| Photo Information |
Copyright: Gert Paassen (Gert-Paassen)
![Gold Star Critiquer/Gold Note Writer [C: 509 W: 2 N: 2049]](http://i1.treknature.com/misc/g-n-g.gif) (6428) |
| Genre: Animals |
| Medium: Color |
| Date Taken: 2007-03-08 |
| Categories: Birds |
| Exposure: f/5.6, 1/125 seconds |
| More Photo Info: [view] |
| Photo Version: Original Version |
| Date Submitted: 2008-09-09 11:53 |
| Viewed: 244 |
| Points: 24 |
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| [Note Guidelines] Photographer's Note [Dutch] |
Pigeons and doves constitute the family Columbidae within the order Columbiformes, which include some 300 species of near passerine birds. In general parlance the terms "dove" and "pigeon" are used somewhat interchangeably. In ornithological practice, there is a tendency for "dove" to be used for smaller species and "pigeon" for larger ones, but this is in no way consistently applied, and historically the common names for these birds involve a great deal of variation between the term "dove" and "pigeon." This family occurs worldwide, but the greatest variety is in the Indomalaya and Australasia ecozones. The young doves and pigeons are called "squabs."
Pigeons and doves are stout-bodied birds with short necks and short slender bills with a fleshy cere. The species commonly referred to just as the "pigeon" is the feral Rock Pigeon, common in many cities.
Doves and pigeons build relatively flimsy nests from sticks and other debris, which may be placed in trees, on ledges, or on the ground, depending on species. They lay one or two eggs, and both parents care for the young, which leave the nest after 7 to 28 days[1]. Doves feed on seeds, fruit and plants. Unlike most other birds (but see flamingo), the doves and pigeons produce "crop milk," which is secreted by a sloughing of fluid-filled cells from the lining of the crop. Both sexes produce this highly nutritious substance to feed to the young.
Feral pigeons, also called city doves, city pigeons or street pigeons, are derived from domestic pigeons that have returned to the wild. The domestic pigeon was originally bred from the wild Rock Pigeon, which naturally inhabits sea-cliffs and mountains. All three types readily interbreed. Feral pigeons find the ledges of buildings a perfect substitute for sea cliffs, and have become adapted to life and are abundant in towns and cities all over the world.
Pigeons breed when the food supply is good—for wild rock doves this might be seasonally so they usually breed once a year. In the wild they are often found in pairs in the breeding season but usually they are gregarious. In the urban environment, because of their year-round food supply, feral pigeons will breed continuously, laying eggs up to six times a year.
Feral pigeons can be seen eating grass seeds and berries in urban parks and gardens in the spring, but there are plentiful sources throughout the year from scavenging (e.g. dropped fast-food cartons). Further food is also usually available from the disposing of stale bread in parks by restaurants and supermarkets, from tourists buying and distributing birdseed, etc. Pigeons tend to congregate in large, often thick flocks when going for discarded food, and many have been observed flying skilfully around trees, buildings, telephone poles and cables, and even moving traffic just to reach it.
As a result of the continuous food supply, pigeon courtship rituals can be observed in urban parks at any time of the year. Males on the ground initially puff up feathers at the nape of the neck to increase their apparent size and thereby impress or attract attention, then they single out a female in the vicinity and approach at a rapid walk while emitting repetitive quiet notes, often bowing and turning as they approach. Initially, females invariably walk away or fly short distances, the males follow them at each stage. Persistence by the male will usually eventually cause the female to tolerate his proximity, at which point he will continue the bowing motion and very often turn full- or half-pirouettes in front of the female. Subsequent mating when observed is very brief with the male flapping his wings to maintain balance on the female. Sometimes the male and female beaks are locked together.
Nests are rudimentary as for the wild doves and pigeons. Favourite nesting areas are in damaged property. Mass nesting is common with dozens of birds sharing a building. Loose tiles and broken windows give pigeons access; they are remarkably good at spotting when new access points become available, for example after strong winds cause property damage. Nests and droppings will quickly make a mess of any nesting area. Pigeons are particularly fond of roof spaces containing water tanks, though they frequently seem to fall into the tanks and drown. Any water tank or cistern in a roof space needs to have a secure lid for this reason. The popularity of a nesting area seems little affected if pigeons die or are killed there; corpses are seen among live birds, who seem unconcerned.
On undamaged property the gutters, window air conditioners (especially empty air conditioner containment boxes), chimney pots and external ledges will be used as nesting sites. Many building owners attempt to limit roosting by using bird control spikes and netting to cover ledges and resting places on the façades of buildings. These probably have little effect on the size of pigeon populations, but can help to reduce the accumulation of droppings on and around an individual building.
Only the larger and more wary Wood Pigeon (which often shares the same territory and food supply) will build a tree nest; for some reason it prefers trees close to roads.
Feral pigeons are often considered a pest or even as vermin, owing to concerns that they spread disease and are much maligned in the media for transmitting bird flu, but it has been shown pigeons do not carry the deadly H5N1 strain. Also concerns of them damaging property, causing pollution with their excrement, and driving out other bird species. Some also consider pigeons an invasive species.
Although pest exterminators use poison, hawks or nets have been employed at ground level to control urban pigeon populations, the effect however is limited and very short term.
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 favorable nesting places for pigeons – nesting places that can easily be reached by city workers who regularly remove eggs, thereby limiting their reproductive success.
In the last few decades, people have begun to poison feral pigeons when their numbers become too large. This has proven to be fairly ineffective, however, as pigeons can breed very quickly (up to six times a year) 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.
Peregrine Falcons which are also originally cliff dwellers have also adapted to the big cities, living on the window ledges of skyscrapers and often feeding exclusively on Rock Pigeons. Some cities actively encourage this through falcon breeding programs. Falcon project on web
Larger birds of prey occasionally take advantage of this population as well. In New York City, the abundance of pigeons (and other vermin) has created such a conducive environment for predators that the Red-Tailed Hawk has begun to return in very small numbers, the most famous of which is Pale Male.
A more effective tactic to reduce the number of feral pigeons is deprivation. Cities around the world have discovered that not feeding their local birds results in a safe population decrease in only a few years. Pigeons, however, will still pick at garbage bags containing discarded food or at leftovers carelessly dropped on the ground.
Due to the huge population of feral pigeons in California, an experimental project used an animal contraceptive called "OvoControl P" in Hollywood. OvoControl P interferes with egg development, and was put in food in feeders. The venture had the support of animal rights groups.
Some groups of people are in favor of feral pigeons however. A group of New York bird watchers organized a "National Pigeon Day" that was celebrated in Central Park, with songs, prayers and speeches to honor this proud bird - not the "rats with wings" once decried by Woody Allen. Organizers with the New York Bird Club insist that our feathered neighbors are completely misunderstood. |
boreocypriensis, gracious, zulfu, techranger, Silvio2006, xTauruSx, bahadir, jaycee, eqshannon, Jamesp, haraprasan, NinaM has marked this note useful
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