Swallow

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For other uses, see Swallow (disambiguation).
Swallows and Martins
Welcome Swallow
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Passeriformes
Suborder: Passeri
Family: Hirundinidae
Vigors, 1825
Genera

Many, see text.

The swallows and martins are a group of passerine birds in the family Hirundinidae which are characterised by their adaptation to aerial feeding. Swallow is also used in Europe as a synonym for the Barn Swallow.

This family comprises two subfamilies: Pseudochelidoninae (the river martins of the genus Pseudochelidon) and Hirundininae (all other swallows and martins). Within the Hirundiniae, the name "martin" tends to be used for the squarer-tailed species, and the name "swallow" for the more fork-tailed species; however, there is no scientific distinction between these two groups.[1]

It is believed that this family originated in Africa as hole-nesters; Africa still has the greatest diversity of species.[1]

Contents

[edit] Description

Swallows have adapted to hunting insects on the wing by developing a slender streamlined body, and long pointed wings, which allows great manoeuvrability and endurance.

Like the unrelated swifts and nightjars, which hunt in a similar way, they have short bills, but strong jaws and a wide gape. Their body length ranges from about 10–24 cm (3.9–9.4 in) and their weight from about 10–60 g (0.4–2.1 oz). The wings are long, pointed, and have nine primary feathers. The tail has 12 feathers and may be deeply forked, somewhat indented, or square-ended. A long tail increases manoeuvrability, and may also function as a sexual adornment, since the tail is frequently longer in males. Female Barn Swallows will select mates on the basis of tail length.

The legs are short, and their feet are designed for perching rather than walking, as the front toes are partially joined at the base, causing the bird to display a waddling gait.

The most common hirundine plumage is glossy dark blue or green above and plain or streaked underparts, often white or rufous. Species which burrow or live in dry or mountainous areas are often unglossed brown above (eg Sand Martin and Crag Martin). The sexes show no, or only limited, sexual dimorphism, with longer outer tail feathers in the adult male probably being the commonest distinction where one exists.

The chicks hatch naked and with closed eyes. Fledged juveniles usually appear as duller versions of the adult.

[edit] Habitat

Mud nests made by swallows.
Mud nests made by swallows.
Hungry Barn Swallow chicks in nest
Hungry Barn Swallow chicks in nest

Swallows typically build mud nests close to overhead shelter in locations that are protected from both the weather and predators. Many cave and cliff dwelling species of swallow nest in large colonies. In historical times, the introduction of man-made stone structures such as barns and bridges, together with forest clearance, has led to an abundance of colony sites around the globe, significantly increasing the breeding ranges of some species. Birds living in large colonies typically have to contend with both ectoparasites and conspecific nest parasitism. Old males benefit most from coloniality, since they are able to maintain their own nests and benefit from frequent extra-pair copulations.

[edit] Behaviour

Barn Swallow chicks waiting to be fed
Barn Swallow chicks waiting to be fed

Swallows are excellent fliers, and use these skills to attract a mate and to defend territory. In general, the males select a nest site, and then attract a female using song and flight, and guard their territory. The size of the territory varies depending on the species of swallow; in colonial-nesting species it tends to be small, but it may be much larger for solitary nesters. The air speed of an unladen European swallow is estimated to be roughly 24 miles per hour (39 km/h).[2]

Pairs of mated swallows are monogamous,[3] and pairs of non-migratory species often stay near their breeding area all year, though the nest site is defended most vigorously during the breeding season. Migratory species often return to the same breeding area each year, and may select same nest site if they were previously successful in that location. First-year breeders generally select a nesting site close to where they were born and raised.[4]

Most species hunt over open country or near water.

Swallows are able to produce many different calls or songs, which are used to express excitement, to communicate with others of the same species, during courtship, or as an alarm when a predator is in the area. Begging calls are used by the young when soliciting food from their parents. The typical song of swallows is a simple, sometimes musical twittering.

[edit] Species in taxonomic order

Subfamily Pseudochelidoninae (river martins)
Subfamily Hirundininae (all other swallows & martins)

[edit] References

  1. ^ a b Turner, Angela; Rose, Chris (1989). Swallows and martins: an identification guide and handbook. Houghton-Mifflin. ISBN 0-395-51174-7. 
  2. ^ style.org > Estimating the Airspeed Velocity of an Unladen Swallow
  3. ^ Hirundinidae
  4. ^ Swallows (Hirundinidae): Information and Much More from Answers.com

[edit] External links

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