CONTINENTAL RACIAL FORMS, ETC. 123 



CONTINENTAL RACIAL FORMS OF SCOTTISH 

 BREEDING BIRDS AND THEIR OCCUR- 

 RENCES IN SCOTLAND. 



By Leonora Jeffrey Rintoul, H.M.B.O.U., and 

 Evelyn V. Baxter, H.M.B.O.U. 



( Concluded from page 106.) 



The Northern Willow-warbler {Phylloscopus trochi- 

 lus eversmamii) is probably a regular passage migrant along 

 our coasts, but is difficult to distinguish from our common 

 breeding bird, and is consequently much overlooked. In 

 Scotland specimens have been obtained in Haddington and 

 Kirkcudbright, on the Isle of May, and in Shetland. This 

 form is also recorded as having been seen at the Mull of 

 Galloway in May 191 3. This Willow-warbler, which breeds 

 in N. E. Russia and Siberia, differs from our breeding bird 

 in having a longer wing — 68-72 mm. in the males, 64-66 mm. 

 in the females, the type usually 66-70 mm. The first quill 

 is usually longer or broader than in P. t. trocJiilus^ and often 

 measures 18-18-5 "im. Dr Hartert says that in spring and 

 summer the colouring is greyer and less greenish than in 

 our birds, and in autumn the difference of colour seems to 

 be very trifling. This colour distinction, however, is not, 

 in our experience, one which can be relied upon, as many 

 of the Willow-warblers killed at the Isle of May lantern, in 

 spring, were totally devoid of any greenish shade in their 

 plumage, and yet had remarkably short wings. We were 

 greatly interested in these curious little grey-brown Willow- 

 warblers, and showed them to Dr Hartert, who agrees with 

 us in referring them to the typical form, P. t. trochilns. 



The typical SONG-THRUSH {Turdiis philomelus philoinehis) 

 breeds in Europe generally and in Western Siberia. It 

 occurs on the east coast of Scotland in very large numbers 

 during the autumn migration period, and also in Orkney 

 and Shetland. This race has been taken at the Mull of 

 Galloway and Little Ross lanterns, and Mr Eagle Clarke 

 records it as a winter visitor to the Outer Hebrides. It is 

 probably a winter visitor to other parts of Scotland, but 



