Posted by
NewMexiKen on
URL: http://bald-eagles-of-broward-county-florida.17.s1.nabble.com/Immature-eagle-molting-pattern-tp3090482p3097274.html
Thank you, Carolyn--
To clarify, the odd word "juvenal" refers only to the plumage of a
"juvenile" bird. "The juvenile eagle is in juvenal plumage." There are
several overlapping sets of nomenclature for the various plumage stages.
Eagles start out with natal down, which then is replaced (by a
pre-juvenal molt) with juvenal plumage of the fledgling. Then there are
annual molts into a series of second, third and fourth or fifth "basic"
plumages, the final one of which is the adult basic plumage. Then the
basic plumage is replaced each year thereafter.
If a bird has a flight feather plucked, it will replace it quite quickly
during any stage, outside of the molting cycle.
Some songbirds such as warbler and tanagers have a spring (pre-nuptial)
molt into a bright breeding plumage (called the "alternate" plumage,
since it is worn only rather briefly) that is replaced in late summer or
fall by their basic plumage.
Interestingly, unlike the eagles' orderly and gradual replacement of
wing feathers, some birds such as many species of ducks and geese may
lose all their flight feathers at once and are rendered flightless for a
few weeks after breeding.
Ken
Ken and Mary Lou Schneider
Miramar, Florida and North Aurora, Illinois
Rosy Finch Web Site: <
http://www.rosyfinch.com>
Ken's Blog: <
http://blog.rosyfinch.com>
Ken's Photos: <
http://flickr.com/photos/rosyfinch>
Carolyn J (via Nabble) - No Reply wrote: