Hi Janet, et al.

One issue is that various systems exist for plumage and molt 
terminology, so definitions can depend on what system you are dealing 
with. The system in most widespread usage is the Humphrey-Parkes 
(H-P) system, developed in 1959, so you probably want to use it for 
your baseline.

Here's a good succinct web site reference on the H-P system, with 
definitions ...

         http://www.scricciolo.com/Plumages%20and%20Molts/plumages_molts.htm

If you're really a gulton, here's all you (n)ever wanted to know 
about some of the issues with H-P and alternative systems, especially 
for gulls ...

         http://elibrary.unm.edu/sora/wb/v31n01/p0050-p0056.pdf

Hope this helps ...

Phil


At 17:51 04/28/2008, Janet Millenson wrote:
>Based on its plumage, the Red-shouldered Hawk that's been hunting in our
>yard lately isn't an adult; presumably it fledged in 2007. So how should I
>describe this bird -- "juvenile"? "immature"? maybe even "subadult"?
>Different references seem to use different terms for the same thing.
>
>Can anyone explain the precise meaning of these terms, and how they apply to
>various families of birds? Thanks.

==================================
Phil Davis      Davidsonville, Maryland     USA
                 mailto:[log in to unmask]
==================================