Lark
Larks are passerine birds of the family Alaudidae. Larks have a cosmopolitan distribution with the largest number of species occurring in Africa. Only a single species, the horned lark, occurs in North America, and only Horsfield's bush lark occurs in Australia. Habitats vary widely, but many species live in dry regions. When the word "lark" is used without specification, it often refers to the Eurasian skylark .
Taxonomy and systematics
The family Alaudidae was introduced in 1825 by the Irish zoologist Nicholas Aylward Vigors as a subfamily Alaudina of the finch family Fringillidae. Larks are a well-defined family, partly because of the shape of their. They have multiple scutes on the hind side of their tarsi, rather than the single plate found in most songbirds. They also lack a pessulus, the bony central structure in the syrinx of songbirds. They were long placed at or near the beginning of the songbirds or oscines, just after the suboscines and before the swallows, for example in the American Ornithologists' Union's first check-list. Some authorities, such as the British Ornithologists' Union and the Handbook of the Birds of the World, adhere to that placement. However, many other classifications follow the Sibley-Ahlquist taxonomy in placing the larks in a large oscine subgroup Passerida. For instance, the American Ornithologists' Union places larks just after the crows, shrikes, and vireos. At a finer level of detail, some now place the larks at the beginning of a superfamily Sylvioidea with the swallows, various "Old World warbler" and "babbler" groups, and others. Molecular phylogenetic studies have shown that within the Sylvioidea the larks form a sister clade to the family Panuridae which contains a single species, the bearded reedling. The phylogeny of larks was reviewed in 2013, leading to the recognition of the arrangement below.Extant genera
The family Alaudidae contains 98 extant species which are divided into 21 genera: For more detail, see list of lark species.Extinct genera
Description
Like many ground birds, most lark species have long hind claws, which are thought to provide stability while standing. Most have streaked brown plumage, some boldly marked with black or white. Their dull appearance camouflages them on the ground, especially when on the nest. They feed on insects and seeds; though adults of most species eat seeds primarily, all species feed their young insects for at least the first week after hatching. Many species dig with their bills to uncover food. Some larks have heavy bills for cracking seeds open, while others have long, down-curved bills, which are especially suitable for digging.
Larks are the only passerines that lose all their feathers in their first moult. This may result from the poor quality of the chicks' feathers, which in turn may result from the benefits to the parents of switching the young to a lower-quality diet, which requires less work from the parents.
In many respects, including long tertial feathers, larks resemble other ground birds such as pipits. However, in larks the tarsus has only one set of scales on the rear surface, which is rounded. Pipits and all other songbirds have two plates of scales on the rear surface, which meet at a protruding rear edge.