Larks are a familiar feature of the bird communities of most open areas within
The Old World. They are particularly varied and plentiful in the arid areas of Africa. Many species have evolved elaborate songs which are often given in flight.
Although many species of larks are associated with very arid deserts or semidesert areas, this does not mean that they necessarily need hot climates. In the arctic tundra sand high on mountain ranges (as well as through much of North America) the Horned lark breeds while a survey found the skylark of Britain to be that country’s most widespread breeding bird. Most species are brown birds although some have dark markings and white patches on their plumage–in some cases only readily visible when the birds are in flight.
For the most part, their plumage serves to conceal the birds when they are on the ground and, par-secularly, when they are incubating. Most species have fairly strong bills although one, the Thick-billed lark, has a monstrous beak similar in size to that of a hawfinch, and others, like the Bifasciated lark, have rather long and down-curved bills. Many species have been seen to dig in the ground when feeding—either searching for insects or, more often, for seeds.
In common with many other pre-dominantly ground-dwelling birds larks generally have fairly long legs with longhand claws: these give them additional stability on the ground. Although some species fly at the slightest sign of danger many prefer to escape by walking or running. These species are often masters at using the contours of the ground and any vegetation for concealment during their retreat. Many species have no need for trees or bushes within their area but others regularly perch on posts, bushes, or trees. These are often birds of open scrubland and include the varied genus of bush-larks.
Although most species are predominantly seed-eating all take some invertebrate food at times. For example, when they are feeding young birds animal protein seems to be essential. In natural habitats, the availability of seeds may be severely limited—for instance in desert conditions —and so birds may only be found singly or in pairs. However, where there has been a particularly productive set of seeds, for instance immediately after the rains in a normally arid area or where crops are being cultivated, flocks of dozens or even hundreds of larks may be found. These will normally be of a single species, but flocks of mixed species are not uncommon.
Many species that are highly territorial and defend their territories and advertise their mates, by singing in flight. Many songs are very pleasing to men. Examples the skylark, woodlark, Bifacial, and Calendar larks. The latter regular: 7sings from the ground and has often bee7kept as a songbird in the MediterraneaT.region. Recognition and warning calls are also pleasing and more elaborate than thar_those found in some other groups.
In many areas, the breeding season of larks is strongly related to rainy seasons breeding starts in time for the young to be the nest as the weed seed stocks reach their peak. In such circumstances, only a single brood may be raised but temperate species often raise two and even three Almost all species nest on the ground, sometimes in the open but usually at least partly concealed in some vegetation. A few species. Mostly from the hottest desert areas, build nests just off the ground in hushes where the circulation of the air may cool the nes’.slightly.
Some incubating birds have been observed spending long periods on the nests standing up and shading the eggs from the sun at its height. Clutch sizes are often lowing very hot and dry areas—Fischer’s finch-lark generally has a clutch of two and nests in equatorial East Africa. Other temperate species regularly lay four, five, or even six eggs—for example, the skylark and Crested larks breeding in Europe. Several desert-dwelling species have been described as building a buttress of stones below the lower edge of their nest which is generally built on a slope. This has been postulated as a method of allowing the nest to drain quickly in the event of a flash flood.
The young always receive some insect food in their first days but many species revert 1:0 a vegetable diet well before the chicks move away from the nest, still flight-less, within two weeks of hatching. It is thought that this immediate change to vegetable food may lead to the fledglings having rather poor-quality feathers and certainly, all lark species so far studied undergo a com-plate post-juvenile molt. Most other passer-Ines only molt the body plumage at this stage and retain the wing and tail feathers grown in the nest for most of a year.
Modern agricultural techniques within areas where crops are being maximized are probably affecting populations adversely, income cases through direct poisoning due to misuse of chemicals, and in others, because weed seeds are gradually being eliminated from cultivated areas and so depriving the birds of their winter food. There is, however, certainly no reason to fear the loss of the familiar song of the skylark and for years to come it will remind people of Shelley’s immortal words:
- Hail to thee, blithe Spirit!
- A bird that never were
That from Heaven or near it, Pourest thy full heart
In profuse strains of unpremeditated art. (From Ode to a Skylark, 1819.)
Although they probably originated in natural grassland in Africa, the wagtails and pipits are now one of the most widespread bird families in the world. They must have benefited considerably from forest clearance carried out by man and are now commonly found in the farmland of many types. A few species, notably the White wagtail, are strongly associated with man, being common around habitations, parks, and golf courses. Several species live in close harmony with domestic livestock, using these animals as “beaters” to flush insect prey from the grassland they inhabit.
All members of this family are essentially birds of open country. Two genera, the long claws, and the Golden pipit are still largely confined to savanna grasslands in Africa. Wagtails are essentially birds of wet grassland, lakesides, and river margins. Several species are resident in Africa, but they are most widespread in Europe and Asia.
