Lark - Description

Description

Larks are small- to medium-sized birds, 12 to 24 cm (5 to 8 inches) in length and 15 to 75 grams (0.5 to 2.6 ounces) in weight (Kikkawa 2003).

They have more elaborate calls than most birds, and often extravagant songs given in display flight (Kikkawa 2003). These melodious sounds (to human ears), combined with a willingness to expand into anthropogenic habitats — as long as these are not too intensively managed — have ensured larks a prominent place in literature and music, especially the Eurasian Skylark in northern Europe and the Crested Lark and Calandra Lark in southern Europe.

With these song flights, males defend their breeding territories and attract mates. Most species build nests on the ground, usually cups of dead grass, but in some species more complicated and partly domed. A few desert species nest very low in bushes, perhaps so circulating air can cool the nest. Larks' eggs are usually speckled, and clutch sizes range from 2 (especially in species of the driest deserts) to 6 (in species of temperate regions). Larks incubate for 11 to 16 days (Kikkawa 2003).

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 (reaching an extreme in the Thick-billed Lark) for cracking seeds open, while others have long, down-curved bills, which are especially suitable for digging (Kikkawa 2003).

Larks are the only passerines that lose all their feathers in their first moult (in all species whose first moult is known). 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 (seeds), which requires less work from the parents (Kikkawa 2003).

In many respects, including long tertial feathers, larks resemble other ground birds such as pipits. However, in larks the tarsus (the lowest leg bone, connected to the toes) 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 (Ridgway 1907).