The Eurasian siskin (Spinus spinus) is a small passerine bird from the finch family, commonly known as the European siskin. It is found across Europe and Eurosiberia, predominantly in coniferous and mixed woodlands, where it feeds on seeds, particularly from alder and conifers.
This bird can be identified by its greyish-green upper parts, grey-streaked white underparts, black wings with a prominent yellow wing bar, and a black tail with yellow sides. Males have bright yellow faces and breasts, along with a black cap, while females and young birds are more olive-colored and lack the cap.
The siskin exhibits an unusual migration pattern, migrating south in large numbers every few years, likely due to climatic factors and food availability. It is an acrobatic feeder, often hanging upside down while foraging at garden bird feeders.
Measuring 11 to 12.5 centimeters in length with a wingspan of 20 to 23 centimeters, the siskin weighs between 12 and 18 grams. Although it is easily recognizable, it can be confused with similar finches like the citril finch and European greenfinch.
Eurasian siskins are social and active, forming small flocks, especially in winter. They are also known for their “allofeeding” behavior, where subordinate birds regurgitate food for dominant members, indicating a hierarchical social structure. Primarily granivorous, they seek seeds of deciduous trees and often forage in cultivated areas alongside other finches.
