xii HOW TO USE THE GUIDE 



known bird, lie will find the number of that bird in the 

 alphabetical index and begin near that point. 



Selecting a conspicuous feature of the bird, he should 

 run through the appropriate column of the Guide until he 

 finds a description to correspond. He should then see 

 whether the descriptions in the other columns agree with 

 his other observations, and continue this process until the 

 identification is complete. 



In other words, the first part of the search is made 

 vertically through the columns and the second part 

 horizontally. 



N.B. The column " Distinctive Features'* should 

 always be consulted. It will prevent erroneous identi- 

 fication, and often, in cases of doubt, suggest the right 

 bird. 



NOTE ON BIRD SIZES 



Familiarity with the following list of four common 

 birds will assist the observer in the habit of estimating 

 sizes at sight : 



Bird. Approximate length.' No. in guide. 



House Sparrow . 6 inches . . 42 



Starling . . 8J .. 90 



Partridge . . 12f .. 126 



Rook . . . 18 ..169 



As the measurement of size is taken in one dimension 

 only, that of length, any exceptional length of tail, bill, 

 or neck obviously makes a bird look smaller than its 

 real size, and it will thus be found later in the Guide 

 than the apparent size would suggest. A study of the 

 following instances will be useful. 



