i897. THE MIGRATION OF BRITISH BIRDS. 247 



stations, forming a nearly complete circuit of the British Isles, with 

 outliers in the most important directions, that constituted the essential 

 feature of this exceptionally valuable series of observations, and the 

 recorders again and again acknowledge the cheerful and intelligent 

 co-operation of the light-keepers, without whose aid the plan could 

 not have been carried out. Thus a record has been obtained such as 

 has never before been attempted in this or any other country, the 

 special character of which, to use the words of the " Digest," " can 

 only be fully appreciated when it is realised that, in order to study the 

 phenomena of bird-migration in the British Islands, it is necessary 

 that the data upon which any deductions may be satisfactorily or 

 safely founded should be based upon observations taken synchron- 

 ously at stations encircling the entire coast." This cardinal and all- 

 important condition has been now for the first time fulfilled. 



The migratory movements appear to be exceedingly complex and 

 subject to many influences, but it was found (i)'that our shores form 

 an accustomed highway and resting-place eminently favourable in 

 situation and directly in the course of the legions of migratory birds 

 which annually make a double journey between their northern 

 summer and their southern winter quarters ; these we may term 

 " Birds of Passage." (2) " Our islands have a vast bird population of 

 their own, and the majority of these birds belong to purely migratory 

 species. Some of them are ' Summer Visitors ' from the southern 

 regions, or ' Winter Visitors ' from continental Europe, Iceland, &c." 

 (3) There are many birds sedentary in our islands, but migratory 

 within these limits ; these may be termed " Partial Migrants." (4) 

 Mainly owing to our variable climate there are frequent " Migrations 

 within the British area itself, and intermigration with the islands off 

 our western coasts, especially with Ireland. These occur during the 

 winter months, and hence they will be alluded to as ' Winter 

 Movements.' " Often, owing to a combination of meteorological 

 conditions, more than one of these movements may be observed in 

 progress simultaneously. 



Two main routes are found to be taken by the birds during 

 migration : those species which spend the summer in Northern 

 Europe pass along our east coast, taking their departure at some 

 point or points between the north coast of Norfolk and the Shetland 

 Islands, proceeding in a north-easterly direction, and returning by the 

 reverse route in the autumn ; those birds which visit us from Western 

 Europe arrive in spring on our south-easterly coast, landing between 

 the Wash and the Kentish shore, and return in autumn the same way; 

 this latter is known as the East and West route. There are no essentially 

 northern birds recorded in these latter flights, the species being 

 suggestive of Central Europe, or of countries lying even still more to 

 the eastward. The birds landing on the southern section of England 

 spread either northward, up the east coast, or pass to the west along 

 our southern shores ; and it is pointed out that occasionally these 



