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The two-barred crossbill (Loxia leucoptera), known as the white-winged crossbill in North America, is a small passerine bird in the finch family Fringillidae. It has two subspecies, white-winged crossbill Loxia leucoptera leucoptera in North America, and two-barred crossbill Loxia leucoptera bifasciata in NE Europe and N Asia.
This bird breeds in the coniferous forests of Alaska, Canada, northernmost USA and across Asia extending into northeast Europe. It nests in conifers, laying 3–5 eggs.
This crossbill is mainly resident, but will irregularly irrupt south if its food source fails. The American race seems to wander more frequently than the Eurasian subspecies. This species will form flocks outside the breeding season, often mixed with other crossbills. It is a rare visitor to western Europe, usually arriving with an irruption of red crossbills.
The crossbills are characterised by the mandibles crossing at their tips, which gives the group its English name. They are specialist feeders on conifer cones, and the unusual bill shape is an adaptation to assist the extraction of the seeds from the cone. Two-barred crossbill has a strong preference for larch (Larix), in Eurasia using Siberian larch (Larix sibirica) and Dahurian larch (L. gmelinii), and in North America Tamarack larch (L. laricina). It will also take rowan Sorbus berries, and in North America, also eastern hemlock (Tsuga canadensis) and [wWhite spruce]] (Picea glauca) cones. source: wikipedia