Birds. 7347 



grown up wild and free, which nearly every hour of his life has to 

 depend on the utility of his wings, either for the purpose of overtaking 

 its prey, or for that of escaping from being caught. 



Laying down, therefore, 100 geographical miles per hour as the 

 rate of flight of birds during distant migration, one keeps — after the 

 above— quite within safe bounds ; and, at this rate, the 1600 geo- 

 graphical miles from Newfoundland to Ireland would be effected in 

 sixteen hours. No ornithologist will doubt for a moment the capabi- 

 lity of a healthy bird to sustain a flight of that duration ; during the 

 long summer days many of the Hirundinidae are on the wing for as 

 long a period, and although their flight may be interrupted by occa- 

 sional rests of very short duration, it is performed in the lower, less 

 buoyant atmosphere, and consists of so many evolutions that most 

 decidedly it must on the whole be much more tiresome than the 

 straight path, in the pure upper regions, of a bird bent on the per- 

 formance of one long pilgrimage. 



Even supposing that birds become exhausted before accomplishino- 

 the passage across the ocean, observations I have made in the vici- 

 nity of this island have fully convinced me that soiall birds, such as 

 thrushes, buntings, finches, &c., are able to rest on the sea, even 

 when a little in motion, and afterwards to resume and pursue their 

 flight with fresh vigour. Of this I shall give the particulars further 

 on ; but, for the present, I return to the above question, by giving an 

 instance of endurance on the wing of a species which, with pretty 

 good certainty, may be said every spring to perform, in the period of 

 one night, a flight of more than 1200 geographical miles, namely, 

 from Egypt to Heligoland; the bird in question being a particular 

 form of bluelhroated warbler {Sylvia ccerulecula, Pallas). 



This pretty little bird, noted not at all either for rapidity or great 

 endurance of flight, has its summer quarters in the high northern 

 latitudes of Sweden, Finland and Siberia ; whereas during the winter 

 months it is staying principally in Egypt. On its spring migration, 

 which takes place during the earlier half of May, the first place north 

 of Egypt where it is to be found with certainty in pretty considerable 

 numbers is Heligoland. Nowhere in the whole intermediate distance 

 is it met with but as a great rarity, not even on the neighbouring 

 north coast of Germany; whilst here in Heligoland 1 have oftentimes 

 obtained it in such numbers that more than twenty of the finest adult 

 male birds have been bought by me in one day, and perhaps the same 

 number by the bird-stuffers of the island. The foregoing admits of 

 one conclusion only, namely, that this little bird performs the passage 



