igS THE SCOTTISH NATURALIST 



were distinctly favourable for the arrival of birds in Britain, 

 an east wind in Norway and a south, merely a delaying 

 wind, in the western North Sea, but the birds seen on the 

 days following were comparatively few, sixteen (28th), three 

 (29th), and five (30th). Obviously a favourable wind is of no 

 account if the birds do not rise on migration ; and this seems 

 to be the explanation, the prime factor in determining a 

 rise being something different from wind, namely, a baro- 

 metrical factor. During the days of this favourable wind 

 the barometer in southern Norway was falling to its lowest 

 limit between the second and third climaxes — the birds did 

 not set out on migration, and no degree of favourable wind 

 could have landed them on the British Coast. 



These conclusions may seem hasty and dogmatic, but 

 I hope to analyse the data and comparisons on which they 

 are based, and which seems to me to justify them, in another 

 paper, since only by a method of strict analysis can we hope 

 to reach any satisfactory conclusion regarding the obscure 

 and elusive factors involved in migration. 



Migrations of the IVaxwings in Britain. — It is difficult to 

 find any general phrase which would cover the kind of 

 movements exhibited by the Waxwings in Britain. Some- 

 times their movements were distinctly erratic, but as a rule 

 there was method in their ways. On a limited area, such as 

 Holy Isle, Mr Watson has recorded that each visitor stayed 

 only a few hours and then continued its journey. But often 

 they stayed for periods of varying duration about the same 

 neighbourhood, returning for several days to the same 

 garden or even to the same bush, until the food-supply was 

 exhausted. As a rule they soon left the coast for inland 

 parts, apparently influenced partly by food-supply and partly 

 by a desire for shelter. These influences, also, seem to have 

 determined to a great degree their subsequent wanderings, 

 for it is clear from several well-marked cases, notably those 

 of the Kelvin Valley and the denes of Berwickshire, where 

 individuals were seen from the 19th November till the end 

 of January, that they followed the valleys. Here it is 

 impossible to disentangle the influences of food and shelter, 

 for it so happens that the sheltered valleys are at the same 



