damage to limestone by the organic acids, there are reports of damage from salt efflorescence in crevices and the increased growth of puke-decomposing microorganisms and fungi. Especially in historical buildings, which are often made of sensitive natural stone and which have richly structured facades with protrusions, niches and cavities, city pigeons, along with seagulls, are the most questionable species in this regard. The droppings of city pigeons are, probably because of the often poor quality food, even more harmful than that of other pigeons.

Transmission of pathogens

Pigeons can suffer from bacterial diseases (salmonellosis, ornithosis, tuberculosis, cocci and coli infections), mycoses (aspergillosis, thrush) or viral diseases (pigeon pox, pigeon herpes, paramyxovirus infection, Newcastle disease, circovirus infection, leukosis, adenovirus infection). The endoparasites of pigeons include coccidiosis, trichomonadosis , hexamitiasis, toxoplasmosis and various types of worms. Most of the diseases mentioned are not specific to pigeons, but occur in other birds such as B. songbirds, birds of prey and poultry. Infectious diseases in humans caused by pigeons (zoonoses) obviously occur only rarely. Mostly people with a weakened immune system are affected. The source of infection is often the inhalation of dried infected pigeon droppings.

An important viral disease in pigeons, like many other birds, are Paramyxoviridae , which cause the so-called Newcastle disease (also: atypical avian influenza), which they can transmit to poultry flocks in human care. Normally there is no danger to humans.

Ornithosis , transmitted by the bacterium Chlamydophila psittaci (parrot bird psittacosis is the same pathogen) can be a problem . According to the statistics of the Federal Health Office, the reportable ornithosis afflicts around 300 people each year, of which only 8% can be traced back to pigeons. These are mainly pigeon fanciers who have close contact with their birds. With a prevalence of a few percent, the pathogen can be detected in urban pigeon populations, for example in the city of Basel. Transmission to humans only appears likely if there is close contact with the birds. But there are also other pathogenic chlamydia in city pigeons.

Salmonellosis is one of the most common infections in humans. However, this is the poisoning caused by Salmonella in food. In pigeons, however, the type Salmonella typhimurium occurs predominantly in the Copenhagen variant , and this type has so far not been scientifically proven in people suffering from Salmonella.

The poultry tuberculosis is notifiable. Pigeons can get infected with fowl tuberculosis caused by Mycobacterium avium , which mainly affects chicken birds, through contaminated water or feed. The pigeon's dry, dusty droppings are the most common source of infection for humans. Infection with avian tuberculosis is less severe than with human tuberculosis or bovine tuberculosis, but it can be dangerous for severely immunocompromised people.

Pigeons are hosts of influenza viruses , including avian influenza H7N9 and H5N1 (but not avian influenza H5N8 , avian influenza). The infection rate of tested pigeons was just over one percent. In experimental infections with the viruses, their mortality was very low. The small amounts of virus excreted in the faeces are considered to be of no health significance. City pigeons and domestic pigeons are therefore considered to be insignificant in the case of bird flu infections, which are also contagious to humans.

Some of the diseases mentioned are not only transmitted through direct contact, but also through the animal's faeces. Health significance are mainly caused by the fungus Cryptococcus neoformans caused cryptococcosis . In general, fresh manure is classified as more contagious than already dried up and sun-bleached manure. B. coccidia and trichomonads are thereby killed. When removing pigeon droppings, high concentrations of microorganisms can be found in the air. The pigeon keeper's lung, now generally referred to as the bird keeper's lung, is triggered by an allergic reaction to the frequent inhalation of dust from bird droppings and feathers.

City pigeons are regularly infested with large numbers of ectoparasites . In Central Europe these include pigeon bug Cimex columbarius , pigeon flea Ceratopsyllus columbae , red poultry mite Dermanyssus gallinae , and pigeon tick Argas reflexus . Stings of the latter two types are particularly significant for humans. Both are species that do not live as permanent ectoparasites on their pigeon host, but in the area of ​​colonies and nests. They can penetrate human dwellings when nesting in attics etc. and suck blood here, often after the pigeons themselves have been killed or driven away in a fight. While mortality in pigeons is high (nestling losses of around a quarter), humans usually only experience harmless, itchy local sting reactions (reddening and wheals).

Pigeon defense

Pigeon house in Luxembourg City, attempt to control the population
Remains of a city pigeon beaten by a bird of prey

In many cities, great effort is for Bird Control operated low to the number of pigeons and keep the building dove free. The measures can be manifold: Suspending buildings or parts of buildings with nets, approach barriers such as needles ( pigeon guard rails ), wires (partly with current flowing through them) or adhesive gels. These local problems are usually caused by frequent feeding in the immediate vicinity that attracts the pigeons.

Modern city districts often have significantly fewer problems with city pigeons because there are usually fewer breeding opportunities there, for example in the roof area and on cornices. Cities with extensive historical structures, on the other hand, show significantly more opportunities for street pigeons to breed. A large-scale reduction in the available breeding grounds (especially in the area of ​​private buildings) is difficult in reality, but in many individual cases it is sensible and important.

