1911 Encyclopædia Britannica/Sand-grouse
SAND-GROUSE, the name[1] by which are commonly known the members of a small group of birds frequenting sandy tracts, and having their feet more or less clothed with feathers after the fashion of grouse (q.v.), to which they were originally thought to be closely allied; the species first described were by the earlier systematists invariably referred to the genus Tetrao. Their separation therefrom is due to C. J. Temminck, who made for them a distinct genus which he called Pterocles.[2] Further investigation of the osteology and pterylosis of the sand-grouse revealed still greater divergence from the normal Gallinae (to which the true grouse belong), as well as several curious resemblances to the pigeons; and in the Zoological Society's Proceedings for 1868 (p. 303) T. H. Huxley proposed to regard them, under the name of Pteroclomorphae, as forming a group equivalent to the Alectoromorphae and Peristeromorphae. They are now generally regarded as forming a separate sub-order Pterocles of Charadriiform birds, allied to pigeons (see Birds).
The Pteroclidae consist of two genera—Pterocles, with about fifteen species, and Syrrhaptes, with two. Of the former, two species inhabit Europe, P. arenarius, the sand-grouse proper, and that which is usually called P. alchata, the pin-tailed sand-grouse. The European range of the first is practically limited to Portugal, Spain and S. Russia, while the second inhabits also the S. of France, where it is generally known by its Catalan name of Ganga, or locally as Grandaulo, or, strange to say, Perdrix d'Angleterre. Both species are also abundant in Barbary, and have been believed to extend E. through Asia to India, in most parts of which country they seem to be only winter-visitants; but in 1880 M. Bogdanow pointed out to the Academy of St Petersburg (Bulletin, xxvii. 164) a slight difference of coloration between eastern and western examples of what had hitherto passed as P. alchata; analogy would suggest that a similar difference might be found in examples of P. arenarius. India, moreover, possesses five other species of Pterocles, of which, however, only one, P. fasciatus, is peculiar to Asia, while the others inhabit Africa as well, and all the remaining species belong to the Ethiopian region—one, P. personatus, being peculiar to Madagascar, and four occurring in or on the borders of the Cape Colony.
The genus Syrrhaptes, though in general appearance resembling Pterocles, has a conformation of foot quite unique among birds, the three anterior toes being encased in a common “podotheca,” which is clothed to the claws with hairy feathers, so as to look much like a fingerless glove. The hind toe is wanting. The two species of Syrrhaptes are S. tibetanus—the largest sand-grouse known—inhabiting the country whence its trivial name is derived, and S. paradoxus, ranging from N. China across Central Asia to the confines of Europe, which it occasionally invades. Though its attempts at colonization in the extreme W. have failed, it would seem to have established itself in the neighbourhood of Astrakhan (Ibis, 1882, p. 220). It appears to be the “Barguerlac” of Marco Polo (ed. Yule, i. p. 239); and the “Loung-Kio” or “Dragon's Foot,” so unscientifically described by the Abbé Huc (Souvenirs d'un Voyage dans la Tartarie, i. p. 244), can scarcely be anything else than this bird.
The sand-grouse assimilates in general colour to that of the ground, being above of a dull ochreous hue, more or less barred or mottled by darker shades, while beneath it is frequently varied by belts of deep brown intensifying into black. Lighter tints are, however, exhibited by some species and streaks or edgings of an almost pure white relieve the prevailing sandy or fawn-coloured hues that especially characterize the group. The sexes seem always to differ in plumage, that of the male being the brightest and most diversified. The expression is decidedly dove-like, and so is the form of the body, the long wings contributing also to that effect, so that among Anglo-Indians these birds are commonly known as “rock-pigeons.” The long wings, the outermost primary of which in Syrrhaptes has its shaft produced into an attenuated filament, are in all the species worked by exceedingly powerful muscles, and in several forms the middle rectrices are likewise protracted and pointed, so as to give to their wearers the name of Pin-tailed Sand-Grouse.[3] The nest is a shallow hole in the sand. Three seems to be the regular complement of eggs, but there are writers who declare that the full number in some species is four. These eggs are almost cylindrical in the middle and nearly alike at each end, and are of a pale earthy colour, spotted, blotched or marbled with darker shades, the markings being of two kinds, one superficial and the other more deeply seated in the shell. The young are hatched fully clothed in down (P.Z.S., 1866, pl. ix. fig. 2), and appear to be capable of locomotion soon after birth. The remains of an extinct species of Pterocles, P. sepultus, intermediate apparently between P. alchata and P. gutturalis, have been recognized in the Miocene Caves of the Allier by A. Milne-Edwards (Ois. foss. de la France, p. 294, pl. clxi., figs. 1-9); and, in addition to the other authorities on this very interesting group of birds already cited, reference may be made to D. G. Elliot's “Study” of the Family (P.Z.S., 1878, pp. 233–264) and H. F. Gadow, “On Certain Points in the Anatomy of Pterocles” (op. cit., 1882, pp. 312–332). (A. N.)
- ↑ It seems to have been first used by J. Latham in 1783 (Synopsis, iv. p. 751) as the direct translation of the name Tetrao arenarius given by Pallas.
- ↑ He states that he published this name in 1809; but hitherto research has failed to find it used until 1815.
- ↑ These were separated by Bonaparte (Comptes rendus, xlii. p. 880) as a distinct genus, Pteroclurus, which later authors have justly seen no reason to adopt.