The Turtle-Dove

Ornithology (from Greek: ?????, ???????, ornis, ornithos, "bird"; and ?????, logos, "knowledge") is a branch of zoology that concerns the study of birds. Several aspects of ornithology differ from related disciplines, due partly to the high visibility and the aesthetic appeal of birds. Most marked among these is the extent of studies undertaken by amateurs working within the parameters of strict scientific methodology.

The science of ornithology has a long history and studies on birds have helped develop several key concepts in evolution, behaviour and ecology such as the definition of species, the process of speciation, instinct, learning, ecological niches, guilds, island biogeography, phylogeography and conservation. While early ornithology was principally concerned with descriptions and distributions of species, ornithologists today seek answers to very specific questions, often using birds as models to test hypotheses or predictions based on theories. Most modern biological theories apply across taxonomic groups and the number of professional scientists who identify themselves as "ornithologists" has therefore declined. A wide range of tools and techniques are used in ornithology and innovations are constantly made.

The homing pigeon is a variety of domesticated Rock Pigeon (Columba livia domestica) that has been selectively bred to be able to find its way home over extremely long distances. The wild rock pigeon has an innate homing ability, meaning that it will generally return to its own nest and its own mate. This made it relatively easy to breed from the birds that repeatedly found their way home over long distances. Flights as long as 1800 kilometers have been recorded by birds in competition pigeon racing. Their average flying speed over moderate distances is around 48 km/h (30 mph), but speeds of up to 95 km/h (59 mph) have been observed.

Homing pigeons are called carrier pigeons when they are used to carry messages. This is possible where a message is written on thin light paper (such as cigarette paper) and rolled into a small tube attached to the bird's leg; this is called pigeon post. Pigeons can only go back to one "mentally marked" point that they have identified as their home. So "pigeon mail" can only work when the sender is actually holding the receiver's pigeons. White homing pigeons are used in Release Dove ceremonies at weddings, funerals, and some sporting events.

The Turtle Dove (Streptopelia turtur), also known as European Turtle Dove is a member of the bird family Columbidae, which includes the doves and pigeons.

It is a migratory species with a southern Palearctic range, including Turkey and north Africa, though it is rare in northern Scandinavia and Russia; it winters in southern Africa.

According to the State of Europe's Common Birds 2007 report, the Turtle Dove population in Europe has fallen by 62% in recent times. This is partly because changed farming practices mean that the weed seeds and shoots on which it feeds, especially Fumitory, are scarcer, and partly due to shooting of birds during migration in Mediterranean countries.

Smaller and slighter in build than other doves, the Turtle Dove may be recognised by its browner colour, and the black and white striped patch on the side of its neck, but it is its tail that catches the eye when it flies from the observer; it is wedge shaped, with a dark centre and white borders and tips. When viewed from below this pattern, owing to the white under tail coverts obscuring the dark bases, is a blackish chevron on a white ground. This is noticeable when the bird stoops to drink, raising its spread tail. It has also been known to be territorially aggressive.

Category: Image - :2006 1031turturduva0224.JPG|thumb|left|A young turtle dove photographed in Nynäshamn, Sweden.

The mature bird has the head, neck, flanks, and rump blue grey, and the wings cinnamon, mottled with black. The breast is vinaceous, the abdomen and under tail coverts are white. The bill is black, the legs and eye rims are red. The black and white patch on the side of the neck is absent in the browner and duller juvenile bird, which also has the legs brown.

The Turtle Dove, one of the latest migrants, rarely appears in Northern Europe before the end of April, returning south again in September, but is often seen in April.

It is a bird of open rather than dense woodlands, and frequently feeds on the ground. It will occasionally nest in large gardens, but is usually extremely timid, probably due to the heavy hunting pressure it faces on migration. The flight is often described as arrowy, but is not remarkably swift.

The nuptial flight, high and circling, is rather like that of the Wood Pigeon, but the undulations are less decided; it is accompanied by the whipcrack of the downward flicked wings. The arrival in spring is heralded by its purring song, a rather deep, vibrating ?turrr, turrr?, from which the bird's name is derived. Despite the identical spelling, the "turtle" of the name, derived from Latin turtur, has no connection with the marine reptile, "turtle" in that case coming originally from Late Latin tortuca.

A few other doves in the same genus are also called turtle doves:

* the Asian Oriental Turtle Dove S. orientalis and Spotted Turtle Dove S. chinensis.

* the African Dusky Turtle Dove S. lugens and Laughing Dove S. senegalensis.

S. senegalensis and S. chinensis have been introduced into Australia.

A New World dove of similar appearance and behaviour to that of the Turtle Dove is the Mourning Dove.

Pigeons and doves constitute the bird family Columbidae within the order Columbiformes, which include some 300 species of near passerines. 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 terms "dove" and "pigeon." This family occurs worldwide, but the greatest variety is in the Indomalaya and Australasia ecozones. Young doves and pigeons are called "squabs."

Pigeons and doves are stout-bodied birds with short necks, and have short slender bills with a fleshy cere. The species commonly referred to just as "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. 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.

Crop milk, also known as 'pigeons milk or pigeon milk''', is a secretion from the lining of the crop of pigeons and doves with which the parents feed their young by regurgitation. Similar crop milk is also produced by flamingos.