CONTINENTAL RACIAL FORMS, ETC. 105 



Shetland. Doubtless the immigrant Goldcrests, which some- 

 times occur in such numbers all down our east coast, also 

 belong to the typical form. The status of this bird, in 

 Scotland, is insufficiently known, and further definite records 

 are much to be desired. A large immigration of Goldcrests 

 is a most wonderful sight. When they arrive, which in our 

 experience is always with an easterly or south-easterly 

 wind, the poor little birds are often so tired as to allow 

 themselves to be picked up in the hand. They are strongly 

 attracted by light, and are among the most frequent visitors 

 to the lighthouse lanterns. They are by far the tamest 

 and most fearless of all the migrants, and will perch on the 

 rocks and garden walls within reach of one's hand. They 

 look strangely out of place in those barren islets, creeping 

 about on the great rock faces and swarming on the grassy 

 plateaux. 



In Northern and Eastern Europe we find a larger, longer- 

 winged form of the Chiffchaff. The SCANDINAVIAN 

 Chiffchaff {Phylloscopus collybita abietinus) occurs in Scot- 

 land as a passage migrant both in spring and autumn. The 

 wing measurement is 62-67-3 ni^i- in the males, 56-60 mm. 

 in the females ; in the Common Chiffchaff the wing measures 

 from 55-60 mm , the longer being the males, the shorter the 

 females. The Scandinavian Chiffchaff has been recorded from 

 Orkney and Shetland, the Outer Hebrides, and the Isle of May. 

 On migration the habits of this Chiffchaff seem in no way to 

 differ from those of the Common Chiffchaff, Another Chiff- 

 chaff which is a regular autumn visitor to Shetland, and 

 has also occurred in Orkney and at the Isle of May, is the 

 Siberian Chiffchaff {Phylloscopus collybita tristis). This 

 form breeds in the extreme east of Europe and in Siberia, 

 and although usually occurring only on autumn passage 

 has been found wintering in Orkney and Shetland, and 

 has once appeared at Fair Isle in spring. It differs from 

 the Common Chiffchaff in the absence of yellow in the 

 plumage, in being whiter below, greyer on the back, and 

 in having coal-black legs ; the superciliary stripe is cream- 

 coloured instead of yellow. The bend of the wing and 

 under wing-coverts are sulphur-yellow, less greenish-yellow 



53 O 



