MIGRATION OF BIRDS 7 



is only for general convenience ; many species are 

 represented in more than one group. 



1. Permanent Residents : birds which remain 

 in Britain all the year round. These are com- 

 paratively few in number, and largely consist of 

 insular races of birds which perform regular and 

 often long migration journeys in other parts of 

 their range. Most, if not all, perform short migra- 

 tions, in some cases only seasonal changes of altitude, 

 spending summer on the hills and winter in the 

 lowlands ; examples, the red grouse and dipper. 

 Others, like .the tits and creepers are nomadic and 

 more or less gregarious in the colder months. Few 

 appear to remain in the same locality at all seasons, 

 but possibly some of our British robins and song 

 thrushes, both sub-species of migratory Continental 

 forms, may be non-migratory. 



2. Summer Residents : birds which nest in our 

 islands, leaving in autumn for countries to the 

 south, and return in spring. In addition to the 

 regular summer visitors, which all leave in autumn, 

 this group includes a number of wagtails, pipits, 

 finches and other birds which are represented in 

 winter in our islands by a proportion which remain. 



3. Winter Residents : birds which nest to the 

 north or east of our islands and arrive in Britain 

 in autumn, leaving in spring for their breeding area. 

 With birds like the fieldfare, brambling and jack 



