
WOOD DUCK (continued) 
3. Greater and Middle Coverts: 
(a) 
(b) 
Greater coverts tend to show iridescence chiefly on outer 
webs, black margin tends to be wider at center giving 
coverts a slightly pointed look, blue coloring usually does 
not extend onto the third row of coverts anterior to the 
secondaries, and is much restricted distally to coverts near 
the tertials, middle coverts rough, rather small, and some- 
what trapezoidal -----~+------------------------------------ Immature 
Greater coverts tend to show iridescence on both inner and 
outer webs, black margin is generally uniform, blue coloring 
usually extends onto three or more rows of coverts anterior 
to the secondaries, and usually covers most of these feathers, 
middle coverts smooth, large and rounded -------------------- 4 
4. Most Proximal Greater Covert: 
(a) 
(b) 
Usually noticeably greener and duller than more distal 
feathers; tends to be small, narrow, and somewhat 
trapezoidal -------- nnn nnn erent ere ene enn een ne Immature 
Usually slightly lighter purple to greenish; but 
large, wide, and "squarish" -------------------------------- Adult 
SEPARATION OF REDHEADS AND CANVASBACKS 
Adult male canvasbacks have such a great amount of white on the 
upper surface of the wing that they cannot be easily confused with 
any other redhead or canvasback. The secondaries of all other 
canvasbacks are much darker than those of all redheads. 
Thus, the contrast between the dark secondary coverts and the 
secondaries is much greater on the wings of redheads of all age and 
sex groups than on the wings of adult female or immature canvasbacks 
of either sex. This difference is sufficient to separate the two 
Species accurately. 
26 
