Studies of Less Familiar Birds 116. Crested Lark by I

Studies of less familiar birds 116. Crested Lark By I. J. Ferguson-Lees Photographs by lb Trap-Lind (Plates 6-7) WE HAVE ONLY two photographs of the Crested Lark (Galerida cristatd) here, but they show the salient features very well. The species gets its name from the long upstanding crest which arises from the middle of its crown and which is conspicuous even when depressed. Many other larks have crests and inexperienced observers are sometimes misled by that on the Skylark (Alauda arvensis) when they see it raised and at close range, but the crest of the Crested Lark is really of almost comical proportions. The two plates also illustrate several other characters of this species and attention is drawn to these in the caption on plate 7. Crested Larks have a somewhat undulating flight, rather like that of Woodlarks (Lislbfa arborea), and a characteris tic outline from their short tails and broad, rounded wings. In Britain the Crested Lark is a surprisingly rare vagrant which has been recorded on less than fifteen occasions. The last two accepted observations were on Fair Isle in 1952 (Brit. Birds, 46: 211) and in Devonin 1958-5C) (Brit. Birds, 53: 167, 422), though it should be added that the species has almost certainly also occurred in Kent on at least two occasions in the last five years. Thus, while so many other birds formerly regarded as very rare wanderers to Britain are now known to be of annual occurrence in small numbers—the Melodious Warbler (Hippolais polyglottd) is one such example—the enormous increase in experienced observers has failed to raise the number of records of the Crested Lark. This is all the more surprising when one remembers that it breeds in many parts of the Continent as far north as southern Norway and Sweden (though apparently not now in Finland) and is thus found on the same latitude as Scotland. It also nests in the northern half of Africa and across much of southern Asia to northern India, north China and Korea. In many places the species is resident, but Dementiev and Gladkov (1954) quoted Stanchinski (1926) in saying that it is sedentary in the U.S.S.R. only where the snow is on the ground for less than 144 days in the year, and Vaurie (1951) men tioned several published cases of migratory movements. Labitte (1957) cited two recoveries within six months of birds ringed as nestlings; in that time these had respectively travelled 1,500 kilometres SSW from Sweden into France and 750 kilometres SW from Belgium 37 BRITISH BIRDS into France. Evidence of passage has also been obtained as close to Britain as Cap Gris Nez (Redman 1956). Many geographical forms have been separated. Dementiev (1954) mapped 37 sub-species and Meinertzhagen (1951) was able to list no fewer than 5 6 which were more or less generally recognised (thougn he himself accepted only 20 of them). Even for a bird with such a wide range across three continents, this is a very high number of distinct races. In general, populations of the Crested Lark become paler, greyer and more sandy from Europe to central Asia and then the dine is reversed; there are similar clines in wing-length and bill-length. Vaurie (1951) suggested that "its geographical variability may be due to a fairly high degree of susceptibility to varying conditions of aridity and humidity and, in some cases, to variations in the coloration of the soil." The remarkable extent to which the plumages of larks vary from sandy to brown, grey or red according to the habitat in which they are found was also discussed by Vaurie and he referred to a number of other publications on this subject; this correlation with soil colour is particularly marked in Africa. Vaurie (1959) accepted 22 races of the Crested Lark in the Palearctic, of which four are found in Europe. These are the typical cristata, the more faded pallida from Spain and Portugal, the browner meridionalis from the southern Balkans and Italy, and the greyer caucasica from Crete, Rhodes and further east. The Crested Lark is a bird of open country, but it is much less addicted to grassland and crops than, for example, the Skylark. It prefers arid and barren ground, particularly dusty areas, desert edges, dry steppe, arable farmland, railway embankments and the edges of unmetalled roads. In some parts of its range it is found in rocky habitats in quite mountainous country, but it is generally a bird of the lowland plains. It also tends to be absent from places where there is much growth of shrubs and bushes. In central Europe, and in parts of the south, it is particularly common at the edges of villages and towns where the roads are dusty and rough. In Holland it can be seen near railway stations and demolished houses. In Poland it nests on bomb sites in the centre of Wroclaw. Dementiev and Gladkov (1954) similarly described it as much more common in the U.S.S.R. near human habitation than on the open steppe. There are three other species of Galerida. Two- of these, G. deva and G. malabarka, are confined to India, but in north-west, north and east Africa, and in Spain, Portugal and the very south of France, the range of the Crested Lark overlaps with that of the very similar Thekla Lark (G. tkeklae). In fact, the two species may be found closely adjacent, though the Thekla appears to be more partial to rocky or scrub-covered plateaux and slopes dotted with bushes and trees. It also seems to extend to quite high altitudes, but is perhaps most common 38 CRESTED LARK STUDIES within a few dozen miles of the coast. Generally speaking, the Thekla is more a bird of hills, hillocks, sea-cliffs, rocks and bushes, but it also frequents sand-dunes and in the semi-deserts of the Coto Donana in Spain it inhabits the oases near the coast as well as the scrub-covered plain inland. It may be that the presence of the Thekla causes the Crested to contract its choice of habitats, and that otherwise the latter fills the niches of both to some extent. The situation is complicated by the fact that the two species are very similar in the field. In southern Europe, the Crested is generally more sandy than the darker and greyer Thekla, but both are so variable that much more than this is needed to separate them. It is, indeed, necessary to take into account a whole series of slight differences, hardly any of which can be regarded as reliable on their own. Niet- hammer (1955) also emphasised this point, but his choice of characters was misleading. He considered the most reliable features to be the Crested's larger size, its sandier colouring, the less distinct streaks on its breast and differences in habitat and voice; he also said that the Crested was much more shy. Habitat and colouring are both rather variable, however, as we have seen, and size is notoriously difficult to judge unless a direct comparison is possible; in some parts of Spain, too, Crested (and Thekla) Larks are so tame that they feed at the edge of the road while one walks by. The streakings on the breast are a very useful pointer, however. Those of the Thekla are much more distinct and the marks are quite conspicuous at, say, 30 yards when those of the Crested Lark appear as little more than smudges. The Thekla also has a smaller and more solid-looking bill, and a less melodious and varied vocabulary, but the best distinction between the two lies in the colour of the underwing. This is strikingly orange- buff in the Crested Lark and grey in the Thekla. Unfortunately, it is often difficult to see the underwing unless the observer gets the bird to fly past when he has the light behind him; however, in such conditions the wings of the Crested Lark seem to have quite a rufous glow and those of the Thekla appear silvery-grey. The normal call of the Crested Lark is a liquid and musical whistle of four syllables (or sometimes three), written in The Handbook as "whee-whee-«fe<?oo". This call was discussed at some length by- Barrett et al. (1948), as a result of their observations during the war in German prison camps, the vicinities of which provided ideal habitats for these birds. They likened the rhythm of the note to "God Save the Queen". They found that it was used throughout the year, partic ularly in March-May and August-October, but rather less in winter. It serves to advertise territory and is also uttered in sexual chases, as well as providing contact between feeding pairs and parties. Depending on whether it is a display or contact note, it varies from 39 BRITISH BIRDS shrill and loud to soft and sweet. When uttering the shrill version, the bird stands upright with its crest raised. The normal alarm is a pure-toned whistle of two syllables, a long slow note increased in pitch at the end; this is usually delivered on the ground, the bird crouching low as it normally does before taking flight. Barrett et al. also described three other juvenile, pursuit and challenge calls, in addition to soft and full song. The Handbook describes the song as "lacking continuity and vehemence of Sky-Lark, delivered more haltingly and mostly in brief phrases, produces inferior and somewhat monotonous effect", but I agree with Barrett et al.

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