Some Yellow-legged Gulls, Romania, August 2009

[Cristian Mihai]

Pics taken on August 2009. Location: Vadu, the Black Sea coast, Romania.

[marsmuusse]

Hi Cristian,

When looking at these 2cy micha's, I easily can construct a question from some Finnish friends, looking at argentatus at the dump of Tampere.
Would it not be nice to set up a research on how to distinguish between michahellis 2cy and argentatus 2cy in the period May-October.

[Cristian Mihai]

Hi marsmuusse,

Obviously I can help with observations regarding 2cy michahellis, but I'm not in the position to complete the work here, because argentatus is a rare vagrant for Romania (as a matter of fact, I've never seen one here...)

[marsmuusse]

Hi Cristian,

Sorry for being not clear enough. You don't have to to do the complete work, in fact you only have to do half of it!

Just as a rough idea:

Main question: What are the phenotypic differences between argentatus (S Finland) and michahellis (Romania) in 2cy birds between April - November.
Subquestions:
1. Timing of complete moult.
2. Extent of post-juvenile moult in initial group (April-May) regarding tertials and wing-coverts.
3. Pattern of 2nd gen feathers in scapulars.
4. Pattern in 3rd gen feathers in scapulars.
5. Pattern in new wing coverts.
6. Tail pattern (juvenile) in initial group (April - May).
7. Tail pattern in last group (November).
8. Window in inner primaries in initial group (April - May).
9. Window in inner primaries in last group (November).
10. Development of pigmentation in bare parts.
etc, etc.

Method:
Argentatus is observed in 2 weekds intervals, starting 1 April, last at 30 November in Tampere (Finland). Sample size is 50 birds). Sample is random, ringed birds most appreciated.
Michahellis research likewise in Bucharest (Romania).

Definitions:
1. Juvenile feathers: ....
2. 2nd gen feathers: .....
3. 3rd gen feathers: .....
4. Regarding patterns:
4a. juvenile pattern = .....
4b. 2nd gen barred pattern = .....
4c. 2nd gen anchor pattern = .....
4d. 2nd gen shaft streak pattern = .....
4e. 3rd gen pattern = ......
5. Regarding bare parts:
5a. Black = .....
5b. Brownish = .....
5c. Flesh coloured = ....
5d. Yellowish = ....

Maybe something like this. Of course it should be worked out in details.
Remember we have to be very consequent in our definitions, to make field research at two locations comparable. But once you both agree on the definitions, you can start doing the research. You just print a few sheets and score at your local patch. You combine findings later on and agree on who has to work it out in co-operation.
Hopefully there will be some conclusions possible on population level, and maybe a set of characteristics may even be diagnostic on individual level.
Last years, we have done quite some research on 2cy and 1cy michahellis in W Europe. Theo, Ruud and I can dig up the methods we have used, so maybe we can make it 'a 3 location research', including findings of W European birds as well.
For Finland, Markku and Hannu are probably the first to think about, and they already have a large set of photographs.

Remember this kind of research can be very very time consuming when you exactly want to score feather details in the field!

5.

[lou bertalan]

hi

P8224745m surely is a 2cy caspian gull. it has small p10 mirrors.

lou

[Theo Muusse]

Of course, but the p10 mirror in 2cy birds is not diagnostic.
I lost a mystery quiz by naming a 2cy mich with mirrors on p10 a cach...

Theo

[lou bertalan]

Of course, but the p10 mirror in 2cy birds is not diagnostic.
I lost a mystery quiz by naming a 2cy mich with mirrors on p10 a cach...

Theo

too bad - that you lost the quiz and that there is hardly any 'diagnostic' single feature in our large gulls - yes i have seen birds like maybe this with only a hint of a mirror: http://k53.pbase.com/o2/01/753501/1/106 ... copypb.jpg
if you have a pic of a 2cy mich with larger p10 mirror, could you please post it here?
have you seen this caspian with juvenile primaries that have a tiny white p10 "mirror": http://ic2.pbase.com/o3/09/645509/1/107 ... G_0416.jpg

all the best,

lou

[Theo Muusse]

I will ask Ies to post the picture.
Theo

[Ies Meulmeester]

I will ask Ies to post the picture.
Theo

See attached picture and note the mirror on p10 in the left wing!! Attached picture is from the same one as this: http://www.iesmeulmeester.nl/fotos.php? ... catsub=227

[lou bertalan]

I will ask Ies to post the picture.
Theo

See attached picture and note the mirror on p10 in the left wing!! Attached picture is from the same one as this: http://www.iesmeulmeester.nl/fotos.php? ... catsub=227

bedankt ies! and theo.

this is slightly horrifying and a nice pitfall for a quiz. but i'd think it is really rare. like dark eyes in adult michas. pure speculation but possibly such birds develope larger mirrors than average as adults? (e.g. caspian like p9 mirrors and all white p10 tip).

is there any study that shows development of mirrors in ringed argentatus (which to a certain amount can show a mirror in 2nd gen. p10, i think mostly in eastern baltic birds)?

lou