have more than one song and more than one call note, and different 
birds render them differently. 
The American Ornithologists’ Union check list number precedes the 
scientificname. Use it instead of the index when consulting Chap- 
man’s Manual. When naming a new bird, locate it in its family; 
then look for conspicuous points, wing bars, etc., and often by de- 
ciding what it is not, you will follow down to the correct clue. If 
it is an immature bird or a female, it will be more difficult to 
identify. 
Conspicuous markings are printed in italics. The measurements 
given are approximate only. Remember that a song sparrow is 
six inches long, about the size of an. English sparrow, and that a 
robin is ten inches long. 
