When it. is realized that no less than 475 species, and 
sub-species, of British birds are now recognized, it will be 
apparent that it would be impossible to do more than briefly 
epitomize the commoner species, and some of these, like the 
robin and the wren, need no interpreter. 
The aim of this chapter is primarily to give, as far as 
possible, the salient features of our commoner native birds, 
as seen during flight. But some species merely “ flit,’ from 
one place to another, and that so rapidly that no details of 
coloration can be distinguished. They can only be examined 
at favourable, and often fleeting moments, when at rest, and 
clear of foliage. Only such as are frequently encountered 
are included here. To attempt more would be to lead to 
confusion. Enough, it is hoped, will be said to help the 
beginner. Experience will soon lead to an ever-increasing 
proficiency — and with this will come an ever-increasing 
conviction that the identification of birds, during flight, is an 
extremely difficult task. Whoever essays it should, whenever 
possible, supplement his efforts by the aid of a pair of good 
field-glasses. These, indeed, are indispensable. 
The small perching birds are, perhaps, the most difficult 
to name at sight, and this because their flight presents so 
little to distinguish one species from another. All fly with 
rapid wing-beats, alternating with a period during which 
the wings are practically closed, causing the body to travel 
209 
