Vlll BIRDS OF EASTERN NORTH AMERICA. 



HOW TO MEASURE A BIRD. 



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

 primary D. See cut on page 8. 



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 elong- 

 ated, 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 excep- 

 tions 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 ao 

 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. 



