Stuart,
To answer your query regarding whether waders have two moults in a year,
going from breeding into non-breeding and vice versa - YES (see below). I am
not a wader expert so I am not sure that all species of wader have both
plumages and thus moult twice a year.
The following relates to birds in general, rather than waders specifically.
For species that have a breeding (alternate) and a non-breeding (basic)
plumage they go through two moults per annual cycle. However, not all
feathers are moulted in both moults. One of the moults (the prealternate
moult - meaning it is the moult into the alternate plumage) is a partial
moult in most species of bird where all feathers except the main tail and
wing feathers are typically replaced. The other moult (the prebasic moult)
is a complete moult meaning that all feathers are typically replaced.
So the sequence of plumages starting with the juvenile plumage (the first
"set" of feathers - i.e not down) for a typical bird with two plumages a
year is as follows:
Juvenile Plumage ---- first prebasic moult (partial in most species) ---
first basic plumage ---- first prealternate moult --- first alternate
plumage --- second prebasic moult --- second basic plumage --- second
prealternate moult --- second alternate plumage etc etc until the definitive
basic and definitive alternatie plumages are attained (definitive plumages
are those that remain relatively unchanged from year to year i.e. adult
plumage. The moult into the definitive plumage is called the definitive
basic or definitive alternate moult). This terminology is only one of the
terminologies used - it is called the Humphrey and Parkes Terminology.
You will notice I have said typically a couple of times. This is because
moult can vary quite a bit, for some birds they may "skip" replacing a few
feathers in one moult, so for example a stint may carry a few of its first
primaries (e.g. if it skipped say the outer two in its first complete moult)
and also have some of its second primaries (say primaries 5 to 8) and is
growing its new third primaries (say primaries 1 to 4). That is this bird
has feathers of three different ages in the one wing!!. To take another
example with waders, moult of the primaries usually starts from the inner
primary and progresses outward, I have seen a stint that had replaced the
first few primaries, did not moult the middle primaries and was growing the
outer primaries.
For those birds which have only a single plumage each year the sequence of
moults and plumages is the same as above if you omit all alternate plumages
and prealternate moults.
Hope this answers your question!
Cheers, Dean
From: "Stuart Fairbairn" <>
To: <>
Subject: [BIRDING-AUS] Moulting waders.
Date: Mon, 1 Jul 2002 17:24:12 +1000
Do waders have two moults in a year, going from non breeding into breeding
and then the reverse to return to non breeding?
Stuart Fairbairn
Sydney Australia
Birding-Aus is on the Web at
www.shc.melb.catholic.edu.au/home/birding/index.html
To unsubscribe from this mailing list, send the message
"unsubscribe birding-aus" (no quotes, no Subject line)
to
_________________________________________________________________
Join the world?s largest e-mail service with MSN Hotmail.
http://www.hotmail.com
Birding-Aus is on the Web at
www.shc.melb.catholic.edu.au/home/birding/index.html
To unsubscribe from this mailing list, send the message
"unsubscribe birding-aus" (no quotes, no Subject line)
to
|
