Red Crossbill

Loxia curvirostra

  • Version: 1.0 — Published January 1, 1996
  • Curtis S. Adkisson

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Figure 1. Distribution of the Red Crossbill in North America.

This species also breeds in Europe, Asia, and northern Africa. In North America, Red Crossbills breed occasionally outside the mapped range. During nonbreeding periods, this species disperses irregularly south of the distribution shown.

Adult male Red Crossbill head detail, Grand Forks, BC, 13 March.

Crossbills are easily distinguished from all other North American birds by their crossed elongated bill tips. These are used to pry open cones from which they extract the seed. The following is a link to this photographer's website:, Mar 14, 2013; photographer Mike Wisnicki

Adult male Red Crossbill, San Mateo Co., CA, 3 May.

Typical male plumage. Bill size and depth varies among the different types of Red Crossbills. Bill size generally correlates with the kind of seeds these types prefer; larger billed birds can open stronger cones (e.g., pine), whereas smaller billed birds prefer softer cones (e.g., fir). The following is a link to this photographer's website:, May 04, 2013; photographer Ganesh Jayaraman

Adult female Red Crossbill, San Mateo Co., CA, 3 May.

Female Red Crossbills have yellowish tones, but typically have plain grayish throats. Males often have red or yellow throats. The following is a link to this photographer's website:, May 04, 2013; photographer Ganesh Jayaraman

Red Crossbills inhabit southern taiga forests from Alaska to Newfoundland, and montane coniferous forests south to Georgia in the Appalachians, Arizona, New Mexico, northern Mexico, and the Sierra Nevada of California. Wandering birds can reach the southern states, where breeding has occurred. The species also occurs in the pine forests of Central America.

The Red Crossbill shows considerable morphological and vocal variation, and classification of the species into races has been as diverse as the many authors involved. Recent progress in the classification of this diversity is the identification of eight discrete types of Flight Calls north of the Mexican border, calls that may play a major role in maintaining reproductive isolation among the groups. These call types may represent discrete species; they are, at least, nomadic populations that are usually reproductively isolated from all other crossbills.

The nomadic movements characteristic of most of these forms are driven by the variable nature of cone production over most of North America. Individual Red Crossbills of various call types may be found far from their usual haunts, sometimes feeding on atypical food sources.

Morphological variation in bill and body size appears to be part of a suite of adaptations for different species and sizes of cones in most forms of this crossbill.

Red Crossbills breed mainly when a group finds an adequate mature cone crop of the appropriate type. In some places more than two call types may breed simultaneously, with little interbreeding, and they may breed repeatedly until food is depleted below a level of profitable foraging. Even though crossbills are often said to breed in all months of the year, a recent study of one call type shows that breeding ceases, even in the presence of a bumper crop, when autumn day length becomes shorter than about 12 hours. Then, after the annual molt, breeding can resume in late December or January at day lengths of 10.5 hours.

Recommended Citation

Adkisson, C. S. (1996). Red Crossbill (Loxia curvirostra), version 1.0. In The Birds of North America (A. F. Poole and F. B. Gill, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA.