Horned larks are widespread songbirds found across the northern hemisphere. They are mainly brown-grey above and pale below, with a striking black and yellow face pattern. Except for the central feathers, the tail is mostly black, contrasting with the paler body; this contrast is especially noticeable when the bird is in flight. In summer males have black "horns", which give these birds their American name. North America has a number of races distinguished by the face pattern and back color of males, especially in summer. The southern European mountain race is greyer above, and the yellow of the face pattern is replaced with white.
Horned larks breed across much of North America from the high Arctic south to the Isthmus of Tehuantepec, northernmost Europe, and Asia and in the mountains of south-east Europe. There is also an isolated population on a plateau in Colombia. Horned larks are mainly resident in the south of their range, but northern populations are migratory, moving further south in winter. These are birds of open ground. They breed in the tundra and alpine habitats, and on seashore flats. In North America, where there are no other larks to compete with, they can also be found on farmland, on prairies, in deserts, on golf courses and airports.
Horned larks are diurnal and gregarious; they form large flocks often with other species but during the breeding season they are often seen in pairs or small groups. Horned larks forage on the ground walking or running around in search of insects and seeds. They communicate with the help of high-pitched, lisping or tinkling sounds. They also sing in flight and their song consists of a few chips followed by a warbling, ascending trill.
Horned larks are serially monogamous and pairs stay together for one season. During the breeding season, they become very territorial. Males defend territories from other males and females will occasionally chase away intruding females. Horned larks usually breed in spring and summer. Courting is composed of the male singing to the female while flying above her in circles. He then will fold his wings in and dive towards the female, opening his wings and landing just before hitting the ground. The nest site is selected in the early spring by only the female and is either a natural depression in the bare ground or she digs a cavity using her bill and feet. She will spend 2-4 days preparing the site before building her nest. She weaves fines grasses, cornstalks, small roots, and other plant material and lines it with down, fur, feathers, and occasionally lint. In the south, females can produce 2-3 broods a year while in the north, 1 brood a year is more common. A clutch usually consists of 2-5 gray eggs with brown spots. Incubation takes 10-12 days until hatching and then the nestling period will take 8-10 days. During the nestling period, helpless chicks are fed and defended by both parents. They are able to fly at 16-18 days old and reach the adult size at about one month.
Horned larks are threatened by the loss of habitat due to agricultural pesticides, urbanization, and human encroachment. They also suffer from collisions with wind turbines. In the open areas of western North America, Horned larks are among the bird species most often killed by wind turbines.
According to the IUCN Red List, the total Horned lark population size is more than 140,000,000 individuals. The European population consists of 2,140,000-6,510,000 pairs, which equates to 4,280,000-13,000,000 mature individuals. National population sizes have been estimated at around 100-10,000 breeding pairs, around 50-1,000 individuals on migration and 50-1,000 wintering individuals in China and less than 1,000 individuals on migration and less than 1,000 wintering individuals in Japan. Overall, currently, this species is classified as Least Concern (LC) on the IUCN Red List but its numbers today are decreasing.