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BIRDS, 



the case of several species which have lately become commoner in 

 the north-east of Scotland, this increase is a direct result of a 

 continental overflow and consequent migration direct upon the 

 coasts of Great Britain, a great migratory ' fan-like ' wave, first 

 impinging upon our more southern coasts, with its southern or 

 left wing, as it were, and shortly afterwards reaching its more 

 northerly extensions. But it is only by a careful study of the 

 dispersal of single species under varying conditions that we can 

 expect to throw light upon such questions ; and only by large 

 accumulations of statistics and subsequent comparison of details 

 that any natural laws can be definitely arrived at.^ 



In 1893 we did not add much to our previous notes upon the 

 Crested Tit. Mr. William Evans found the nest inside the iron 

 standard or straining-post of a railway fence, and a nest and five 

 very hard set eggs was sent to Harvie-Brown, for the Edinburgh 

 Museum, from a locality near where we ourselves found another 

 nest. The stump of the wooden post of a railway fence containing 

 the latter nest is now in the Edinburgh Museum. 



Outside the valley of Spey, yet still within our area, we have, 

 as has been said, scarcely any records. There is a note of one 

 having been seen as low down as Gordon Castle {Fauna of Moray ^ 

 1844), and a more recent one, viz. 1893, of a pair seen in July by 

 the Eev. Mr. Birnie of Speymouth, who, when driving through the 

 Glen of Eothes, saw ' a pair at close quarters, and could not have 

 been mistaken ' {viva voce and in lit. to Harvie-Brown). Both 

 these occurrences must as yet, we believe, only be considered as 

 ' vagrancy,' or possibly pioneer movements of an increasing species, 

 if what we have related of its supposed increase be correct. If it 

 be desired to artificially aid its chances of increase, we would 

 recommend that lairds who desire it should instruct their foresters 

 to spare the old decaying stocks, and even further assist them by 

 making auger-holes in useless timber. We have done this suc- 

 cessfully for other species of Tits. 



^ In this connection we would desire specially to direct attention to our articles 

 upon the following species as illustrating our views, viz. : — Crested Tit ; Marsh Tit ; 

 Great Spotted Woodpecker ; Honey Buzzard ; Stock Dove ; Sandwich and Roseate 

 Terns ; and a few others. We have specially and exhaustively, we think, studied 

 the subject of the dispersal of the Stock Dove, Starling, Tufted Duck {Annals of 

 Scottish Natural History, 1896), and several other single species, with a view to 

 arriving at some general law of dispersal. 



