The Eurasian Siskin (Carduelis spinus) is a small passerine bird in the finch family Fringillidae. It is also called the European Siskin, Common Siskin or just Siskin. 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. 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.
Factsheet: Eurasian Siskin Carduelis spinus