INTRODUCTION 
On the wings of the most common species of ducks, there usually 
are slight differences in feather color, pattern, shape, wear, or 
feather replacement, that are sufficient to separate immature (young 
of the year) from older birds. Age determination is largely a matter 
of the step-by-step search for one or more of these characters which 
usually consist of traces of the juvenile plumage. Wings on which no 
traces of immaturity can be found, or in some instances which have 
positive adult characters, are from adult birds. 
This report summarizes the methods used in the Duck Wing Collec- 
tion Survey to determine the age ard sex of the more common species in 
the kill (Glover, Fred A. and J. Donald Smith, 1963, Waterfowl Status 
Report, U.S. Fish and Wildlife Service, Special Scientific Report-- 
Wildlife 75). Keys are provided to assist in an orderly search for 
pertinent characteristics. Plates 1 and 2 illustrate the wing parts 
discussed in the keys and the method of measuring a duck wing. Workers 
will find the keys useful as guides to identification of the various 
sex and age groups of the more common ducks,-. however, before a high 
level of proficiency can be attained, they will need to examine the 
wings from a number of birds of each group in order to become familiar 
with the variations among individual wings within the groups. 
The age and sex criteria being used for the mallard, black duck, 
American widgeon, green-winged teal, pintail, redhead, canvasback, 
greater and lesser scaup, and the common goldeneye are probably reliable 
throughout the period from October lst to at least mid-January. Age 
criteria for the blue-winged teal, cinnamon teal, shoveler, gadwall, 
wood duck, ring-necked duck, and hooded merganser are known to be reli- 
able for the early portion of the season, but accuracy has not been 
thoroughly established for these criteria later in the season. We 
have had very limited opportunity to check the reliability of age 
criteria for the mottled duck, bufflehead, ruddy duck, scoters, eiders, 
oldsquaw, and large mergansers. Further study may result ‘n verifying 
characters useful for distinguishing the age and sex of most of these 
species. At present, methods for these species are largely hypothetical. 
Familiarity with the age and sex criteria found on duck wings is 
of considerable help during banding operations. Ducks caught in traps, 
however, often become water-soaked, dirty, and otherwise quite be- 
draggled, thus making identification by minute differences between 
feathers virtually impossible. For this reason, identification of age 
by wings cannot be substituted for cloacal examination in many cases. 
