The yellowhammer is a small songbird in the bunting family that is native to Eurasia. The male yellowhammer has a bright yellow head, streaked brown back, chestnut rump, and yellow underparts. The female is less brightly colored, and more streaked on the crown, breast, and flanks. Outside of the breeding season both the male and the female are less strongly marked and the dark fringes on new feathers obscure the yellow plumage. The juvenile is much duller and less yellow than the adults and often has a paler rump.
Yellowhammers breed across the Palearctic, although they are absent from high mountains, Arctic regions, the western Netherlands, most of Iberia and Greece, and low-lying regions of other countries adjoining the Mediterranean Sea. They breed in Russia east to Irkutsk, and in most of Ukraine. The Asian range extends into northwest Turkey, the Caucasus, and northern Kazakhstan. Most populations remain in the breeding range year-round, but the eastern birds are partially migratory and winter further south. Yellowhammers are birds of dry, open country, preferably with a range of vegetation types and some trees from which to sing. They frequent forest and woodland clearings, shrublands, grasslands, farmland, and plantations.
Yellowhammers are active during the day and are often seen perched on top of bushes singing their rhythm like 'a little bit of bread and no cheese' song. They feed on the ground, usually in flocks outside the breeding season. When not breeding, yellowhammers forage in flocks that can occasionally number hundreds of birds, and often contain other buntings and finches. To communicate with each other yellowhammers use various calls. Their main vocalizations include a 'zit' contact call, a 'see' alarm, and a trilled 'tirrr' given in flight. The males of this species are famous for their beautiful songs. They learn their songs from their fathers, and each male has an individual repertoire of song variants within its regional dialect; females tend to mate with males that share their dialect and prefer those with the largest repertoires.
Yellowhammers are herbivores (granivores) and their diet consists mainly of seeds. Grasses are also important, particularly cereals, and grain makes up a significant part of the food consumed in autumn and winter. In the breeding season yellowhammers add invertebrates to their diet, particularly as food for their growing chicks. They take springtails, grasshoppers, flies, beetles, caterpillars, earthworms, spiders, and snails.
Yellowhammers are monogamous and form pairs. Breeding normally starts in early May, but often in April in the south of the range. The males establish territories along hedges or woodland fringes and sing from a tree or bush, often continuing well into July or August. The male also displays to the female by raising his wings and running towards her. After the pair was formed the female starts building the nest. The nest is usually located on or near the ground, and is typically well hidden in tussocks, against a bank, or low in a bush. It is constructed from nearby plant material, such as leaves, dry grass, and stalks, and is lined with fine grasses and sometimes animal hair. The female then lays a clutch is usually 3 to 5 whitish eggs, typically patterned with a network of fine, dark lines. She incubates the eggs for 12-14 days to hatching and broods the altricial (helpless), downy chicks until they fledge 11-13 days later. Both adults feed their young in the nest and two or three broods are raised each year. Young birds start to breed when aged one year.
Yellowhammers are not considered endangered at present, however, changes to agricultural practices have led to population declines in western Europe. These birds also suffer indirectly from the use of insecticides and herbicides, which reduce the abundance of insects and spiders they prey on.
According to the IUCN Red List, the total population size of the yellowhammer is 40,000,000-69,999,999 mature individuals. In Europe, the breeding population consists of 12,800,000-19,900,000 pairs, which equates to 25,500,000-39,700,000 mature individuals. Currently, this species is classified as Least Concern (LC) on the IUCN Red List but its numbers today are decreasing.