Heuglini in Poland

[michal rycak]

Hi,
today i would like to know your opinions about these gull. I have seen in few days ago at Central Poland in Vistula river.
My experience with heuglini is null so any comments to exclude intermedius are welcome.

Michal

[Ruud Altenburg]

My personal experience from Łubna is that graellsi/intermedius is about as common on migration as fuscus. On one of my last visits I observed a colour-ringed 3cy from France!

To me this looks like an advanced 3cy LBBG but at this age LBBG and Heuglin's of course can be very hard to separate. I would concentrate on 2cy birds, these offer the best ID potential.

Some LBBGs from Łubna:
http://www.xs4all.nl/~daarruud/polen/fuscus.html

ID of 2cy heuglini:
http://www.gull-research.org/heuglini-id/index.html

[michal rycak]

Hi Rudd!
I saw in april about 50 adult LBBG and only 4-5 different 2cy birds. None of them didn't make me suspicious to consider Heuglini. But i will looking strongly for another 2cy bird
I send photos of these bird to Grzegorz Neubauer and he's opinion is strongly pro-heuglini bird. Also Grzegorz forward these photos to Hannu Koskinen
and he's opinion is also pro-heuglini. Personally i can't say anything becous lack of any experience with these species.

[JanJ]

So - what would be the pro-heuglini features in the subject gull, as stated by Koskinen and Neubauer. As they are both members to this forum, it would be interesting to share their views! BTW, is the all white underwing a pro-heuglini feature?

Jan

[Ruud Altenburg]

Hallo Michal

for 2cys (and 3cys) you should have a bit more patience, they normally arrive in bulk next month (in Holland at least). About the ID as heuglini: plumage-wise this is an advanced bird (new tail and secondaries), but occasionally graellsii (Dutch birds) and especially intermedius may look like this. We have written a paper on 3cys in Birding World, see http://gull-research.org/papers/paper.html (5th from top left).

Of course ID is not based on moult alone, so I'm gladly willing to learn from Greg and Hannu.

Cheers

Ruud

[grzegorzneubauer]

Hi All,
no discovery of new features this time just a short discussion and some - also not entirely new - thoughts.
The basic pro-heuglini feature in Michal's LBBG is - without going into details - it's advanced plumage and structure (reminiscent of cachinnans to me, esp. head). Although its clear from Mars et al. 2005 paper that some 3cy intermedius and graellsii are similarly advanced, it is also clear that this is not so frequent - while at the same time it's a rule in heuglini. Completely white underwing - or almost so - also seems to be a rule in 3cy heuglini. A lack of mirror on p10 and pale iris are uninformative (the opposite would be a pro-heu characters).
My personal view that this bird is heuglini is reinforced by date and locality, which are both very appropriate for heuglini to occur. Personally I have seen two nearly indentical 3cy's, both in mid April, like this one. Both they occurred among nominate fuscus, during strongest peaks of their migration in C Poland, like this one. Again, there is no reason for odd, advanced intermedius/graellsii not to occur in C or E Poland in April but immature 2cy and esp. 3 cy's western-type LBBGs (the 'classics' like on plates 1-3 in Mars et al. paper) peak here in late spring/summer, say, May to August (as Ruud wrote), while are extremely rare on earlier dates. Therefore, to me it is far more likely that these pale 3cy's that migrate north with fuscus are heuglinis.
While we cannot be sure, this bird could well be a 3cy heuglini (though as Hannu stated not the easiest type, with p10 mirror, boa-streaked neck and dark eye) and is very similar to some 3cy heuglinis photographed by Hannu in Finland. Also, the Polish bird is quite similar to the one you've discussed some time ago, the 3cy from Chioggia, Italy Apr 2005:
viewtopic.php?f=13&t=229
The conclusion - by Mars - was that it is best labelled heuglini (until we know more...). I don't see any reason for which Polish bird could not be labelled the same.
Btw, perhaps we could share more light on id of such birds by trying to find out how do look 3cy LBBGs in Netherlands/W Europe now, in April? Have they arrived already? Can anybody post few pics? Most/all pics in Mars et al paper are from summer (or autumn). Are 3cys now streaked on their heads/necks? Do they show clear saddle? Can you find similarly advanced birds among 3cy LBBGs?
Best
Greg

[adriaens]

Hi Greg,

check this one, a very advanced graellsii/intermedius, for example:
http://www.gull-research.org/lbbg3cya/3cyjanpic05.htm

More info on http://www.gull-research.org/lbbg3cya/l ... anapr.html.

[grzegorzneubauer]

Hi Peter,
thanks. A very advanced one, indeed, assuming it's western origin...
Btw, I found poor pics of one of my previous 3cys. Perhaps a slightly better candidate, with its more powerful bill and structure, almost white tail with very reduced black (not on the pics), but more importantly, darkish iris and dark spots on the hindneck creating a (weak) 'boa'. On the flight shot, it is cut in half just about the 2cy argentatus.
Occurred with a flock of nominate fuscus (one Finnish-ringed) and two other pale-mantled adults. 12 Apr 04, Torun, central Poland.
Greetings,
Greg

[grzegorzneubauer]

should be: above the 2cy argentatus
G

[Ruud Altenburg]

A supporting character (but not more than that) may be the 'freshness' of the primaries. Those 2kj heuglini leaving Europe with juvenile outer primaries (highly unlikely in western birds) may still have jet black feathers when returning to Europe in their second summer. Second generation primaries in most advanced western birds are worn and have turned brown. Further indication would be a mirror on p10 in such 'fresh' primaries. However, in this case the ageing will be a problem (how to exclude 4cys)...

I had hoped to do a quick unrepresentative sample in Amsterdam yesterday but the number of gulls in the city was terribly low. One decent group of 78 LBBGs, which included (only) two 2cy and three 3cys. All were 'classic' western birds (one example attached). I've asked Roland-Jan for an image of one of his ringed birds from Gambia to show that some Dutch birds are very advanced. To be continued...