HOODED MERGANSER (continued) 
Age Determination 
Immature birds are similar in gross aspect to adult females but 
immature tertials are straight and frayed at the tip and often appear 
brownish. The middle and greater coverts usually are frayed and brown, 
particularly over the tertials. These feathers are smooth and unfrayed 
on adults. 
A few immatures can be identified as males by the presence of one 
or more light-gray middle coverts emerging among the darker feathers. 
However, it does not appear that the sex of most immatures can be 
determined. 
KEY TO HOODED MERGANSER 
1, Middle Coverts: 
Gay) Mostly pale quay <6 - ashen ses Serene sa nn Adult Male 
(b) Mostly brownish’black or brownish gray ----------------- 2 
2, Middle Coverts: (continued) 
(a) One or more pale gray feathers emerging 
through surrounding dark coverts e-----r rset nnn nnn ennH- Immature Male 
(b) All coverts approximately the same dark 
COLOY ---- n-ne nnn enn enn nn ene nn eens r serra 3 
3. Middle Coverts: (continued) 
(a) Very rough and much frayed ---------------------------- Immature 
(b) Not noticeably rough or frayed ------------------------ 4 
4. Tertials: 
(a) Straight, brownish except center longitudinal 
stripe, much frayed to a long point ------------------- Immature 
(b) Shiny black except for center longitudinal 
white stripe, drooping tips, unfrayed, long 
narrow taper to blunt point --------------------------- 5 
41 
