xc INTRODUCTION 



Read down this as before, when, by throwing out the families to 

 which it does not belong, you come to Ardeidm — 2'. Bill straight 

 and sharp, neck and most of head' feathered, to which it does belong. 

 Go now to the page specified (72), and run down the Key to Genera, 

 contained in Family Ardeidse, and you find that it belongs to the 

 genus Ardea, to which you are referred (p. 74). Here you find the 

 general characters of the genus and a key to its species. As you 

 know the bird is bluish gray and its size large you find it to be Ardea 

 herodias, of which a detailed description is given (p. 75). If you 

 have been identifying a bird that you have shot, you will have your 

 own fresh measurements to compare with those in the description 

 (see page xxvii.). 



In some of the more obscure birds you will find on getting to the 

 description of the species that you have made a mistake in running- 

 down the keys, but by patience and care in following them you will 

 be able to identify all but the most difficult birds. 



After a little study you will grasp the general classification of 

 birds so that it will not be necessary to go through the whole series 

 of keys for each bird. You may not know what it is, but you 

 know many things that it is not, and if you make a practice of 

 eliminating you will narrow down the possibilities so that it will be 

 much easier to find your bird. You may not know whether it 

 is a crow or a raven, but you do know that it is not a water bird, 

 a hawk, owl, or sparrow, and so you can go on throwing out what 

 you know it is not until you have to look up only those about which 

 you feel uncertain. 



The question as to which subspecies a bird belongs to, unless de- 

 terminable by geographic range, can often be decided only by expert 

 ornithologists with large series of skins for comparison, and, in such 

 cases, found often among some of the flycatchers, the song spar- 

 rows, and wrens, the only way to be sure of your bird is to send it 

 to a museum for identification. The National Museum in Washing- 

 ton and the American Museum of Natural History in New York will 

 both identify material sent them. 



