Saturday, 14 January 2017

Spain 12: An exaltation of Larks

After covering so many species on my trip to Spain we finally arrive at the passerines, starting with the larks. This is an almost entirely Old World group, with only a single species, the Shore or Horned Lark Eremophila alpestris found in North America.

Larks are almost entirely open country birds, found in grassland through to true desert depending on the species. The bulk of the diet is seeds, often at the larger size range such as cereal grains, although they also feed on insects and will often concentrate on insects when raising their young.

Larks almost all nest on the ground and lay 2-6 eggs in a clutch. The nest is a scrape in the ground and often concealed amongst grass tussocks in the grassland species. The young leave the nest before they can fly to forage on the ground while still guarded by at least one of the parents.

Of course, larks are most famous for their song. In the species which live in habitats with at least some tall vegetation they may sing from a perch, but they may also sing from the ground or most often while in flight. The song flights of different species differ in the shape of the song flight, how high the displaying male flies, and other details.

The most familiar of all larks is the Eurasian Skylark Alauda arvensis. Famed in poetry and an inspiration for classical music, it has a vast range, with different subspecies being found from Great Britain east as far as Japan and south to North Africa. As a result of peoples’ fondness for its song, it has been introduced to both Australia and New Zealand, and also to the Hawaiian islands and Vancouver island. It is a classic bird of cereal farmland, but modern intensive agriculture reduces the supply of insects it needs for raising its young. Despite this it is listed as Least Concern by the IUCN.
Thekla Lark
The Thekla Lark Galerida theklae is one of two species in it genus that we encountered. It is basically an African species on the north edge of its range in the Iberian peninsula. It prefers drier habitat to the slightly larger Skylark, with patches of bare ground, dry grassland and some scrub. It may sing in flight, from the ground or from a perch. It appears to be declining in Spain, but given its vast range in Africa it is still listed as Least Concern.
Crested Lark
In the same category is the other Galerida species we encountered, Crested Lark G, cristata. This has an even bigger range than Thekla Lark, extending from Western Europe (although not in the British Isles) across to India and China, although they do not reach Japan. There are numerous subspecies, a result of its mainly sedentary nature. Perhaps because of its long exposure to agriculture they are often found close to farmland and also industrial areas where there is both bare ground and suitable foraging areas.
By contrast to the grassland loving Crested Lark, the Woodlark Lullula arborea is rather aberrant for a lark in that it uses wooded areas, for which reason we found them at the start of the trip in the Pyrenees. They still feed on the ground, but prefer clearings in forests and young forestry plantations rather than wide open spaces. Their range is not as extensive as the other larks in this post, being essentially European but extending east as far as western Russia and Iran. In Britain it has been affected by loss of heathland habitat and is now more or less restricted to southern England.
Calandra Lark
One of the more distinctive larks we found, Calandra larks Melanocorypha calandra are very sociable outside the breeding season and we found one flock of over 100 birds. In flight they are quite distinctive, showing dark underwings and black sides to the breast. Basically a bird of steppe, they are found from southern Europe east to Turkey, where they are replaced into central Asia by Bimaculated Lark M. bimaculata.
Lesser Short-Toed Lark
Finally, the most desert adapted of the larks we found is the Lesser Short-Toed Lark Alaudala rufescens. This is found in open desert and semi-desert across North Africa and the Middle East, and like the Thekla Lark it is on the north edge of its range in Spain. Like the other larks we encountered, it is listed by the IUCN as Least Concern.

The vast majority of lark species listed on the IUCN Red List are listed as Least Concern. However, most lark species tend to be quite sedentary rather than true migrants, mostly just dispersing after the breeding season. As a result they often have multiple localised subspecies which may be affected by changes in agricultural practise, desertification, overgrazing or climate change. Their preference for open country and farmland means that many however are familiar to people, and the beauty of many of their songs means that as a group they are easier than many birds to raise popular support for their conservation.

(Images from Wikipedia)

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