
With the exception of the mallard (Carney, Samuel M. and 
Aelred D. Geis, Mallard Age and Sex Determination from Wings. 
J. Wildl. Mgmt., 24(4):372-381), we have been unable to measure 
the degree of accuracy of the various age and sex determinations 
to our complete satisfaction, therefore, we have not previously 
released these keys to other workers. The demand for all of the 
keys has been so persistent that, although we are in the process 
of preparing an illustrated version, it seems most practicable to 
distribute this report on existing methods. In doing so, we 
solicit the comments and criticisms of our readers. 
MALLARD 
Sex Determination 
Wings with vermiculated scapulars are from males. Wings with 
non-vermiculated scapulars may be from either males or females. 
The white bar anterior to the speculum extends at least partially 
over the tertials on wings from females, but terminates at the 
proximal edge of the speculum on male wings. 
Age Determination of Males 
The juvenile tertials are often frayed and faded, usually 
narrow, and lack the pearly color of adult tertials. By late 
November these are replaced by first winter tertials, identical 
in appearance to adult feathers. Juvenile tertial coverts are often 
frayed, faded, and narrow. These may be replaced by first winter 
coverts which are broader, unfrayed and similar to adult coverts. 
Many immature males show light edging on the inner webs of the 4 
most distal primary coverts. Adults do not show this character.. 
The middle coverts of immatures are narrower and more trapezoidal 
than those of adults. Occasionly, these feathers are rough and/or 
lightly edged on immature birds. This is not true of adults. 
Age Determination of Females 
Tertials that are frayed or faded are remnants of juvenile 
plumage and are found only on immature birds. The tertial coverts 
of immatures are often frayed, faded and narrow, and the 2 most 
proximal often lack the white of the anterior speculum bar. 
Conspicuous light edging on the inner webs of the 4 most distal 
primary coverts is found only on immatures. Adults may show 
"minute" or no.edging on these coverts. Middle coverts of imma- 
tures are narrow and trapezoidal, while adults are broadly rounded. 
