MIGRATION AND WEATHER 97 



wind, and yet travelling along at nearly their 

 normal speed, at right angles to their position " 

 (46). Mr Tomison mentions rooks, daws and hooded 

 crows driven to Sule Skerry by south-east winds 

 in March, leaving two days later in a westerly gale. 

 They, at any rate, did not object to a strong wind 

 which was in the right direction. 



I have mentioned Mr F. J. Stubbs' paper on the 

 " Use of Wind " (50), and I believe that there is 

 much more in it than is actually proved by low-level 

 observations. I doubt if birds always intentionally 

 make use of strong winds, currents which would carry 

 them for great distances at a considerable speed, but 

 the preliminary ascent may be to search for these 

 currents. Cyclonic and anticyclonic winds, even 

 when at an altitude of some thousands of feet, would 

 carry them easily, and probably it is the wind-borne 

 individuals, parties, or even hosts, which drop for 

 a refuge to the first island they see when carried far 

 from their migratory path. They are carried rather 

 than drifted from their pathway, borne in the moving 

 current whether they wish it or not. Provided that 

 the cyclonic winds are fairly steady in direction and 

 force, sweeping round and inwards towards their 

 centre, we may in imagination trace the pathway 

 of our so-called lost wanderers to far distant islands ; 

 without many more upper-air observation stations, 

 we cannot actually prove the route. 



G 



