#363 White-winged Crossbill (Loxia leucoptera)

03 March 2021

Usually further north than Montreal but seen occasionally in winter in the Arboretum. Breeds in the coniferous forests of Alaska, Canada, the northernmost United States and across the Palearctic 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 Eurosiberian subspecies. This species will form flocks outside the breeding season, often mixed with other crossbills.

The crossbills are characterized 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. The two-barred crossbill has a strong preference for larch (Larix), in Eurosiberia 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 white spruce (Picea glauca) cones.

Geographical distribution of White-winged crossbill
Adult males tend to be red or pinkish in colour, and females green or yellow, but there is much variation. The two-barred is easier to identify than other crossbills, especially in North America, where only the red crossbill and this species occur, but some care is still needed.

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