Kelp Gull in the portuguese coast

After the fabulous photographs of an adult kelp gull Larus dominicanus taken in Vila do Conde, by Inocêncio Oliveira in the last days http://birdsofportugal.blogspot.pt/search/label/Gaivota-dominicana a fellow birder (Pedro Ramalho) shared some photos of a second odd ind. seen last month in Peniche. Their ID is not always straitforward, specially if you are not expecting that a kelp gull could be roaming our coast.

GBBG, probable hybrids and putative kelp gulls, all have been seen at Khnifiss lagoon in Morocco, and the mistery around these big black gulls is far from being solved, however these sub-adult ind. seems to share more traits with Larus dominicanus ssp. vetula than with Larus marinus or Larus michahellis hybrids. The long legs seem to have the characteristic greenish tinge, the trailing edge of the secondaries is massive even when at rest, the eyes are very dark with yellowish orbital ring ( pers. com. by the observer), the bill has a very bulbous tip, and in most shots the mirror on P10 does not merge to the tip.



Note also the upperpart tone...

 The question is, what are they doing in portuguese coast? Assited journey on a fishing trawler that returned from north african coast, just riding along with the wintering LBBG and GBBG, or are mixed genes from the later giving them the northern latitude directions.

http://go-south.org/03_Birdlist/lardom_&_larmar.pdf
http://gull-research.org/gbbg/5cyjune.HTML
http://www.birdforum.net/showthread.php?t=181282

1st record for continental Europe in Paris 1995 - photos
http://www.talk.gull-research.org/viewtopic.php?f=13&t=929