Family Alaudidae
larks

Larks belong to the order Passeriformes, sub-order Passeri and family Alaudidae. Currently there are 17 recognized lark genera and 91 species.

Larks are small to medium-sized birds (11 to 19 cm in length) that reside in open countryside from desert to alpine tundra. They vary in color from light tan to reddish and tend to blend in well with the soil and vegetation in their chosen habitat.

Larks (particularly sky larks (Alauda arvensis)) have provided inspiration for many poets with their complex and beautiful songs. They are primarily Old World inhabitants. Horned larks (Eremophila alpestris) are the only native lark species in North America. (Dean et al., 1992; Payne, 2003; Simms, 1992; Trost, 2001)

Larks primarily live in the Old World. Fifty-seven percent of lark species are found in Africa, 19 percent in Africa and Eurasia, 16 percent in Asia, 6 percent in Eurasia and 1 percent in the New World. Horned larks (Eremophila alpestris) are the only lark species native to North America. Skylarks (Alauda arvensis) were introduced to Vancouver Island in British Columbia, Canada and can still be found there, and occasionally in Washington state. Skylarks were also introduced to Australia and New Zealand. (Campbell and Lack, 1985; Campbell et al., 1997; Dean et al., 1992; Simms, 1992)

Larks inhabit open countryside in both temperate and tropical regions. Their habitat includes: shrubland, savana, desert, tundra, grassland and farmland. Larks can be found in habitats from coastal areas at sea level to mountainous areas at an elevation of 4000 m. (Campbell and Lack, 1985; Campbell et al., 1997; Dean et al., 1992; Mead, 1985; Simms, 1992)

Larks are one of the most well defined families of passerines. However, their relationship to other passerines is unclear. They are thought to have evolved from Old World warblers (Sylviide) and flycatchers (Muscicapidae). Although they are not closely related, larks and swallows (Hirundinidae) share some primitive characteristics and are often classified next to each other. Pipits and wagtails (Motacillidae) are the most closely related family to Alaudidae.

Distinguishing characteristics: back of tarsus rounded and covered with scutes or scales, lack an ossified pessulus in the syrinx, long straight claw on hallux. (Campbell and Lack, 1985; Dean et al., 1992; Payne, 2003; Sibley and Ahlquist, 1990; Simms, 1992; Trost, 2001)

Larks are small- to medium-sized birds (11 to 19 cm long, 15 to 75 g) with fairly long legs, wings and tail. Most have long straight claws on their hind toes. The length of the claw depends on the bird’s habitat; longer claws are found on birds that live in areas with soft ground and some vegetation, shorter claws and toes are found on species that live in areas with harder ground. Their brown plumage (ranging from light tan to reddish) is often cryptic and matches the soil color. Some species have crests or tufts of feathers on their head. Sexes resemble each other, but males are usually larger and may have brighter, more distinct color and marking than females. Bill shape and length varies between species and can be a good indication of feeding ecology. Razo larks (Alauda razae) show sexual dimorphism in bill length. The male’s bill is 20 percent longer than the female’s, which suggests that males and females exploit different food sources. Larks molt once or twice per year depending on the species. Juveniles have less distinct coloring and patterns than adult birds. (Campbell and Lack, 1985; Dean et al., 1992; Mead, 1985; Simms, 1992)

Like most small birds, larks probably live on average only two to five years. The longest living known individuals are an 8 year, 5 month old skylark (Alauda arvensis) and a 7 year 11 month old horned lark (Eremophila alpestris). Average annual mortality for skylarks is 33 percent. (Campbell and Lack, 1985; Gill, 1995; Trost, 2001)

Most larks are solitary, although some will flock in agricultural fields to feed and others flock after the breeding season prior to migrating. Some larks are sedentary, others are nomadic, moving in response to rainfall and food availability and others (particularly Northern Temperate species) are long-distance migrants. Larks are usually found in low densities, but are found closer together in high quality habitat.

