crossbill, bird of the genus Loxia, in the finch family. Its bill, crossed at the tips, is specialized for pulling apart pine cones and picking out the seeds. Crossbills are found in the evergreen forests of the Northern Hemisphere, as far south as NW Africa and Guatemala. Two species occur in the United States. The red crossbill ( L. curvirostra ) is found in Europe and in N and central Asia as well as in North America. Males have orange to dull red plumage, with black wings. The white-winged crossbill ( L. leucoptera ) occurs in northern Russia and in North America; the male of this species is rosy red and both sexes are marked with white wing bars. Females of both species are olive-gray and yellow; they lay three to four pale green, brown-spotted eggs, in well-formed nests built in trees. Crossbills are not considered migratory, but they shift their breeding grounds erratically, probably in response to the availability of pine cones. Sometimes they suddenly appear in large numbers in areas where they were formerly rarely seen. They are classified in the phylum Chordata, subphylum Vertebrata, class Aves, order Passeriformes, family Fringillidae.