1st cycle Larus cachinnans

[JanJ]

Simrishamn 27.7 2012. Caspian Gull with notched tertials. Question is if this is somewhat accetpable for cachinnans or a sign of argentatus influence? I had some trouble reading the ring...

JanJ

[Klaas van Dijk]

This gull bears a metal ring of the Polish Ringing Centre (Gdansk Poland). It might even be possible to identify the last two numbers (upper row) of the ring number?

I have no idea about the species. Larus Poliscka?

[lou bertalan]

hi jan,

slight notches like in this bird are found in some ind. of romanian population also. this bird however has pretty strong triangular patterns on inner GC and thus appears like a mixture of micha and cachi. still could be a pure cachinnans. one of the recently photogr. juveniles in the large murighiol colony (romania) had similarly contrasting and regular patterned inner GC. it would have been nice to see the spread tail...

best wishes,

lou

[JanJ]

HI Lou.

Unfortunately I didn´t see the underwing. However, the notched tertials is a warning signal, although I´ve seen a few - what seemed quite bog standard cachinnans with a more or less similar pattern. Also fairly dark inner webs on the inner primaries should not present a huge problem. Structure when standing was as good as any cachinnans. Further study was done as close as at one and a half meter!
The tail pattern was seen quite good, however, I didn´t obtain images of it though. Similar to the one depicted below, incl. the outer rect by Thomas!

Cheers

JanJ

[lou bertalan]

well, we might have to live with these cachinnans with a inner primary pattern like michahellis (rel. dark inner webs) and in addition, like in the discussed simrishamn bird, a very micha like smudge around eyes...
however, it will remain speculation if these slight variations are due to argentatus genes or even micha in polish populations, or are just within pure cach variation...
with a tail pattern like in the bird in your previous post i'd really call it a "normal" caspian gull though.

lou

[JanJ]

A few comments where made on Facebook (a swedish birding site there), by Ronald Klein - who suggested argentatus genes as a propability due to tertial pattern. Ruud saw a possible michahellis and so on. The metalring seems to be a polish one, hard to read, however, one might be able to sort a few numbers out....

Jan

[lou bertalan]

another bird photogr. by lars on 21.7. with a gdansk ring in tommarp. it also has slight notches in tertial fringe and a more or less homogenous dark underside - to me an even better candidate for cach x tatus, maybe second generation:
http://www.artportalen.se/artportalen/g ... 420239.JPG
http://www.artportalen.se/artportalen/g ... 420237.JPG
http://www.artportalen.se/artportalen/g ... 420238.JPG

(i know you have seen these pics, jan, but i wanted to put them in this context anyhow)

lou

[JanJ]

The very same Lou, confirmed by plumage detailes and ring nr. Taken by Hans on 21.7 (6 days prior to mine). As he puts it "no direct argentatus feel"
Another one of the same bird - taken on 19.7 labeled as a LBBG here - http://www.artportalen.se/birds/gallery ... eID=415085

JanJ

[JanJ]

Hans Larsson kindly provided ringingdata for the above gull, since he also photgraphed the same one. Thanks to Gregorz Neubauer for providing Hans with the data!

http://www.artportalen.se/birds/gallery ... eID=420239

JanJ

[lou bertalan]

ok, anything is possible in polish paradise

talking about tertial pattern: see this one, also with a polish ring:

http://www.tarsiger.com/images/hytpe/la ... 6P1325.JPG

http://www.tarsiger.com/images/hytpe/la ... 6P1347.JPG

lou