338 THE BIRDS OF HELIGOLAND 



feathers and end pointedly below ; by their sides a second series of 

 fine streaks run m the line of the shafts down to the lower third 

 of the feathers. 



The measurements of this example are as follows : — Total 

 length, 6-89 ins. (175 mm.); length of wmg, 3-32 ins. (85 mm.); 

 length of tail, 3-19 ins. (81 vim.) ; length of tail uncovered by wings, 

 1-96 in. (50 mm.). The nail of the posterior toe is -47 in. (12 mvi.) 

 long. 



The breeding stations of this species extend fi-om the Petchora 

 eastwards to the Pacific Ocean. A''on Middendorff found it nesting 

 at the Boganida up to 71° N. latitude. 



149. — Blue-headed Wagtail [Plaukopfige Bachstelze]. 

 MOTACILLA FLAVA, Limi. 



Heligolandish : Blii-hoaded GiiUhlnhhex = Blue-headed Wagtail. 



Giihlblabber is the Heligolandish name for the genus of this and 



the next two species of Wagtails, and signifies something very 



yellow. 

 Motacilla Jlava. Naumann, iii. 839. 



Blue-headed Wagtail. Dresser, iii. 261. 



Bergeronnetle printanicre. Temminck, Manuel, i. 260, iii. 181, iv. 622. 



This pretty little bird is numerously distributed as a breeding 

 species not only from the most western parts of Europe to the most 

 eastern parts of Asia, but also across the Pacific Ocean from the west 

 coast of America to the Rocky Mountains. As one might expect, it 

 also visits Heligoland in very large numbers during both migration 

 periods — though naturally its numbers are mcomparably larger in 

 autumn than in spring ; but even durmg the latter season, if the 

 weather is tolerably favourable, flocks of hundreds may be seen 

 covering the sheep pastures. 



This bird is of rare occurrence in England as well as in 

 southern Norway ; in southern Sweden as far north as Stockholm, 

 it is, however, a fairly common breeding species. Accordingly, 

 the innumerable quantities which touch on Heligoland during 

 the autumn migration cannot originate from regions more or less 

 to the north of the island, but nmst get to Heligoland by an 

 east-to-west route, differing in this respect from their congeners 

 which have been treated of hitherto. 



