150 THE FLIGHT OP BIRDS. 



it may be said to be swift and very uncertain. 



It is notorious how diflFerent the manners of birds are in spring; and 

 hence we must possess a very close knowledge of the manners of the 

 tenants of the air at all times, to be able to distinguish them readily at that 

 season. The Turtle Dove has so much the manner of the Common Pigeon, 

 that he may be easily known, but he jerks along very much after the 

 manner of a skater at full speed on the ice. The motion of the wings 

 of the Snipe genus is very quick and continuous; and the flight of the 

 Common or Whole Snipe very strong and swift, and generally accompanied 

 by very short turns or twists, especially when he rises. These birds have 

 a peculiarity, not I believe observed in any other kind; it is their custom 

 during the summer evenings to fly round in circles at a considerable height 

 over the moors on which they have nests, and at every turn they make 

 to descend suddenly, at which movement the two or three first quill 

 feathers of the wings are strangely agitated, and a loud humming sound 

 is heard. It has been made a question how this sound is produced, but 

 I remember, many years since, taking some pains to clear up the matter, 

 and doing so entirely, at least to my own satisfaction; and I feel quite 

 convinced that it proceeds from the quill feathers of the wings being 

 opposed to the air in a curious and sudden manner at a peculiar angle, 

 I had often heard the drumming sound in warm evenings, and at the dis- 

 tance from which it came it had much the character of the bleating of 

 a sheep; indeed one of the names of this bird, and probably referring to 

 this circumstance, is, as we know, ^'Heather-bleater." But, standing imme- 

 diately under the bird and observing him narrowly, not only was the 

 motion of the wings plainly discernible, but the sound produced by it so 

 palpable in its nature, that I feel convinced any one with the same 

 opportunity of observation, must conclude it to be produced by the air 

 rushing through the outer webs of the feathers at a particular angle, a 

 quivering motion being given to the wings by the bird at the same moment. 

 Every one has heard the rushing sound produced by the swift flight of 

 a bird immediately overhead; this, it must have been observed also, has a 

 tendency to a humming sound; indeed, any surface opposed to the air, with 

 a suflQciently swift motion, will produce this sound, for instance, a top. The 

 exact mode in which the Snipe causes its wing feathers to produce this sound, 

 would not perhaps be very easy to explain, but I am as convinced that 

 she does so produce it, from my frequent and attentive observation, as I 

 can be of any fact whatever which I have seen with my eyes and heard 

 with my ears. 



All the Lark tribe have an easy manner of flight, their wings being 

 generally large, and the tertials very long; most of them open and shut 

 the wings at intervals; but with the smaller kinds of Pipit and Titlark 



