Finches

The cardueline or typical finches are smallish birds, with a strong, conical beak, well designed for extracting and eating seeds from cones and fruits. These finches also have a crop, an oesophageal pouch used to store and soften ingested seeds, and a muscular gizzard for crushing their major food of seeds. They eat buds, soft fruits, and some insects.

Most species of finches are sexually dimorphic, with male birds having relatively bright and colorful plumage, and the female being more drab, and cryptic. This coloration helps the female to blend into her surroundings while incubating her eggs, a chore that is not shared by the brightly colored male.

Species of finches occur in Europe, Asia, Africa, and the Americas. However, the greatest diversity of species occurs in Eurasia and Africa.

Cardueline finches typically occur in flocks during their non-breeding season. Many of the northern species of finches are highly irruptive in their abundance, sometimes occurring in unpredictably large populations, especially during their non-breeding season. These events of great abundance are associated with a local profusion of food, for example, at times when conifer trees are producing large quantities of cones and seeds. Crossbills, siskins, and redpolls are especially notable in this respect.

The flight of cardueline finches is strong, and often occurs in an up-and-down, undulating pattern. This flight pattern may be exaggerated during nuptial and territorial displays.

Male cardueline finches defend a territory during their breeding season, mostly by singing, often while the bird is in flight. The songs of most species are loud and melodious. The nest is cup-shaped, and may be placed in a tree, shrub, on the ground, and sometimes in a cavity in piles of rocks. The clutch size is larger in northern species and populations, and can be as few as three and as large as six. The female incubates the bluish-tinged eggs, but she is fed by the male during her seclusion. Both sexes share in the rearing of the young birds.