The difference of size between the two sexes in the case of these splendid birds is, as it will be seen, considerable. But both are so superior in speed and strength to any creatures at which they are at all likely to be flown in England, that the list of quarry suitable for the gerfalcon will, with a very few exceptions, serve for the ger tiercel also. This list includes gulls of all kinds, herons, rooks and crows, wood-pigeon, black-game, grouse, partridges, hares and rabbits, wild-duck of all descriptions, Norfolk plover, and all the sea-fowls found on the coasts of Great Britain and Ireland, except swans, and perhaps wild geese. The gerfalcon will also take these latter, as well as kites and cranes, peacocks, ptarmigan, and bustards, at which the best of them may be flown in countries where such birds are to be found in sufficiently open places. It is recorded of Henry, king of Navarre, that he had a gerfalcon which Scaliger declares to have struck down in his sight a buzzard, two wild geese, divers kites, a crane, and a swan (Sir Thomas Browne, cited by Harting, _Bibliotheca Accipitraria_, xxvii.). The flight of the ger is marked by an appearance of power suitable to its size and shape, and combines in an extraordinary degree swiftness and the power of turning readily. When taught to wait on, it does so in majestic style, often at a stupendous height; and its stoop from that direction is so "hard," as the old falconers termed it, or in other words so swift and impetuous, that the quarry is less often clutched and held than struck down with a blow as the hawk passes, and is often found either killed or altogether disabled by the violence of the shock. So great, indeed, is the vehemence with which the ger flies and stoops, that the old masters warned their pupils not to work them long on any occasion, for fear of tiring them, and thus lowering their "pitch," or impairing their powers of mounting.