MOTIONS OF BIRDS. 



I have somewhat to advance on the different manners in 

 which different birds fly and walk ; but as this is a subject 

 that I have not enough considered, and is of such a nature as 

 not to be contained in a small space, I shall say nothing- 

 farther at present.* 



* See Letter LXXXIV. To the Hon. Daines Barrington. 



There is much variety in the flight of birds ; some fly by jerks, 

 closing their wings every third or fourth stroke, which produces an 

 undulatory motion, as may be observed in the flight of woodpeckers 

 warblers, wagtails, and most other small birds ; others pursue a smooth 

 and even course ; while others, again, are buoyant, without perceptible 

 motion, as the kite, kestril, and many of the hawk tribe. The greater 

 number of birds fly with their legs drawn up, and their neck extended ; 

 others again, from their great length of neck, and its consequent weight, 

 are obliged to contract, or bend it in flight, for the purpose of bringing the 

 centre of gravity on the wings, in aid of which the legs are stretched 

 behind, as exemplified in the heron, stork, and bittern. Others fly with 

 protruded necks, but are compelled to throw out their legs behind, as the 

 goose, duck, and other aquatic birds. 



Aquatic birds, and those termed waders, run in the ordinary manner, 

 by alternately placing one foot before the other ; but nearly all the smaller 

 birds jump, or hop along, as if their legs were united. The crow, 

 starling, lark, and wagtail, are regular walkers. ED. 



" The flight of a strong falcon," says Dr Shaw, "is wonderfully swift. 

 It is recorded that a falcon belonging to the Duke of Cleve, flew out of 

 Westphalia into Prussia in one day ; and in the county of Norfolk, a 

 hawk has made a flight at a woodcock near thirty miles in an hour." 



" But what are these," says Professor Rennie, " compared to the actual 

 velocity and continuance of the falcon that is recorded to have belonged 

 to Henry IV. King of France, which escaped from Fontainbleau, and 

 in twenty-four hours after was killed in Malta, a space computed to be 

 not less 'than one thousand three hundred and fifty miles ! a velocity 

 equal to fifty-seven miles in an hour, supposing the hawk to have been 

 on the wing the whole time. But as such birds never fly by night, and 

 allowing the day to be at the longest, or to be eighteen hours light, this 

 would make seventy-five miles an hour. It is probable, however, that he 

 neither had so many hours of light in the twenty-four to perform the 

 journey, nor that he was retaken the moment of his arrival, so that we 

 may fairly conclude much less time was occupied in performing this 

 distant flight," 



We do not agree with the opinion entertained by Professor Rennie, that 

 the falcon in question did not fly by night. Although the birds of this 

 tribe are diurnal, still there must be instances of their flying by night, as 

 in the case above referred to. We would ask, where did he rest during 

 the night in crossing the Mediterranean? Birds which make long 

 migrations,' must fly by night as well as by day in crossing a great extent 

 of ocean. 



Audubon says, " The passenger pigeon (columba migrator ia) moves 

 M'ith extreme rapidity, propelling itself by repeated flaps of the wings, 

 which it brings more or less near to the body, according to the degree of 

 velocity which is required. Like the domestic pigeon, it often flies 