Feeding ban or pigeon houses - attempts to solve the pigeon problem

The pigeon defense is only effective locally. It does not solve the city-wide problems of city pigeons. Therefore, attempts were also made to reduce the pigeon population by shooting and hunting with falconers . The shooting of pigeons and the chasing of animals by trained falcons does not solve the problem either. The pigeon population removed is far too small to be efficient, the lower pigeon density leads to increased breeding success and the deficit is replenished very quickly. The shooting is also not in accordance with animal welfare, and hunting is usually prohibited in inner-city areas. The laying out of poisonous bait is not justifiable under animal welfare law, and the uncontrollable release of poisons into the environment leads to the death of countless birds of prey and scavengers, but also of ducks, etc. Food dragees with integrated contraceptive pills are problematic because such agents are only effective if they are taken regularly and consistently and this is practically impossible to implement in wild animals. The release of hormones into the environment can also cause problems in the raptor population.

Animal rights activists often promise the city-wide regulation of street pigeons through dovecotes in which the new pigeon population is looked after and the eggs of the breeding pigeons are partially replaced by dummies . This method is mainly used in Germany and Holland. There are currently over 168 pigeon houses in Germany. A success control of such pigeon houses - by counting before and after - has not yet been carried out. Pigeon houses are mainly adopted by pairs of young pigeons without a breeding place, which have not been able to breed, because of the high level of loyalty to the location of breeding pigeon pairs. Any breeding sites that become free are quickly taken over by non-breeding pairs of young pigeons. It is therefore scientifically undisputed that pigeon houses cannot regulate the city-wide population of street pigeons in practice. The constant removal of eggs in the pigeon houses also leads to high brood stress. Pairs of pigeons also leave the pigeon houses again when they notice that they are not breeding success; it is therefore necessary to leave pigeon eggs regularly, which endangers regulation even inside the pigeon house. The generally good feed supply for the pigeons in the pigeon houses also leads to a significantly higher number of eggs being laid. Richard Köhler stated in a study for the city of Bochum in 2008: "A success of the [dovecote] method due to the mechanism of action specified by the operators is - despite intuitively plausible and initially convincing arguments - due to reliable ecological and population-biological expertise."

Only reducing the amount of food available (feeding ban) is proven to be effective in restricting the population of city pigeons while at the same time improving the state of health, as Daniel Haag-Wackernagel noted in his numerous researches. It is necessary to always inform the population through the various media about the need for a feeding ban or about the harmfulness of feeding, including z. B. Posters or notice boards in places with high feeding are important.

Picture gallery

  • egg

  • Nest with two eggs

  • Hatched chick and an intact egg

  • Chick, one day old

  • Chick, five days old

  • Chick, around ten days old

  • Chick, 16 days old

  • Young bird, 22 days old

  • portrait

See also

literature

in alphabetical order by authors / editors

  • H.-G. Bauer, E. Bezzel , W. Fiedler : The compendium of birds in Central Europe. Everything about biology, endangerment and protection . Vol. 1: Nonpasseriformes - non-sparrow birds. 2. completely revised Ed. Aula, Wiebelsheim, 2005, ISBN 3-89104-647-2 .
  • Daniel Haag : A contribution to the ecology of the city pigeon . Dissertation at the University of Basel Phil. Nat. Faculty, Medical Biology. Basel 1984, DNB  455844356 .
  • Werner Lüthgen: pigeon diseases . 3rd, revised edition. Oertel + Spörer, Reutlingen 2006, ISBN 3-88627-619-8
  • Martin Mach: Between love and disgust: the third-party funded project “Focus Dove” . In: Monument Preservation Information , Issue 171, 2019, pp. 70–75.
  • L. Svensson, PJ Grant, K. Mullarney, D. Zetterström: The new cosmos bird guide. All kinds of Europe, North Africa and the Middle East . Franckh-Kosmos, Stuttgart 1999, ISBN 3-440-07720-9

Web links

Commons : Stadttaube  - album with pictures, videos and audio files
Wiktionary: Stadttaube  - explanations of meanings, word origins, synonyms, translations

