Gos-Hawk
GOS-HAWK, i.e. goose-hawk, the Astur palumbarius of ornithologists, and the largest of the short-winged hawks used in falconry. Its English name, however, has possibly been transferred to this species from one of the long-winged hawks or true falcons, since there is no tradition of the gos-hawk, now So called, having ever been used in Europe to take geese or other large and powerful birds. The genus Astur may be readily distinguished from Falco by the smooth edges of its beak, its short wings (not reaching beyond about the middle of the tail) , and its long legs and toes though these last are stout and comparatively shorter than in the sparrow-hawks (Accipiter). In plumage the gos-hawk has a general resemblance to the peregrine falcon, and it undergoes a corresponding change as it advances from youth to maturity the young being longitudinally streaked beneath, while the adults are transversely barred. The irides, however, are always yellow, or in old birds orange, while those of the falcons are dark brown. The sexes differ greatly in size. There can be little doubt that the gos-hawk, nowadays very rare in Britain, was once common in England, and even towards the end of the 18th century Thornton obtained a nestling in Scotland, while Irish gos-hawks were of old highly celebrated. Being strictly a woodland-bird, its disappearance may be safely connected with the disappearance of the ancient forests in Great Britain, though its destructiveness to poultry and pigeons has doubtless contributed to its present scarcity. In many parts of the continent of Europe it still abounds. It ranges eastward to China and is much valued in India. In North America it is represented by a very nearly allied species, A. atricapillus, chiefly distinguished by the closer barring of the breast. Three or four examples corresponding with this form have been obtained in Britain. A good many other species of Astur (some of them passing into Accipiter) are found in various parts of the world, but the only one that need here be mentioned is the A. novae-hollandiae of Australia, which is remarkable for its dimorphism one form possessing the normal dark-coloured plumage of the genus and the other being perfectly white, with crimson irides. Some writers hold these two forms to be distinct species and call the dark-coloured one A. cinereus or A. rait. (A. N.)
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)
