Behavior And Reproduction
Despite their generally lackluster appearance, larks are energetic and charismatic birds. They are particularly known for their long, beautiful songs, which can last from a few minutes to an hour. Several of the species, especially the Mongolian lark, the crested lark, and the melodious or Lakatoo lark, are capable of imitating dozens of different birds and even human whistling. Most singing comes from male larks during mating season, when they use aerial song-displays to attract mates and defend their territories. Typically the males will ascend from a perch vertically before descending while singing, either gliding back down or closing his wings to plummet in a dive that he stops only by opening his wings at the last moment. Some species of lark, including the Dupont's lark, make rattling sounds with their flight feathers during their ascent, while others, namely the black lark, clap their wings over their back during their song-displays. The flapped lark uses wing sounds exclusively, and some species sing only from perches at the tops of trees, bushes, and rocks instead of during aerial song-displays.
Desert-dwelling species such as the sparrow-lark never settle in one place, their nomadic movements depending on food supply and rainfall. Both migratory and nomadic lark species tend to gather in flocks, and sometimes form male- or female-only flocks in the winter. Many of the seed-eating larks join together in large flocks.
With the exception of mating season, when some species occasionally sing at night, larks are active during the daytime (diurnal) and sleep at night in shallow depressions they carve into the ground with their claws. Like many birds, they bathe in dust or sand rather than water, although they have been seen deliberately letting rain soak their feathers. Larks prefer to scratch their heads on pointed objects such as branches and rocks, rather than using their claws. Strong fliers, they can often be identified by their undulating flight pattern during which they periodically close their wings. However, many species of these birds can walk and run so quickly that they often need not fly. Larks that live in hot, dry climates perch on raised stones and bushes to stay off the hot ground, taking shelter during the heat of the day in lizard burrows or the shade of rocks or plants. Parents shade their nestlings by standing over them with spread wings.
Rainfall, even very erratic precipitation, will trigger breeding behavior in nomadic species of lark. Otherwise, the regular breeding season occurs from March through July or whenever the rainy season begins. As a family, larks are monogamous (muh-NAH-guh-mus) for at least one breeding season and may raise one to three broods together. Males attract a mate on the ground by hopping and prancing around an interested female in an upright posture; presenting an upright tail; drooping, slightly spreading, and sometimes quivering the wings; and raising the feathers on top of the head. Throughout this display, males sing fragments of their characteristic songs, and sometimes offer small pieces of food prior to mounting the female.
The majority of larks build their grass-lined nests in shallow, cup-shaped indentations that they scratch into the ground. If this is impossible for some reason, many larks will surround a small area with pebbles or other small items to delineate the space. Several species build a dome over their nests using plant materials and supported by close-by vegetation. Usually females build their nests alone, but the male of such species as the calandra lark and the Oriental skylark typically assists. Males of other species, including the chestnut-backed sparrow-lark, present ritual gifts of such useful items as spider webs, pebbles, and other nesting material.
Lark eggs are generally light yellow or cream-colored, with an even covering of spots. Females lay one egg per day in the early morning, and in years of abundant rainfall and other beneficial factors will lay a clutch of two to five eggs. Larks that live in harsher climates often have smaller clutches. Once the female has laid all her eggs, she begins to incubate, sit on to warm, them. In some species, including the sparrow-lark, the male might help incubate the clutch as well. However, both sexes of all lark species feed and care for the chicks. While still unable to fly, the young eat food provided by the parents. The male will care for a second brood alone, if it occurs.