Individual evidence

  1. ↑ a b Joachim Schütte: Handbook of the pigeon races. The pigeon breeds in the world . 1994, ISBN 978-3-9801504-4-6 ( Stadttauben and Urs N. Glutz von Blotzheim (Hrsg.): Handbuch der Vögel Mitteleuropas. Ed. 14 volumes, Aula-Vlg, Wiesbaden 1985ff. (2nd ed.)) .
  2. ↑ Edmund Zurth: pigeons . Factual reports. Fates and riddles in their essence. Schürmann & Klagges, Bochum 1949, DNB  455844356 .
  3. ↑ Mention of the pigeon Morphe from Birmingham in NATUR & Land , 91st year, issue 1 / 2-2005, there p. 11
  4. ^ Richard F. Johnston & Marián Janiga: Feral Pigeons. Oxford University Press, New York and Oxford 1995. ISBN 0-19-508409-8 , therein Chap. 11, Diet.
  5. ^ Richard F. Johnston & Marián Janiga: Feral Pigeons. Oxford University Press, New York and Oxford 1995. ISBN 0-19-508409-8 , therein Chap. 15, Social behavior.
  6. ↑ Stefan Bosch, Peter Havelka: Please do not feed ... How humans and urban pigeons get along better. In: NABU.de. NABU - Naturschutzbund Deutschland e. V., accessed on March 14, 2013 .
  7. ^ Daniel Haag : A contribution to the ecology of the city pigeon . Dissertation, Phil. Nat. Faculty of the University of Basel. Medical Biology Publishing House, Basel 1984, p. 260 .
  8. ^ Daniel Haag: Life expectancy and age structure of the street pigeon . In: Ala, Swiss Society for Ornithology and Bird Protection (ed.): The ornithological observer . tape 87 , issue 2.Sempach June 1990, p. 147–151 ( PDF; 452.67 KB [accessed March 14, 2013]).
  9. ^ Daniel Haag-Wackernagel: Basler Taubenaktion. Retrieved March 14, 2013 .
  10. ↑ Birte Stock and Daniel Haag : Food Shortage affects reproduction fo Feral Pigeons . Columba livia at rearing of nestlings. In: Ibis (magazine) . 2016.
  11. ↑ Derek Ratcliffe: The Peregrine Falcon. 2nd Edition. Poyser, London, 1993. ISBN 0-85661-060-7 , pp. 116ff
  12. ^ Judgment of the VGH Hessen , file number 8 A 396/10 of September 1, 2011.
  13. ↑ Jan Dönges: Why city pigeons often lose their toes. In: Spektrum.de . November 14, 2019, accessed November 18, 2019 .
  14. ↑ a b Dirk HR Spennemann & Maggie J. Watson (2017): Dietary habits of urban pigeons (Columba livia) and implications of excreta pH - a review. EJE European Journal of Ecology 3 (1): 27-41. doi: 10.1515 / eje-2017-0004
  15. ↑ a b Miguel Gómez-Heras, David Benavente, Mónica Álvarez de Burgo, Rafael Fort (2004): Soluble salt minerals from pigeon droppings as potential contributors to the decay of stone-based Cultural Heritage. European Journal of Mineralogy 16: 505-509.
  16. ↑ M. Bassi & D. Chiatante (1976): The role of pigeons excrement in the stone deterioration. International Biodeterioration 12: 73-79.
  17. ↑ Daniel Haag-Wackernagel: The pigeon problem and ways to its solution. In: DVG German Veterinary Medical Society, Section Animal Welfare Law. 17th International Symposium "Current Findings on Animal Welfare", Nürtingen 12./13. March 2012, p. 280
  18. ^ Adam Abouzeid, David Channon, Phil Sever: Bird Damage to Historic Buildings . Cathedral Communications Limited 2013.
  19. ↑ Dirk HR Spennemann, Melissa Pike, Maggie J. Watson (2017): Effects of acid pigeon excreta on building conservation. International Journal of Building Pathology and Adaptation 35 (1): 2-15. doi: 10.1108 / IJBPA-09-2016-0023
  20. ^ Nancy J. Thomas, D. Bruce Hunter, Carter T. Atkinson (editors): Infectious Diseases of Wild Birds. Blackwell Publishing, Ames (Iowa) 2007, ISBN 978-0-8138-2812-1 .
  21. ↑ World Health Organization (WHO), Regional Office for Europe 2008: Public health significance of urban pests (PDF; 3.5 MB) .
  22. ^ D. Haag-Wackernagel, H. Moch: Health hazards posed by feral pigeons. In: Journal of Infection 2004; 48 (4), pp. 307-313.
  23. ↑ Ila violin enemy, Daisy Vanrompay, Daniel Haag-Wackernagel (2012): Prevalence of Chlamydia psittaci in the feral pigeon population of Basel, Switzerland. Journal of Medical Microbiology 61: 261-265. doi: 10.1099 / jmm.0.034025-0
  24. ↑ Konrad Sachse, Simone Kuehlewind, Anke Ruettger, Evelyn Schubert, Gernot Rohde (2012): More than classical Chlamydia psittaci in urban pigeons. Veterinary Microbiology 157: 476-480. doi: 10.1016 / j.vetmic.2012.01.002
  25. ↑ Celia Abolnik (2014): A current review of avian influenza in pigeons and doves (Columbidae). Veterinary Microbiology 170 (3-4): 181-196. doi: 10.1016 / j.vetmic.2014.02.042
  26. ^ Avian flu risk: license for pigeons. Spigel Online, February 17, 2006
  27. ↑ Daniel Haag-Wackernagel (2010): Health hazard from street pigeons. Science Practice, Biology in School 59 (7): 26-30.
  28. ↑ Health hazards caused by pigeon droppings civil engineering professional association, bgbau.de February of 2003.
  29. ^ Daniel Haag-Wackernagel (2008): Health hazards caused by the street pigeon Columba livia: Parasites. Official Veterinary Service and Food Control 15 (3): 174-188.
  30. ↑ cf. Daniel Haag-Wackernagel : Basel pigeon campaign. Research Group Integrative Biology, University of Basel and «Please do not feed pigeons!» Start of the Basel pigeon campaign 2016. Communication from the University of Basel, April 14, 2016.