130 ANNALS OF SCOTTISH NATURAL HISTORY 



closing months of 1906 continued with us to add a spice to 

 observation ; the Brambling, for instance, remaining in the 

 west (Gareloch) till 24th April, and in the east until the ist 

 of May the last a later date than any previously recorded 

 in these reports. The fine weather in the end of March is 

 connected with the many early dates to be found reported in 

 the following pages ; and though April left a good deal to be 

 desired, the conditions were not such as to discourage our 

 visitors who came in large numbers, Swallows, Sandmartins, 

 Yellow Wagtails, Common Sandpipers in force enlivening 

 our streams in the west at any rate, at a time when in the 

 present year not a single example of the species named was 

 to be seen. There was one exception, however, as the 

 Willow-Wren did not appear in great numbers till May. 

 The boisterous weather of June, it will be found, is claimed 

 to have led to an increase in the number of Swallows in 

 the Outer Hebrides. The absence of abnormal conditions 

 in the last months of the year probably deprived us of the 

 great immigrations which distinguished the same period in 

 1906. The Fair Isle, thanks to the investigations which 

 Mr. Eagle Clarke has continued there, again supplies us 

 with much important and curious matter. We may have to 

 wait some time before we get at the rationale of the occur- 

 rence of Far Eastern and South-eastern species there; but 

 the regular appearance of Northern species like the White 

 Wagtail, Lapland Bunting, and several species of the Finch 

 tribe, we are not unprepared for, and other blanks in our 

 knowledge which these investigations have filled up relate to 

 the passage of such species as the Whinchat, Tree-Pipit, etc., 

 almost or entirely unknown hitherto in the Shetlands. 



Statements have frequently been circulated about the 

 variation in the numbers of certain species of our summer 

 visitors from year to year, but the opportunities which this 

 annual report presents for supplying students with a useful 

 and connected body of data on these interesting but obscure 

 phenomena have not been fully or systematically taken 

 advantage of. It will be found in the present report that 

 there are some statements on this subject which seem to be 

 naturally connected. Further evidence is desired, but care 

 should be taken by observers not to trust to memory 