Larks run rather than hop along the ground and rarely perch on shrubs and trees, except occasionally to sing. Many clean by dusting, although some bath in water. Depending on the species, they molt once or twice a year. Larks that live in desert areas will stand in the shade of grass tussocks during the hottest parts of the day.

Larks are territorial and defend their territories through song and flight displays. Some species will also raise their feather crests during a display. (Campbell and Lack, 1985; Campbell et al., 1997; Dean et al., 1992; Gill, 1995; Mead, 1985; Simms, 1992)

Lark flight, feeding, threat and display calls are quite simple, however, their territorial song is very elaborate. In addition to communicating through song, larks will raise the crest of feathers in their head during agonistic and courtship displays.

Larks can locate buried insects by ear while foraging. (Mead, 1985; Simms, 1992)

Larks are omnivorous and forage on the ground. They eat many species of insects in addition to seeds, grasses, leaves, buds, fruits and flowers (especially during the winter when insects are less available). Some species will also eat snails (Gastropoda), which they break open on rocks. Larks' insect prey are diverse and include: Ephemeroptera (mayflies), Diptera (true flies), Hemiptera (true bugs), Coleoptera (beetles), Collembola (springtails), Orthoptera (grasshoppers), Lepidoptera (adult and larval moths) and Isoptera (termites). Skylarks (Alauda arvensis) in England feed on at least 47 species of insect. Desert species acquire water from their food and dew.

The shape of a Lark’s bill is adapted to its diet and feeding technique. For example, hoopoe larks (Alaemon) have long decurved bills that are used for digging for insect larvae, while calandra larks (Melanocorypha) have strong, stout bills that are used for eating seeds. Some can also locate buried insects by ear. (Campbell and Lack, 1985; Dean et al., 1992; Mead, 1985; Simms, 1992)

Adult larks have numerous avian predators: falcons (Falconiformes), owls (Strigiformes) and shrikes (Laniidae). Adults, chicks and eggs are also taken by mammals. Common mammalian predators include: weasels (Mustelinae), skunks (Mephitinae), squirrels (Sciruidae), raccoons (Procyon lotor) and house cats (Felis domesticus). Additional nest predators include: voles and mice (Rodentia), shrews (Sorex), crows (Corvidae) and western meadowlarks (Sturnella neglecta). Up to 90 percent of lark nests may be lost to predators.

In response to nest predators, incubating females will flush silently when the predator is far from the nest; if the predator is close to the nest she will feign injury to draw it away. Young larks leave the nest early, this is thought to decrease predation and/or decrease the chance that an entire clutch is lost simultaneously.

Larks’ cryptic plumage allows them to blend in with the ground and makes it more difficult for predators to spot them; they will often avoid using patches of ground that do not match their coloration. Foraging in flocks is also thought to be an adaptation to reduce predation. (Beason, 1995; Campbell and Lack, 1985; Dean et al., 1992; Mead, 1985; Simms, 1992)

As insectivores, larks affect insect populations throughout their range.

Because they occasionally feed in flocks in agricultural fields, larks are recognized as agricultural pests. In the United States they will damage crops of beets, broccoli, carrots, lettuce, peas, spinach, tomatoes, alfalfa, grain, sugar beets, cantaloupe and watermelon. (Clark and Hygnstrom, 1994)

Larks can be important agents in the control of agricultural pests. For example, an adult skylark (Alauda arvensis) was found with 48 weevils (Sitona lineatus) in its stomach. This particular species of weevil is a pest on peas. (Simms, 1992)

The IUCN lists two species of larks as critically endangered, two species as endangered and four as vulnerable. North American species are protected under the Migratory Bird Treaty Act. No larks are listed by CITES or ESA.

Declining numbers are the result of habitat loss, degradation and fragmentation, poisoning from chemicals used on crops and introduced species (especially those that are nest predators). Some species may stand to benefit from the clearing of forested areas to create pastures and arable land. ("UNEP-WCMC Species Database: CITES-Listed Species", 2003; Campbell et al., 1997; IUCN, 2002; Mead, 1985; Simms, 1992; Threatened and Endangered Species System, 2003; U.S. Fish and Wildlife Service, date unknown)