The Eurasian siskin (Spinus spinus) is a small passerine bird in the finch family Fringillidae. It is also called the European siskin, common siskin or just siskin. Other (archaic) names include black-headed goldfinch, barley bird and aberdevine. 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 underparts 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 centimeters (4.3–4.9 in) in length with a wingspan that ranges from 20–23 centimeters (7.9–9.1 in). It weighs between 10–18 grams (0.35–0.63 oz). They are very active and restless birds. They are also very social, forming small cohesive flocks especially in autumn and winter. They are fairly trusting of humans, it is possible to observe them from a short distance. During the breeding season, however, they are much more timid, solitary and difficult to observe. For this reason there is a German legend which says that siskins guard a magic stone in their nests that makes them invisible. It is one of the few species which has been described as exhibiting "allofeeding"' behavior, this is where subordinates (of the same sex) regurgitate food for the dominant members of the group, which creates a strong cohesion in the flocks and implies a hierarchical structure within the group. In Pakistan Siskin is considered as a vagrant. Few recent records from Borit Lake, upper Hunza.