Lesser Black-backed Gull at Broome tip

To: Nikolas Haass <>
Subject: Lesser Black-backed Gull at Broome tip
From: Harry Nyström <>
Date: Tue, 22 Jan 2013 15:28:50 +0200

Here are the first comments from Finland after my rough translation. The
comments are provided by Mr. Visa Rauste, who has studied gulls for several
years (decades?) and has been on the national rarities committee for almost
20 years of which 11 as the chairman (until 2011, when he left the seat).
Another person is also quoted, and the person is clearly stated. I will
still try to forward the photos to some other laridists for further review,
but to my knowledge the comments by Mr. Rauste are practically as competent
as can be.

I'll keep you posted if other comments emerge.

Visa's comments:

*"First of all, the identification is very dependent on the accuracy of the
white balance and correctness of the exposure of the images. If we go with
the assumption that they are correct, the bird is definitely not a "normal
heuglini". The upperparts of a heuglini should never be that dark and they
should show a clearer bluish tinge. On the other hand, it should be noted
that the line between a heuglini and a fuscus is not as clear as sometimes
is suggested. And because of that, there has not been much support in
Europe and especially in Finland to draw a line between these two taxons to
split them into two different species.

*When it comes to the structure of the bird, it is to my opinion fuscus
enough, but the structural difference between a fuscus and a heuglini is so
small and more or less on the average that I wouldn't give it much weight
when identifying an individual as a distant rarity on the other side of the

*The moult is also better in line with fuscus, although I don't have my own
data collected of wintering birds. The interruption of the moult in the
primaries at this time of the year in that way is not typical for either
taxons but is the "personal solution" of the individual that is probably
related to the otherwise extraordinary life phases of the bird.

*A little disturbing feature comes to my mind regarding the photos: the
iris of the bird is untypically dark for a fuscus, which almost always
(especially during Summer) has a clear light yeallow iris. The iris should
not show any or only slight spotting, when this individual shows it quite a
*I also have to say that I don't know anything about the gulls of the
southern hemisphere, but I have to rely that the locals can identify and
exclude them."*


Visa's comments after having a good night's sleep in between when asked
about the possibility of an intermedius:

*"Yesterday I wasn't keen on trying to open the whole Lesser Black-backed
Gull -dilemma, and I'm still not. But I'll open it just a little, anyway.
The difference between an intermedius and a fuscus is a "line drawn in
water" when examined on an individual level, although they are different
enough as populations to deserve their subspecies status.

In other words, a "dark intermedius" is identical to a "light fuscus". And
I literally mean "IS identical", not "looks identical". ;-)

*Of course, an individual that is lighter than a typical fuscus and darker
than a graellsii (or heuglini) can be called an intermedius. Note that such
a bird might still be from the phasing region of fuscus and heuglini and
not from the phasing region of fuscus and graellsii, which would be the
"genuine" intermedius. Of course, even in Finland we have all kinds of
LBBGs, for example like this - what would you call this:

*Having said that, I still got the feeling yesterday that the individual is
more "dark as a fuscus" than "dark as a typical intermedius". This concerns
of course only the impression on the darkness (which is affected by many
things, starting from the display one uses when viewing the photos). The
darkness cannot be estimated accurately enough from photos, not even as
good as these. If the bird was captured, one could use the Kodak-scale to
assess the darkness of it; a typical graellsii is about 9-11, intermedius
11-13 and fuscus 13-17.

*But now all I can give is a "no can do", in addition to throwing out some
impressions. Nevertheless: I have no reason to think this individual is a
heuglini. No reason at all.

*But... Something still doesn't add up.

*The bird e.g. looks a bit long-legged, but it may not be essential.

*What could be essential is the pattern of the innermost primaries: if I am
calculating the primaries correctly (differentiating the outermost
secondary and the innermost primary is not as straightforward as one would
think), this bird has black patterns only in the 6 outermost primaries (P4
might have a very small dot on the edge of the outer web, but can be seen
only in some very close photos).

*Finnish birders, Antero Lindholm and Annika Forsten, have studied the wing
tip patterns on Baltic Gulls (LBBG fuscus) of a known age, and in a data
consisting of 138 +3cy individuals only 1 (one) bird had black in just the
6 outermost primaries:

*All in all, this individual seems to have so many "minor faults" that I
would like to familiarize myself with the arguments that state this cannot
be a dominicanus. Unfortunately I won't have the time to do this in the
next few days."*


Some other comments have also been given, this one from Petri Lampila, also
a member of the national rarities committee:
*"In addition to the minor faults already stated, the individual seems to
lack all winter plumage features (streaking on the head). One would expect
such winter plumage features from a northern hemisphere gull. I don't have
experience from the fuscus in winter plumage, but for example the heuglinis,
which I just recently saw in Goa (ca. 50 individuals), were all very
clearly in their winter plumage. Of course there are exceptions to the rule,
but the list of untypical features is starting to be a little long for a

Additionally, the possibility of a hybrid should be taken into
consideration somehow - at least according to some.


2013/1/22 Nikolas Haass <>

> Hi Mike,
> No, this is not an incredible way to argue because it wasn't intended to
> be an experiment using the Broome gull as a 'control'. I was just wondering
> if the NW India birds, in turn, can be used as a valid 'control' for the
> Broome bird. There has been a long discussion about these birds in India
> and apparently it still has not been resolved which taxa winter in NW
> India. So, yes, the Indian birds could be heuglini OR taimyrensis.
> To the Broome bird: It still doesn't look like a perfect L. f. fuscus to
> me for the reasons I discussed in previous mails. I know that some people
> favour L. f. fuscus, but to my knowledge a number of people besides me have
> made the case for L. f./h. heuglini, too. I agree that the bird is too dark
> for taimyrensis, which I suggested based on iris colour and bill shape. I
> am interested in the identification of this bird and contributed to it to
> my best knowledge.
> BTW in case the bird will be proven to be a L. f. fuscus, I won't be
> embarrassed at all.
> Nikolas
> ----------------
> Nikolas Haass
> Sydney, NSW
> ________________________________
>  From: Mike Carter <>
> To: Nikolas Haass <>; Tony Palliser <>;
> Cc: 'George Swann of Kimberley Birdwatching' <
> >; 'Rohan Clarke' <
> >; 'Danny Rogers' <>;
> 'Tony Palliser' <>; 'Jim Allen' <>
> Sent: Tuesday, January 22, 2013 9:59 PM
> Subject: Re: [Birding-Aus] Lesser Black-backed Gull at Broome tip
> Nikolas, what an incredible way to argue? It
> seems that you are saying that because you say that the Broome bird
> is heuglini that is what it is and any evidence leading to a
> contrary conclusion must be false. Surely the logical conclusion is that
> the Indian birds are paler than the Broome bird because they are heuglini
> as
> would be expected at that site whereas the Broome bird is fuscus as the
> colour and other factors suggest.
> Mike Carter
> 30 Canadian Bay Road
> Mount Eliza  VIC
> 3930
> Tel  (03) 9787 7136

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