One species, the Yellow wagtail, has managed to gain a small foothold in Alaska, but each autumn these birds return across the Bering Sea to winter in Southeast Asia, along with their fellows from the Old World. Members of the most widespread genus, the pipits, are almost worldwide in distribution and are most successful in areas of dry grassland, sub-desert, or open woodland. Many species are strongly migratory, moving from high latitudes towards or across the Equator in winter or from hill and mountain tops down towards the coast.
Wagtails and pipits are mostly small, rather slender birds, with characteristically long tails and long legs. All species have long toes and often very elongated claws, particularly to the hind toe. In most species, the bill is slim and rather long but in long claws it’s rather more robust, to deal with the strong bodies of their mostly beetle prey.
The Golden pipit and the long claws have mostly dull, cryptically colored upper parts. In contrast, they are underparts are strikingly colored, often yellow, and usually with bold dark breast bands. This is used to effect when in the display, during which birds raise their bill to show off their chin and throat and pout their chest.
The wagtails and the pipits have evolved opposite extremes of plumage patterning and coloration, which seems to relate to toothier reproductive behavior. Pipits are very inconspicuously colored, mostly brown, and often heavily streaked, but they have use-ally a very conspicuous song flight and, though rather simple and repetitive, their song is often loud and carries far. In contrast, wagtails are brightly plumed with striking patterns of black and white combinations of bluish, greenish, or olive upper parts and bright yellow or yellowish underparts. As their name implies, these birds often prominently wag their tail which may well serve as an effective territorial signal, to maintain spacing between neighboring birds.
Whilst they have piercing call notes, their songs are mostly rather quiet and used much less frequently than in the pipits. Several wagtail species exhibit very striking racial differences in plumage patterns. In the Yellow wagtail, these differences have led some authorities to split the groups into as manias 14 separate subspecies based on coloration, largely that of the head. However, at the boundaries between different races many birds with intermediate plumage characteristics occur, suggesting a considerable degree of interbreeding.
Wagtails and pipits are extremely adept at catching insects since they form the bulk of the diet of most species. The most sedentary prey is merely picked from amongst vegetation or stones, but more mobile prey may be secured by a sudden lunge, a rapid running pursuit, or by flycatching. The morphology of individual wagtail and pipit species seems to be closely related to the situation in which they most commonly find their prey, and hence to the feeding tech inquest, they most often employ. For example, in wagtails, the lengths of the tail and legs appear to be inversely related. Associated with the proportions of picking or fly-catching feeding activity.
At one extreme the Citrine wagtail has very long legs Anda a short tail, and spends much of its time wading in the shallow margins of lakes and slow-flowing rivers, picking insects and perhaps mollusks from below or on the sure-face of the water. In contrast, the Gray wag-tail has a very long tail and rather short legs. It is found in fast-flowing mountain streams. Often perching on prominent rocks from which it sallies forth to catch insects in flight above water. Here its long tail probe-ably acts as an efficient rudder, enabling complicated aerial maneuvers to be readily accomplished. However, wagtails and pipits are less agile fliers than, for example. Swale-lows, and hence prefer to feed on the least agile flying insects.
The breeding season of some species is closely linked with the times at which suitable prey emerges. Thus Meadow pipits may feed their young on only one or two species of crane fly which occur in great abundance in some upland grasslands and heaths. On the clumsily flying mayflies that emerge Similarly, Gray wagtails may concentrate seasonally from the waters of the rivers they live beside.
Naturally most wagtails and pipits nekton the ground, making a fairly deep nest, often at the base of a clump of concealing vegetation. Some pipits also use holes, in theory, banks of temporary rivers or in small cliff faces, Gray and Mountain wagtails utilize tree roots, holes in riverbanks and bridges, and White wagtails use holes in screens, dry-stone walls, crevices in buildings, and quite often the old discarded nest of another bird species.
Many wagtails and pipits are highly migratory and several species annually traverse the Sahara Desert during journeys between breeding and wintering areas. This may involve them in continuous nonstop flights of over two and a half days’ duration and to achieve this they almost double their body weight by accumulating fat reserves the fuel for the journey) before setting out. In winter many species associate in large flocks. Particularly when roosting at night. This has enabled several species to be caught in large numbers for ringing and other scientific studies.
Once they have located suitable wintering areas during their first year of life, most birds appear to be remarkably faithful to this in subsequent winters. Thus although their average annual mortality is about 50 percent, which is normal for small birds, at least one Yellow wag-tail has been retrapped in its winter roosting West Africa over seven years after it was originally caught and ringed there. This par-titular bird must thus have successfully crossed the Sahara Desert at least 13 times in its lifetime.