ANALYTICAL KEYS 
LYNDS JONES, Ph. D. 
HOW FO USE THE KEYS. 
While these keys are made for the purpose of identifying any bird in the hand, they 
are not intended to give more than the barest information about the bird. You should at 
once turn to the description of the bird whose name you have found by means of the keys, 
and read what may be found there before remaining content. Often an unsatisfactory 
identification by the keys will give you the clue so that you can turn to the body of the 
book and there make sure of your bird. ‘The keys, then, are but a means to an end. 
They are merely for rapid determination, not for any other particular information. 
There are three separate keys. First of all, a Key to the Orders; next a Key to the 
Families under each order; and lastly a Key to the Species under each family. You 
should always begin with the Key to the Orders to get your bird in the right group. 
Having found the order to which it belongs turn to the Key to the Families, find the order 
there by the number which precedes it in the Key to the Orders, and determine to what 
family it belongs. In like manner turn to the Key to the Species given under each family 
and there determine the species. The families are numbered in 1, 2, 3, order under each 
order, but the species are given the number which they bear in the body of the book. 
While the orders are not serially arranged in the Key to the Orders, they are arranged 
in I, 2, 3, order in the Key to the Families. Likewise, while the species are not serially 
arranged in the Key to the Species they are so arranged in the body of the book. 
It is important that you should know how to use the keys unless you are already 
familiar with most of the birds described in this book. At first sight they may seem 
confused, but after a little practice in the use of them they will prove very simple. Let 
us suppose that you now have a bird in hand which you wish to identify. Suppose it is 
an American Bittern. In the Key to the Orders, “I.” calls for a bird with webbed or 
lobed feet; your bird has neither webs nor lobes, so you must turn to the contrasting 
character which will be under “II.,’’ which so far describes your bird. Next is “A. Legs 
and neck long and slender.” That is true of your bird. Then the next is “1. Lores 
(region between the eye and bill) bare.” Your bird has bare lores, so it must be one 
of the Herodiones, Order 9. Turn now to Order 9 in the Key to the Families. Here 
the first is “I. Bill straight, sharply pointed.” That is right for your bird. Your bird 
belongs to Family rt, Ardeide. Turn now to the Key to the Species and find Order 9, 
and Family 1 under it. ‘The first here is “I. Length about 45 inches’; but your bird 
measures about 30 inches, so you turn to “III. Length less than 35 inches.” Your bird 
is not pure white (A), but it is (B) “mottled and streaked with rusty and yellowish 
brown,” so you conclude that it is an American Bittern, number 247 in the book. Turn 
to that number (page 622) and verify your conclusion by the minute description there 
given. Any other case would work out on the same principle. 
Unless otherwise specified the length of a bird is the straight distance from the tip 
of its bill to the end of its tail when it is laid upon its back with neck and bill extended. 
The wing measurement is taken from the bend (the carpal joint) of the folded wing to 
the tip of its longest primary. The bill measurement is the stright distance from the 
edge of the feathers at the base of the bill on top to the tip of the upper mandible. This 
distance is also sometimes referred to as the chord of the culmen. ‘The tarsus is meas- 
ured from the heel joint to the angle made by the outer toe. 
(939) 
