HOW TO MEASURE A BIRD. 



Wing. — Distance from carpal joint C (bend of wing) to the tip of the longest pri- 

 mary D. See cut on page 7. 



Length. — Distance in a straight line from the end of the bill to the tip of the longest 

 tail feather. (Occasionally the middle feathers are much elongated, as 

 in the Old Squaw and Pintail Duck, and in other families of birds, such 

 as Phaethon and Stercorarius. In such cases it is well to give the length 

 from bill to longest tail feather, and also to end of outer tail feather.) 



Tail. — Distance from the tip of the longest tail feather to its base (the point where 

 it enters the body). 



Bill. — The distance in a straight line from where the bill (upper mandible) joins the 

 skin of the forehead (A) to the tip (B). (There are a few exceptions to 

 this rule, in other families, such as birds with frontal plate, etc. Some 

 curved bills are measured along the curve of the culmen, and at times 

 it is advisable to measure from the nostril to the tip of the bill, but in 

 such cases it should always be so stated.) 



Tarsus. — Distance in front of the leg from what appears to be the knee joint (end of 

 tibia) to the root of the middle toe. All measurements are given in inches 

 and fractions of an inch. 



Birds vary so much in size that the length of any one specimen cannot be 

 accepted as a standard for others of the same species. The length measure is, nev- 

 ertheless, of value to enable us to form an approximate idea of the size of the bird. 

 The length of the wing is much less variable, and is an important aid to the identifi- 

 cation of certain species. 



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