The Common chaffinch is a widespread small songbird found in much of Europe, Asia, and northwestern Africa. The male is brightly colored with a blue-grey cap and rust-red underparts. The female is much duller in coloring, but both sexes have two contrasting white wing bars and white sides to the tail. The juvenile resembles the female.
The breeding range of Common chaffinches includes northwestern Africa and most of Europe and extends eastwards across temperate Asia to the Angara River and the southern end of Lake Baikal in Siberia. There are also distinctive populations on the Azores, the Canary Islands, and the Madeira Islands in the Atlantic Ocean. Common chaffinches are partial migrants; birds that breed in warmer regions are sedentary, while those breeding in the colder northern areas of their range winter further south. Chaffinches prefer wooded areas and also common in parks, gardens, orchards, agricultural areas, and hedgerows.
Common chaffinches are social birds. Outside the breeding season, they form flocks, sometimes mixed with bramblings and forage for seeds on the ground. They feed by day, often in open country but also in trees, and also occasionally make short sallies to catch insects in the air. They seldom take food directly from plants and only very rarely use their feet for handling food. Common chaffinches communicate using various types of calls and songs. The males have a strong voice and typically sing two or three different song types, and there are regional dialects also. They sing from exposed perches to attract a mate and their song may be heard from far. The common call of these birds is a sharp 'pink-pink' sound. During the flight chaffinches often produce 'yup-yup' and when alarmed they emit a 'seee' call.
Common chaffinches have a herbivorous and carnivorous (insectivorous) diet. Outside the breeding season, they mainly eat seeds and other plant material that they find on the ground. During the breeding season, their diet switches to invertebrates, especially defoliating caterpillars. The young are entirely fed with invertebrates which include caterpillars, aphids, earwigs, spiders, and grubs (the larvae of beetles).
Common chaffinches are monogamous and often form long-lasting pair-bonds. The time of breeding usually depends on the spring temperature and is earlier in southwest Europe and later in the northeast. A male attracts a female to his territory through song. Nests are built entirely by the female and are usually located in the fork of a bush or a tree several meters above the ground. The nest has a deep cup and is lined with a layer of thin roots and feathers. The female lays a clutch of 4-5 eggs, which are smooth and slightly glossy, but very variable in color. They range from pale-blueish green to light red with purple-brown blotches, spots, or steaks. The eggs are incubated for 10-16 days by the female. The chicks are altricial, hatching nearly naked with closed eyes, and are fed by both parents but mainly by the female, who broods them for around 6 days. The nestlings fledge 11-18 days after hatching and leave the nest; however, they are then still assisted with feeding by both parents for a further 3 weeks. The parents only very rarely start a second brood, but when they do so it is always in a new nest. Young chaffinches are able to breed when they are 1 year old.
Common chaffinches don't face any serious threats at present. However, populations that occur on the Macaronesian islands in the Atlantic are vulnerable to the loss of habitat. This species is also vulnerable to the use of pesticides and is trapped in some areas of its range.
According to the IUCN Red List, the total population size of the Common chaffinch is around 530,000,000-767,000,000 mature individuals. In Europe, the breeding population consists of 185,000,000-269,000,000 pairs, which equates to 371,000,000-537,000,000 mature individuals. Currently, this species is classified as Least Concern (LC) on the IUCN Red List and its numbers today are increasing.