4 Stuhbs, The Use of Wind by Migrating Birds. 



Most of us, especially outdoor observers, form con- 

 ceptions of the wind which are altogether wrong. We 

 are apt to look upon it as a seething current, and we pity 

 the poor birds that are carried about by it. The substi- 

 tution of the word air for ivind in all matters relating to 

 the flight and migration of birds would prevent a great deal 

 of misunderstanding. There can be no doubt that if a bird 

 cannot find shelter it will be more comfortable on the 

 wing than on the ground during the progress of a storm. 

 Mr. T. A. Coward tells me that during a storm of unusual 

 violence the ducks on a Cheshire mere sprang into the air, 

 heads to wind, and fleiu at full speed in the teeth of the gale, 

 thereby keeping their places over the middle of the mere, 

 to the surface of which they dropped as soon as the 

 sudden storm was over. Their reason for this manoeuvre 

 was, obviously, to be out of the danger of being between 

 two conflicting elements, the stationary water and the 

 moving air. In the air they made no progress against the 

 wind, but had they flown with it, a few minutes would 

 have sufficed to place many miles between them and the 

 water they were so loth to leave.* This, I think, is the 

 explanation of the conduct of the Gulls mentioned by 

 Mr. Clarke. The bird, then, can fly about in any direction 

 in this wind, but it must be remembered that the whole 

 body of air is moving in some definite direction which 

 may or may not coincide with that in which the bird 

 happens to be flying. If the wind blows from east to 

 west at 50 miles an hour at an altitude of 5,000 feet — and 

 migration is carried on at far greater heights than this — 

 and the bird is capable of flying through the air at 50 

 miles an hour, its net velocity, between points on the 

 earth's surface, if it flies from east to west, would be 100 



*I saw these mctliods adopted by the Gulls and Hooded Crows during 

 the blizzard which raged on the East Coast on March 6th, 1909. 



