LETTERS 



To the Editors of British Birds. 



BRITISH SONG-THRUSHES. 



Sirs, — I wish to say a few words about our " British Song-Thrushes." 

 I care not whether their name be T. musicus — auctoruni plurimorutn — 

 or T. philomelos, in this connection, because " British Song Thrushes " 

 {sic) will do quite as wolh 



What I desire to refer most directly to is : the differences which 

 exist between the usual typical olive-backed British-nesting Song- 

 Thrush and that variety which is found nestmg tliroughout the Outer 

 Hebrides. 



The exceedingly dark olive — almost a smoky-black — is most con- 

 spicuous. No good observer in the field can fail to see this even at 

 a distance of a fifty -yards rise, out of the heather, and during the bird's 

 quick flight of a few yards further. 



Now, Dr. Hartert has as yet, I think, only got so far as to distinguish 

 between our British home-bred Song-Thrushes and others of continental 

 localities. May I be permitted to make one more step — forward ? 

 (or otherwise — ). I clearly distinguish between our Hebridean home- 

 bred Song-Thrushes and those which we have with us here in our 

 central districts and on the mainland as a whole. I cannot, from 

 memory or field notes, say what other shades of olive tints occur in 

 the backs of Song-Thrushes in other parts of England, or in Britain north 

 of Tweed. But I am sure that I can point my finger at yet one other 

 colour of back in Scotch-bred Song-Thrushes, and that on certain jDor- 

 tions of the east coast of Scotland, taking the month of May as choice 

 of a right time to make the observation. Again, at a distance of thu'ty 

 to fifty yards the almost absence of olive at all on the backs of the birds 

 flying away from the observer was quite as conspicuous, and eciually 

 startling, as was the deeper tone of olive (or smoky-blackness) of the 

 backs of those of the Western Isles, as distinguished from the typical 

 olive-backs of our general mainland birds. 



Here, then, we have three grades or colour-forms : (a) On the east 

 side of Scotland — conspicuously on the east of Forfar and among the 

 sand-dunes there; (h) the usual central or (?) typical British form; 

 and (c) the dark — conspicuously dark — olive or sooty -bluey -black- 

 backed birds of the west. 



The late Professor A. Newton used to say, " We may soon have 

 a new ' sub-species ' for every parish." But it is a long time ago, and 

 many tides have flowed and ebbed, since Professor Wm. Macgillivray 

 resided in the Outer Hebrides and remarked the " dark - backed 

 Thrushes " of the Isles as compared with those he knew in " Dee " 

 and on the mainland of Scotland. And many later writers have also 

 placed strong emphasis upon their own similar observations. Thus, 



