DIRECTION OF THE MIGRATION FLIGHT 29 



accountable cause, the concluding stage of the westerly course of 

 the migration. A similar phenomenon is presented by the same 

 bird in England. In that country the Honey Buzzard is met with 

 as a breeding species only in solitary instances, but arrives in 

 tolerably large numbers on the east coast during the autumn 

 migration. Such examples as originate from the northern limits 

 of their breeding zone in Europe and Asia bring their westerly 

 flight to an early close in England, where, then turning south, they 

 pass via Western France and Spain to their winter quarters in 

 Africa. It is hardly probable that more than a few fly across the 

 Bay of Biscay, for, according to Rodd (Birds of Cornwall), these 

 birds are a very rare occurrence in the most western portions of 

 England, including the Scilly Isles. 



Now and again, however, they do appear to take such a course, 

 as, according to Thompson, a pair of these birds has been seen on 

 three different occasions during the summer months in Ireland, one 

 of the birds having been killed in each instance. 



We have already, at the beginning of this chapter, mentioned 

 Richard's Pipit as affording a striking instance of a migration flight 

 from a location far to the east. The bird in question in the course 

 of its autumn migration actually passes over the immense tract of 

 country which lies between the Sea of Ochotzk and the Atlantic 

 coast of Spain. 



In treating of several species migrating in directions from 

 north to solith, and vice versa, the view has been expressed that 

 their migratory flights were confined within a definite number of 

 degrees of latitude further north or further south, relatively to 

 the more northern or more southern situations of their breeding 

 homes. The case of Richard's Pipit, however, proves, beyond 

 question, that such gradations in the range of the migratory 

 flights, measurable by degrees of longitude, do not apply to 

 species whose migratory flights proceed in directions from east to 

 west for the breeding area of the interesting species referred to is 

 strictly and exclusively limited to Datiria Dybowsky having about 

 twenty years ago succeeded in discovering its nests in that district ; 

 while not one of the many travellers of earlier or more recent times 

 who have investigated the ornithology of European and Asiatic 

 Russia has ever met this bird breeding to the west of Lake Baikal. 



Truly astonishing as the migration journey of this small bird, 

 from one end of the Old World to the other, may appear, there can 

 be no doubt of the fact that the individuals observed in Heligoland, 

 Holland, England, France, and Spain, during the autumn migration, 

 originate from far-off Daliria. Nor must such individuals be in 

 any sense regarded as isolated rarities or ' stragglers,' for not only 



