The Red Crossbill: An Unusual Beak

By Dave Hanks

This beak is not deformed. Nature intended it to be thus. It is an adaptation for the opening of cones. While useful for that purpose, it does make the bird into a specialist and whether the beak crosses to the right or to the left runs about 50-50. Crossbills must have coniferous forests in order to survive and because conifer cones may last on the tree up to 20 years, there is no need to migrate out of an area of good cone production. Therefore their movements are irregular and controlled by cone availability.

There are two species of crossbills in North America: the Red Crossbill and the White-Winged Crossbill. The red variety is hard to “spot”, but is very abundant in the Cassia and Twin Falls mountain areas. The more glamorous White-Winged one is an inhabitant of boreal (northern) forests.

These interesting birds may not come to seed feeders, but water can be a major attraction. They are very gregarious and will come in to drink in large groups. The all-red, mature male is pictured. Immature birds are boldly streaked brown. The females are yellowish-olive and may show patches of red. The species is 6 ¼” long, with a large head, and a short, notched tail.

Different strains of the species are each adapted to a specific tree type (i.e. Lodgepole Pine, Ponderosa Pine, Douglas Fir, etc). Other species such as finches, chickadees, and siskin benefit from the nuts not consumed after a cone is opened. Crossbills are also quite vocal and will call while in flight. Each individual’s calls may vary somewhat from other individuals, giving that bird a character of its own. It gives a rapid series of harsh “jip” notes, started with several two-note phrases and followed by a warbled trill.

The female lays three eggs, but only two individuals usually fledge and there is about a 12% survival rate of the young into the second year. It is enough, however, to maintain the bird’s population numbers.

The crossbills of our south hills have the largest beaks of their kind. They are an isolated population and researchers are thinking of denoting them as a separate species. When camping, the presence of crossbills gives one a true flavor of the mountain experience. It is a truly unique bird!