Hi Tweets,

Martin Muller writes, re Humphrey-Parkes molt-sequence terminology:

>I would not have added the remark about the bird spending most of its time
>in Basic plumage. Just look at the Mallard here in the Pacific Northwest, it
>is in Definitive Alternate/breeding plumage from roughly October - July
>(look at them out there, in their eclipse/non-breeding/Definitive Basic
>plumage right now). Similarly, the Pied-billed Grebe changes into Basic
>plumage sometime in October-December (some later) and will be back in
>Alternate as early as January or March at the latest.

You're right, Martin, I shouldn't have added that remark as an unmodifed
assertion, but it was late. Many species within the same genus or family
have different molt-calendars. Consider the Northern Shoveler Anas clypeata:
the typical male is in Basic ('eclipse') plumage for almost three-quarters
of the year, hereabouts molting to Alternate in Mar-Apr, then fading back
into Basic in mid- to late summer Jul-Aug.

>This is the only part
>of the otherwise crystal-clear system I find confusing,

I wonder if the underlying and incorrect assumption is that many
non-passerine species have molt-calendars no different to those of most
passerines, because that's what. In my own mind, I have to consciously avoid
using warblers, for example, as a molting Greenwich Mean Time, because those
songbirds were the first things I learned when I started birding, and even
now I unconsciously relate to that standard sometimes.

Another potential source of confusion is relating molt-calendars to the
human one. The birds may not be finished their sequence in a neat 365 days.

>and (I'm only human)
>this confusion led to my initial resistance to adopting the system. Not
>anymore, though. Perhaps it is better to refer to Basic plumage as the
>plumage a bird molts into (shortly) after breeding. That helped me out
>(still has its shortcomings).

Maybe it would help to separate them in your mind to note that
territorial/breeding-display/breeding is the duty and Alternate plumage is
the uniform --since all of the individuals wearing the Def Alt plumages in a
species/subspecies look the same, one could equally easily call it a uniform
as a plumage-- it wears doing so. Come to that, that leads to a
perhaps-useful analogy: it might help to think of the Def Alt male (or
female in those species where they assume territorial acquisition and
display duties) as being in uniform because they're on breeding duty, and
out-of-uniform, its Basic plumage, the rest of the time when it's off-duty
(in migration, wintering). The juvs look different because kids usually want
to look different from their parents, anyway. '-)

Michael Price A brave world, Sir,
Vancouver BC Canada full of religion, knavery, and change;
mprice at mindlink.net we shall shortly see better days.
Aphra Behn (1640-1689)