This interesting finch has a distinctive offset overlapping bill that provides good leverage for separating seeds from the scales of the cones of pines and spruce trees. The specialization on conifer cone seeds as the primary food source is the reason that Red crossbills are almost exclusively found in evergreen forests. Interestingly, the crossing of the upper bill over the lower may occur on either side, and at hatching the bills of nestlings are normal. The bills of juveniles grow and the upper bill crosses the lower after a month or more, when they become able to efficiently extract seeds from the scales of conifer cones.
Males show dull reddish to orange feathers on the head, breast and back, with brown wings. Females are dull brown with olive or yellowish highlights. Immatures show more streaking that adults. The size is about the same as a cowbird, stocky with a large head. They often perch high on the upper limbs of conifers and are commonly found in small flocks. Crossbills aren’t migratory, being well adapted to survive cold conditions, though they may travel widely within their range as large groups search for good food supplies.
Foods are primarily conifer seeds with some buds of deciduous trees and grasses, as well as some insects and berries. Nestlings are fed regurgitated seeds. Nests are open cups placed at any height in conifers and built of a variety of vegetation and hair and feathers. The female is fed by the male as she tends the nest and both parents cooperate to feed nestlings. Pairs are monogamous and stay together throughout the year.
The song and calls show a variety of rather unmusical short chips and raspy slurs, repeated several times.
Red crossbills are widespread in evergreen forests around the world, in the U.S. and Canada and across the boreal forests of Europe and Asia. In the U.S. crossbills are found year round in evergreen forests in New Mexico and the Rockies as well as the Sierras and Cascades of the western states. The IUCN (International Union for Conservation of Nature) reports that worldwide, populations of Red crossbills are stable and not threatened. The Audubon Society predicts a range shift northward in the U.S. and Canada as the climate continue to warm over time.