Page 2 of 2

Re: Some Yellow-legged Gulls, Romania, August 2009

Posted: Mon Dec 07, 2009 7:34 pm
by Ies Meulmeester
Theo Muusse wrote: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
http://www.birdforum.net/showpost.php?p ... count=1128
Check the asymmetrical pattern of the mirrors on p10 in both wings of the 2cy Yellow-legged Gull in the link above. Note especially the pattern of p10 in the left wing, it seems that the large mirror merge with white at the underside of the inner-web of p10. I have never seen a 2cy with such large mirror/pattern on p10 as on this one!

Ies

Re: Some Yellow-legged Gulls, Romania, August 2009

Posted: Mon Dec 07, 2009 8:38 pm
by Cristian Mihai
Yep, I spotted this gull today, December 7th in a park in Bucharest. Here is another shot with the same bird in the background. Sorry for the quality, but the light was really poor.

Re: Some Yellow-legged Gulls, Romania, August 2009

Posted: Mon Dec 07, 2009 8:41 pm
by lou bertalan
p10 underside even better visible in this post (1st pic). together with an advanced 1cy (worth spending a look too): http://www.birdforum.net/showpost.php?p ... count=1129
i struggled to age the bird since there are large mirrors and large tongues. even the whole black portion in left wing is more restricted than in the right wing with longer pale tongues. and it has a "thayeri" pattern as a 2cy!!! lack of white primary tips and solid tail band, bill pattern etc. are in favour of an unusually advanced 2cy though. edit: crossposted with cristian: there you go, this is the image i meant.

Re: Some Yellow-legged Gulls, Romania, August 2009

Posted: Mon Dec 07, 2009 10:41 pm
by adriaens
Not only the pattern of P10 seems to be asymmetrical, but also the moult stage: on the left wing, P10 is still growing.
Perhaps this feather got severely damaged and had to be replaced by a next-generation primary ?
Still an extremely unusual pattern for a Yellow-legged Gull though!

assymetric guy refound

Posted: Tue Jan 05, 2010 11:07 pm
by lou bertalan
one new pic of the weird one, now a 3cy (5.01.10 herastrau park, bucharest, cristian took the pic). his head shape looks weird for me also.

Re: Some Yellow-legged Gulls, Romania, August 2009

Posted: Mon Feb 01, 2010 6:56 pm
by Jonas Landolt
2. Winter Ylg from Zürich, Switzerland with abnormal right P10. The other P10 seems to be normal.
Good Gulling
Jonas

Re: Some Yellow-legged Gulls, Romania, August 2009

Posted: Mon Feb 01, 2010 8:27 pm
by lou bertalan
thanks jonas for this example from a different region! it shows similar irregularities on underside to p10 as well.

i think i found a proof for peter's suggestion that this kind of abnormal p10 has been replaced again after complete moult, either due to accidental loss or due to some hormonal disfunction, at least for the bucharest bird: searching through cristian's pics i found the same guy on 2 pics from 28.09. in these pics it had the weird mirror on right wing but left wing seemed to be normal; when refound in december, left p10 had the very odd "thayeri" pattern with a long white tongue connected to a large mirror - so this left p10 would have to be 3rd gen., maybe right p10 also, considering that roundish mirror. see these 2 posts here:

http://www.birdforum.net/showpost.php?p ... count=1213

http://www.birdforum.net/showpost.php?p ... count=1214 (these pics show it on 28.09.)

cheers,

lou

Assymetrical guy refound again

Posted: Wed Feb 24, 2010 8:07 am
by Cristian Mihai
February 23rd - I spotted again the bird in the same location (Herastrau Park, Village Museum area). Here are some shots.