redhead 
    assume a complete eclipse plumage. Seven-year old captive/drakes molted

    directly from (the old to the new mk breeding plumage without an* eclipse,

    but       drakes yearlings, two-year-olds and three-year-oldsý
showed 
    a complete change of plumage in the post-nuptial molt. In eclipse these

    young drakes wore a solid brown plumage similar in many respects to the

 
    plumage of the hen. 
           In all brightly colored river ducks drakes, the eclipse plumage
is 
    always an entirely new dress. I have never seen a drake Mblting directly

    from the old to the new msllbpmw breeding plumage without an eclipse,
nor 
 
    have I seen a partial eclipse plumage in which many of the feathers of
the 
    breeding plumage are retained. In the blue-winged and green-wAnged teal,

    the eclipse plumage closely resembles the plumage of the hen; lmuskm

    adult drakes and hens are difficult to distinguish when the males are
in 
    eclipse. In the Mallardgadwallshoveller and pintail the ecplise plumage

    (more closely 'resembles the plumage of the ia young drake in juvenal
plumage 
4 vthan it does the plumage of the hen, 
            Post-nuptial changes do not concern the plumage alone. In the
mallard 
    the bright yellow bill of the mahm breeding male becomes drab olive green

    in summer; the blue-gray bill of the redhead male becomes dull grayhmb
and 
    the conspicuous light crossline of the bill almost disappears. In the

    canvasback the brilliant vermillion eye becomes flecked with yellow and

 
    brown pigment. 
           In captive-reared birds in the Delta pensmated drakes mmaembbam
ak 
   begin the post-nuptial molt shortly after the first copulations. Thus

   Ward observed that wild mallard and pintail drakes confined in the Delta

 
   latchery and induced to breed abnormally early by exposing them to daily-

 
   increasing artificial light, began their post-nuptial molt at the time
of 
 
   the first copulations in January. These drakes(were in)their eclipse plumage

   during late winter and spring, nearly halra year ahead of the normal eclipse