102 STUDIES IN lURD-MIGRATION 



or Arctic races of the following species : — Mealy Redpoll 

 (several forms), Bullfinch, Crossbill, Creeper, Goldcrest, 

 Willow - Warbler, Chiff- Chaff, Redbreast, Wheatear, 

 Song - Thrush, Dipper, Great Spotted Woodpecker, 

 Barn-Owl, etc. 



Such is a broad general outline, based on many- 

 years devoted to their investigation, of the geographical 

 distribution of birds during their various migratory 

 movements in the British area. It must be left to local 

 observers to fill in the detJiils — they alone have the 

 opportunities for acquiring the necessary special know- 

 ledge. 



