Monday, February 28, 2011

Eurasian Siskin

Eurasian Siskin (Cardelius spinus).

Sent by Lamberto, a postcrosser from Italy.

This is from Wikipedia : The Eurasian Siskin (Carduelis spinus) is a small passerine bird in the finch family Fringillidae. It is very common throughout Europe and Asia. It is found in forested areas, both coniferous and mixed woodland where it feeds on seeds of all kinds, especially of alder and conifers. It can be distinguished from other similar finches by the color of the plumage. The upper parts are greyish green and the under parts grey-streaked white. Its wings are black with a conspicuous yellow wing bar, and the tail is black with yellow sides. The male has a mainly yellow face and breast, with a neat black cap. Female and young birds have a greyish green head and no cap. It is a trusting, sociable and active bird. The song of this bird is a pleasant mix of twitters and trills. For these reasons it is often raised in captivity.

These birds have an unusual migration pattern as every few years in winter they migrate southwards in large numbers. The reasons for this behavior are not known but may be related to climatic factors and above all the availability of food. In this way overwintering populations can thrive where food is abundant.

This small finch is an acrobatic feeder, often hanging upside-down like a tit. It will visit garden bird feeding stations.

The Siskin is a small, short-tailed bird, 11–12.5 centimetres (4.3–4.9 in) in length with a wingspan that ranges from 20–23 centimetres (7.9–9.1 in).[2][4][5] It weighs between 10–18 grams (0.35–0.63 oz).[2][4][6]

The bird's appearance presents a sexual dimorphism. The male has a greyish green back; yellow rump; the sides of the tail are yellow and the end is black; the wings are black with a distinctive yellow wing stripe; its breast is yellowish becoming whiter and striped towards the cloaca; it has a black bib (or chin patch) and on its head it has two yellow auriculas and a black cap. The amount of black on the bid is very variable between males and the size of the bib has been related to dominance within a flock.

The plumage of the female is more olive-colored than the male. The cap and the auriculas are greenish with a white bib and a rump that is a slightly striped whitish yellow.

The young have a similar coloration to the females, with drab colors and a more subdued plumage.

The shape of the Siskin's beak is determined by its feeding habits. It is strong although it is also slender in order to pick up the seeds on which they feed. The legs and feet are dark brown and the eyes are black.

The Siskin is easy to recognize, but in some instances it can be confused with other finches such as the Citril Finch, the Greenfinch or the European Serin.

It has a rapid and bounding flight pattern that is similar to other finches.

This bird has two calls, both powerful but conflicting, one is descending and the other is ascending, their onomatopoeic sounds can be represented as "tilu" and "tluih". On occasions they also issue a harsh rattling chirrup.

The song is similar to the other finches, a smooth and rapid twitter and trill with a long duration and which is occasionally interrupted by a stronger of shorter syllable. Siskins sing throughout the year and often in groups.

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