Sunday, 18 November 2012

Baltic gull or Baltic origin!?

Another great gull however unringed, this time from Espinho   41° 0'8.67"N  8°38'49.00"W, the jizz is obviously slender, with long primary projection, probably the 150% more as stated for nominate fuscus, exceding tarsus lenght. At distance the strinking dark jet black upperparts, equalling primary color stood out in the middle of the other LBBG present.

Here (above) together with some dark late moulting graellsii/intermedius.

Note the dark upperparts, and very  long primary projection.

Leg color and dark smudge on bill could suggest a 4cy.

Outer primaries old but still in good condition, and showing a small P10 mirror, winter head sreaking restricted to the hindneck  and behind the eye.

P5 new, P6 on the way, dropped P7 and P8 to P10 old, moulted outermost secondaries???  dropped outermost GC and growing outermost MC....I would say primary moult was suspended on P4 still at breeding site, then started moulting again in the wintering grounds, some of the November fuscus seen at Israel showed similar moult score . Western Europe is not on the migration route taken by nominate fuscus unlike graellsii/intermedius, however several ringed birds have been seen on a regular basis in Spain, 1 or 2 color ring readings from Portugal and Morocco.
However nominate fuscus is diclining, estimated 90% since 1970, with 18 000 - 19 000 pairs worldwide (2006),  pesticide ingestion in African wintering quarters are one of the causes with high mortality rate between immature birds due to liver failure, and recent expansion northwards of pale-mantled intermedius into all dark fuscus breeding colonies.

No comments: