Appearance
Very similar to Parrot Crossbill but slighly smaller and less stocky. Male brick red in colouring, female yellowish green, juvenile greyish brown with dark streaking.
Size
Length 15–17 cm, weight 35–53 g.
Nest
High in a spruce tree. Outer layer made of dry twigs and beard lichen; middle layer decaying wood fragments and moss; lined with grass, beard lichen, hair and feathers.
Breeding
3–5 eggs laid January–March, incubated for 13 days by female, who is fed by male during this period. Fledglings remain in their nest for 16–18 days.
Distribution
Breeds and winters widely in Finland. Abundant during good years for spruce cones, bit in poor years may be almost absent, when may roam long distances to regions with more spruce cones. Finnish population estimated to range between 50,000 and 400,000 pairs.
Migration
Roams immediately after breeding completed in May–June. Autumn mass migrations often in a southwesterly direction. Roaming birds may be seen at any time of year. Wintering numbers in Finland vary greatly according to the availability of food.
Diet
Spruce seeds, also sometimes pine and larch seeds.
Calls
Metallic “plit” call given in flight, song pleasant and varied.

Crossbills have characteristic unusually shaped beaks which are sturdy with crossed tips. Crossbills are best distinguished from Parrot Crossbills by the shape of their beaks, which are more slender (especially lower mandible) and have a gently curving profile (not sloping steeply downwards in parrot-like fashion). Males have brick red plumage, females are yellowish green. Some individuals have two narrow white or pale reddish wing bars, making them resemble the related Two-barred Crossbill. But these wing bars do not become wider nearer the birds’ backs, and Crossbills do not have extensive pale markings on their tertial wing feathers as Two-barred Crossbills do.

Juvenile Crossbills are brownish grey with streaking on all parts of their plumage. Young birds in transitional plumage can be found, partly streaked with red or greenish adult colouring evident to varying degrees. Crossbills’ legs, beaks and irises are dark brown.

Crossbills and Parrot Crossbills are hard to distinguish. In some cases individuals can only be identified by measuring the ratio between the length and thickness of their beaks. Though Parrot Crossbills tend to feed more on pine cones, their feeding behaviour is not a failsafe clue to identification, since both species sometimes feed on different types of cones.

Lille Korsnæb

Taksonomi

Klasse

Orden

Familie