Page:Encyclopædia Britannica, Ninth Edition, v. 6.djvu/652

018 CROW distinct Family (Garrulidce), though it seems hardly possible to separate them even as a Subfamily from the Pies (Pica and its neighbours), which lead almost insensibly to the typical Crows (Corvince.) Dismissing these subjects for the present, it will perhaps be most convenient to treat of the three groups which are represented by the genera Pyrrhocorax or Choughs, Nucifraga or Nutcrackers, and Corvus or Trua Crows in the most limited sense. Pyrrhocorax comprehends at least two very good species, which have been needlessly divided generically. The best known of them is the Cornish Chough (P, graculus), formerly a denizen of the precipitous cliffs of the south coast of England, of Wales, of the west and north coasts of Ireland, and some of the Hebrides, but now greatly reduced in numbers, and only found in such places as are most free from the intrusion of man or of Daws (Corvus monedula), which last seem to be gradually dispossessing it of its sea-girt strongholds, and its present scarcity is probably in the main due to its persecution by its kindred. In Britain, indeed, it would appear to be only ono of the survivors of a more ancient fauna, for in other countries where it is found it has been driven inland, and inhabits the higher mountains of Europe and North Africa. In the Himalayas a larger form occurs, which has been specifically distinguished (P. himalayanus) , but whether justifiably so may be doubted. The general colour is a glossy black with steel-blue reflections, and it has the bill and legs bright red. 1 The remaining species (P. alpinus) is altogether a mountaineer, and does not affect a sea-shore life. Otherwise it frequents much the same kind of localities, but it does not occur in Britain. The Alpine Chough is somewhat smaller than its congener, and is easily distinguished by its shorter and bright yellow bill. Remains of both have been found in French caverns, the deposits in which were formed during the " Reindeer Age." Com monly placed by systematists next to Pyrrhocorax is the Australian genus Corcorax, represented by a single species (C. melanorhamphus), but osteologtsts must be further con sulted before this assignment of the bird, which is chiefly a frequenter of woodlands, can be admitted without hesita tion. Nucifraga is another very distinct form of Corvidce, peculiar to the Old World, and best exemplified by tho European Nutcracker (N~. caryocatactes), while in the New World it is somewhat remotely represented by the genus Picicorvus, of which only one species (P. columbianus), until lately very rare in collections, and only inhabiting the western slopes of the Rocky Mountains, is known. The Common Nutcracker has a wide range in tho Palsearctic Region, chiefly keeping to subalpine or subarctic pine-forests, and feeding on the seeds of one or another species of fir. It seems nowhere to be numerous, though roving bands of seventy or a hundred have been occasionally observed. It has long been known as a rare straggler to the British Islands, but little was ascertained of its economy till some fifteen years ago. It has now been discovered to breed, though in small numbers, in some of the denser forests of Middle Sweden, on the island of Bornholm, and in the Bavarian and Tyrol ese mountains. It appears to build its nest and lay its eggs very early in the year, long before the snows have disappeared, and this fact, coupled with that of its becoming in the breeding season one of the most silent of birds, when at other times it is rather noisy than not, will account for the mystery which enwrapped its domestic arrangements not having been sooner dispelled. 1 Hence the "russet pated choughs" of Shakespeare, an expression which has much exercised many of his commentators, who did not see that "pated "meant "patted" or footed (cf. the heraldic croix patee), instead of having anything to do with the bird s head, which is as black ns that of a Eaven. See Nature, v. p. 160. Considerable difference has been observed in the form and size of the bill of examples of this species, but this is now supposed to depend on the sex that of the cock being stout and short, while in the hen it is long and thin. 2 The bird is about the size of a Jay, and of a dark sooty-brown colour spangled with white, nearly each body-feather ending in a tear-shaped patch of that colour. Besides the European species, which also extends into Northern or Central Asia, three others, very nearly akin to it, have been described from the Himalayas. Of their American cousin, Clarke s Crow, as it is called (Picicorvus columbianus), an excellent account has been given by Dr Coues (Ibis, 1872, pp. 52-59). Coming now to what may be literally considered Crows, attention must be mainly directed to the Black or Carrion- Crow (Corvus corone) and the Grey, Hooded, or Royston Crow (C. comix). Both these inhabit Europe, but their range and the time of their appearance are very different. Without going into minute details, it will suffice to say that the former is, speaking generally, a summer visitant to the south -western part of this quarter of the globe, and that the latter occupies the north-eastern portion an irregular line drawn diagonally from about the Firth of Clyde to the head of the Adriatic roughly marking their respective distribution. But both are essentially emigrants, and hence it follows that when the Black Crow, as summer comes to an end, retires southward, the Grey Crow moves downward, and in many districts replaces it during winter. Further than this, it has now been incontestably proved that along or near the boundary where these two birds march they not infrequently interbreed, and it is believed that the hybrids, which sometimes wholly resemble one or other of the parents and at other times assume an interme diate plumage, pair indiscriminately among themselves, or with the pure stock. Hence it has of late seemed to many ornithologists who have studied the subject, that these two birds, so long unhesitatingly regarded as distinct species, are only local races of one and the same dimorphic species. No structural difference or indeed any difference except that of range (already spoken of) and colour can be detected, and the problem they offer is one of which the solution is exceedingly interesting if not important to zoologists in general. 3 The mode of life of the Crows needs not to be described. Almost omnivorous in their diet, there is little edible that comes amiss to them, and, except in South America, they are mostly omnipresent. The number of species described is considerable, but doubtless should and will be ruthlessly curtailed when a revision cf the group is undertaken by any ornithologist working with proper materials. The Fish-Crow of North America (C. ossifragus) demands a few words, since it betrays a taste for maritime habits beyond that of other species, but our own Crows of Europe are not averse on occasion to prey cast up by the waters, though they will hardly draw it thence for themselves. The so-called " Hooded Crow " of India (C. eplendens) is not very nearly allied to its European namesake, from which it can be readily distin guished by its smaller size and the lustrous tints of its darkest feathers, while its confidence in the human race has been so long encouraged by its intercourse with an unarmed and inoffensive population, that it becomes a plague to the European abiding or travelling where it is abundant. Hardly a station or camp in British India is 3 An exactly similar sexual distinction is observable in the Huia of New Zealand (Helerolocha), which was for a long time included among the Corvidce, but is now referred to the Starlings (Siurnidce.) 3 As bearing upon this question may be mentioned the fact that the Crow of Australia (C. australis) is divisible into two forms or racea, one having the irides white, the other of a dark colour. It is stated

that they keep apart and do not intermix.