T HE numbers and names used in this book are those adoDted by the American 
Ornithologists’ Union, and are known both in this country and abroad. The 
lengths given are averages; our small birds often vary considerably and may 
be found either slightly larger or smaller than those quoted. 
On some of the pages a number of sub-species are mentioned. Sub-species often 
cause confusion, because they are usually very similar to the original; they can best 
be identified by the locality in which they are found. 
The nests and eggs are described, as they often lead to the identity of a bird. 
We would suggest that you neatly, and with ink, make a cross against the name of 
each bird that you see in your locality, and also that you write at the top of the 
page the date of the arrival and departure of each bird as you note it; these dates 
vary so much in different localities that we have not attempted to give them. As 
many will not wish to soil their books we would suggest that they have a leather- 
covered copy for the library and a cloth one for pocket use. 
6 
