2nd or 3rd-cycle cach ?

[adriaens]

Bit of a weird looking bird, seen at Blankenberge (Belgium) today. I find it difficult to decide upon its age, but a retarded 3rd-cycle would be my guess.
Photos are not great because the bird was feeding far off at sea.

[lou bertalan]

hi peter,

this one is a bird very similar to yours: http://lou.bertalan.de/gulls/pic/hi/up_0431.jpg and http://lou.bertalan.de/gulls/pic/hi/up_0122.jpg in terms of brown parts distribution and rectrices. i struggled to age it but decided it has to be a 3rd cycle, especially by 3rd gen. looking tail band and inner primaries with wide white tips. and it has a longish p10 mirror. i have never seen a 3rd cycle with such a small p10 mirror(!) like yours and thus immediately reacted: this is a 2cy. some 2cy indeed can show pretty pale greyish inner primaries like e.g. this: http://lou.bertalan.de/gulls/pic/hi/up_0114.jpg - but note black reaching p3 and no clear white tips contrasting to the grey (and typical 2nd gen. rectrices). so, in the end i think you're right with 3rd cycle even though it has an incredibly small p10 mirror since most caspians at this age look like this! : http://lou.bertalan.de/gulls/pic/hi/up_0415.jpg

http://www.netfugl.dk/pictures/birds_us ... 7013_3.jpg this 2nd cycle has pale 4 inner primaries with seemingly white tips! and a pale iris.

all the best,

lou

[Theo Muusse]

Peter's bird looks like a 3cy to me too.

Theo

[Theo Muusse]

0431 looks a 3cy too, 0415 may also be a 4cy ...

Theo

[JanJ]

I agree with the suggestion 3cy. Ageing gulls often a good guess.
The only feature that immediately stands out as somewhat peculiar in Peters cachinnans being a 3cy - is the small mirror, as been said here. However, I would put more trust in the inner primary pattern - with their clean looking grey pattern with broad white tips. Tail pattern would be another clue. We are used to age cachinnans with a small mirror on p10 as 2cy, provided of course that other plumage features doesn´t stand out as to advanced for the given age. The variability stand out quite well when you look at varies 2 & 3cy, some 3cy have adult like secondaries, some not (while 2cy always have, and some with no visible mirror on the second gen. p10), large mirror on p10 and a smaller one on p9:

http://www.iesmeulmeester.nl/fotos.php? ... catsub=224

http://www.iesmeulmeester.nl/fotos.php? ... catsub=387

Note the brownish hue on the inner prmaries (significant or not):

http://waarneming.nl/foto/view/249854

Jan

[adriaens]

Thanks for the interesting replies.
Apart from the small mirror on P10, the smooth brown pattern on hindneck and breast also struck me as unusual for 3c Caspian Gull.

[pim wolf]

apart from those smudgy marks on it's neck and the lack of mirrors on p9 and p10 it looks a lot like this 3cy photographed at Westkapelle on 13 November 2009.

regards, pim