SPARROW HAWK. 351 



Variations. — Males vary in length from twelve to thirteen 

 and a half inches, and proportionally in bulk. In adults the 

 colour of the upper parts scarcely varies, but on the lower the 

 red bars vary in breadth and purity. The largest females are 

 seventeen inches long, the smallest fourteen. Very old indi- 

 viduals are sometimes nearly as blue on the back as the males, 

 but generally greyish-brown, or hair-brown tinged with bluish- 

 grey, is the prevailing tint. The length of the alimentary 

 canal varies considerably. The iris varies in the males from 

 yellow to orange and even yellowish-red. 



M. 



(Esophagus in length. . . . 4^ 



Crop in width ... 1 



Stomach in diameter — 1/^ 



Intestine in length SO 



Coeca -^^ 



Rectum 3^ 



Cloaca in width — 



The individual of which the intestine was only nineteen 

 inches long is mentioned in my work on the Ilapacious Birds 

 of Great Britain as the smallest seen by me, and only twelve 

 inches in length. Facts like these shew that in birds the length 

 of the intestinal canal varies in birds as much as in quadru- 

 peds. The scutella are pretty regular as to number in this 

 species. 



Habits. — The manner of life of this elegantly formed and 

 marvellously agile little hawk is better known than that of the 

 congenerous Goshawk, it beinw the most common and most 

 extensively dispersed of our native species of diurnal plunderers. 

 In spirit, activity, dexterity, and daring, it has no superior, 

 and in these respects contrasts strongly with the Eagles and 

 Buzzards, which yet are not sluggish birds, although we are 

 apt to consider them as such, when we compare them with the 

 Falcons. The ground, the tree, the fence-rail, or the stone 

 wall, merely aftbrd it a resting-place, or a point of observation, 



