Just a couple of comments. I am generalising from waders in general, but
assume it will apply to Wandering Tattlers.
First year birds can show a great deal of variation in their 1st
Alternate ("Breeding") plumage. These are the birds you would expect to
be present in Australia in winter. The variation comes about mainly
because the hormonal state of the bird when it moults could be like that
of an adult or an immature. If it has reached hormonal adult-hood
early, it might come into plumage which looks exactly like an adult, and
it might even migrate and breed just as if it was an adult.
On the other hand, if it is still a youngster hormonally when it
undergoes its first preAlternate moult (in the Australian Autumn) it
will bring in plumage which looks like a bird in Basic ("Non-Breeding")
plumage. The effect of this is that it might not change its appearance
at all when it undertakes the same moult which would bring in the
"Breeding" plumage in an adult, or in a bird which is more advanced
hormonally.
It could also happen that a bird will effectively change hormonal states
during this moult, in which case the new Alternate feathers replaced
early in the moult will look like Basic feathers, and the feathers
replaced later in the moult will look like Alternate feathers.
So a bird in Australia in winter which looks as if it is in
"Non-Breeding" plumage could be:
1) a bird which never bothered to moult into "Breeding" plumage.
2) a bird which is actually in "Breeding" plumage.
And also, a bird which appears to be partially in "Breeding" plumage
could be:
1) a bird which is currently in moult
2) a bird which is in "Breeding" plumage only some of which looks like
adult "Breeding" plumage.
These complexities are some of the reasons why the terms "Breeding" and
"Non-Breeding" are confusing and tend to obscure what is really going on.
If the above isn't confusing enough, there is another complexity which
can really help you see what is going on. The way to interpret the
situations mentioned above is to look at the relative amounts of wear
and fading of the feathers, which can often reveal how old they are.
This is often possible from good photos.
So in practical terms, how could you tell if a Wandering Tattler seen in
early September is a bird which over-wintered in the southern hemisphere
or a bird which has returned from the northern hemisphere breeding
grounds? The big clue is to look at how worn is the plumage. Although
there are a number of other scenarios which can affect this (eg a bird
may have done a partial migration, or returned very early due to failed
breeding), in general there is a clear distinction in the degree of wear
between returned adults and overwintered immatures.
The immature birds (in 1st Alternate plumage) will still look fresh.
Think of what the adults look like before they migrate in May. The grey
parts of the plumage will be really grey with neat edges often slightly
fringed paler, and the underparts will show both black and white bars in
profusion.
A returned adult will be in worn plumage, because it's flown around the
planet and probably had a rough time getting abraded at its nest and has
had to deal with feeding babies etc. It has also most likely been
exposed to much longer periods of sunlight, which degrades the feathers,
though the effect of this is less certain, because the UV will be
stronger on birds overwintering in the subtropics, even though for much
less of the day. But such returned adults will look browner above, the
tips of the feathers tatty, and much of the white in the barring below
will have worn off, so the underparts can even look largely solid black.
Despite all the variables, if you know what to look for, the difference
between a fresh immature and a worn returned adult is actually pretty
obvious!
Cheers, Chris.
On 10/05/2012 12:39 PM, Steve McBride wrote:
Hi Greg,
The attached photo was taken at Flat Rock, Ballina on 30/5/2010. Looks like full
breeding plumage to me. The bird disappeared for a few weeks, (no Tattlers seen for
4 weeks), then presumably the same bird (looked the same) reappeared at Flat Rock
on 29/6/2010. Was it the same bird, did it attempt migration & then abort, who
knows? It was then seen regularly at Flat Rock (but not every visit), for next few
months. From memory, not sure, but I don't think it lost the breeding plumage until
Sept/Oct, or perhaps even later?
This year (Winter 2012), we had 2 over-winter Wandering Tattlers (seen regularly at
Flat Rock), both in non-breeding plumage. On 8/9/2012 a third Wandering Tattler
appeared at Flat Rock in what looked like full breeding plumage. On that day there
was lots of calling & chasing between the 3 Wandering Tattlers. The new arrival
seemed to upset the other 2 birds.
Make of that whatever you like.
Cheers,
Steve McBride
Ballina
-----Original Message-----
From:
On Behalf Of Robert Inglis
Sent: Friday, 5 October 2012 4:49 PM
To: Greg Roberts;
Subject: Re: [Birding-Aus] Wandering Tattler time is approaching
Fair enough, Greg. I didn't bother to personally check out the Sunshine Coast
for overwintering Wandering Tattlers this year as there seemed to be plenty of
other people doing that and seeing them.
Wandering Tattlers are interesting birds and quite mysterious. I haven't been
able to find any definite information on the flight paths they take to and from
the breeding grounds in NW North America and E Siberia but it seems that they
must do some island hopping and Hawaii is possibly a major stop-over. There
seems to be little evidence of them using the East Asia-Australasian Flyway to
get here. There are some records of them in Asia but I have recently had
definite evidence that such records need to be treated carefully. I was sent a
photo of a tattler seen in Hong Kong which the 'locals' felt sure was a
Wandering Tattler but it was plainly a juvenile Grey-tailed. That is not to say
all or any of the officially accepted reports from Asia and Japan are wrong, of
course.
If the birds you saw on the Sunshine Coast in August actually did leave for the
breeding grounds last May I wonder if they went all the way or only went part
of the way before turning back? Unfortunately we will never know the answer to
that sort of question until someone does some detailed study on their flight
paths -- perhaps with goelocators. .
I must say that I am surprised to see two Wandering Tattlers still in what
amounts to full breeding plumage in late August; the birds I have seen at that
time of the year have only ever had the slightest vestige of breeding plumage
remaining. Perhaps the birds I saw were all 1st/2nd year birds which did not
attain full breeding plumage anyway and 'your' birds were/are older adults.
Certainly, none of the birds I have seen and which I have assumed were birds
returning from the breeding grounds from late October and onwards had anything
more than a few chevrons on the flanks and under-tail.
So, I've learnt something and that is always good.
I do suspect, though, that the main body of returnees has still to arrive here.
Bob Inglis
Sandstone Point
Qld
From: Greg Roberts
Sent: Friday, October 05, 2012 7:03 AM
To: ;
Subject: Wandering Tattler time is approaching
Bob
The birds pictured in the blog post appeared to be in full breeding plumage.
Also, the one or two tattlers that overwintered at Alexandra Headland were in
non-breeding plumage.
I found in the past on North Stradbroke Island that the time the tattlers
returned could vary substantially from year to year.
Greg Roberts
Wandering Tattler time is approaching
from [Robert Inglis]
[Permanent Link][Original]
To:
"Birding-Aus" < >
Subject:
Wandering Tattler time is approaching
From:
"Robert Inglis" < >
Date:
Thu, 4 Oct 2012 15:57:04 +1000
Greg,Are you sure they aren't just birds overwintering? Wandering tattlers do
overwinter on the Sunshine Coast most years and some even achieve a fair degree
of breeding plumage.My experience has been that the first new arrivals are
juveniles and they arrive around the end of October.It would be a quick
turnaround for birds that leave Australia in May to be back here in August. Bob
Inglis
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