230 . AVES. 



which is only assumed in their third or fourth year, a circumstance 

 which has occasioned a great multiplication of species. The female 

 is generally one-third larger than the male, which, on this account, 

 is styled a tarsel, or tercel. We should, first of all, subdivide this 

 genus into two great sections. 



NOBLE BIRDS OF PREY. 



Falco, Bechst. Falcons, properly so called. 



The true Falcons constitute the first, and, in proportion to their 

 size, are the most courageous, a quality which is derived from the 

 power of their arms and wings ; their beak, curved from its base, 

 has a sharp tooth on each side of its point, and the second quill of 

 their wings is the longest, the first nearly equalling it, which ren- 

 ders the whole wing longer and more pointed. From this, also, 

 result peculiar habits : the length of the quills of their wings dimin- 

 ishes their vertical power, and compels them, in a calm state of the 

 atmosphere, to fly obliquely forwards, so that when they wish to 

 rise directly upwards, they are obliged to fly against the wind. 

 These birds are the most docile of all those employed by falconers, 

 who teach them to pursue game, and to return at their call. Their 

 wings are longer than their tails. 



F. communis, Gm.(l) (The Common Falcon.) As large as 

 a hen, and distinguished by a triangular, black moustache on 

 the cheek, larger than that of any other species of the genus 5 

 it varies as to colours nearly in the following manner : when 

 young, it is brown above, the feathers edged with reddish j un- 

 derneath whitish, with longitudinal brown spots. As it increases 

 in age, the spots on the belly and thighs have a tendency to form 

 transverse blackish lines, and the white increases on the throat 

 and root of the neck ; the plumage on the back, at the same 

 time, becomes more uniform, and is of a brown, transversely 

 striped with a blackish ash colour ; the tail is brown above, 

 with pairs of reddish spots, and beneath with pale bands which 

 diminish in width with age ; the throat is always whitej the 

 feet and the cera of the beak are sometimes blue and sometimes 

 yellow. These variations may be followed, Enl. 470, the young j 



(1) We must take especial care not to refer to this species the pretended varie- 

 ties of the Falco communis given by Gmelin. Thus the var . ct, Frisch. 74, is a Buz- 

 zard ; S, Id. 75, is a Booted Buzzard; e, Id. 80, the Falco py gar gus, L.; 6, Id. 76, 

 a Buzzard somewhat paler than usual ; ., Aldrov. 494, a very distinct species, &c. 

 On tlie contrary, the F. islandicus, harbarus 3indperegrinus may all be the Common 

 Falcon at difl'erent periods of moulting. 



