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Possible and probable
Glaucous x Herring Gull hybrids
Larus hyperboreus x argentatus

Every winter a few paler Herring Gull-like birds turn up along the Norwegian coast. Compared to normal-looking Hering Gulls they share a series of common features; paler primaries, paler tail band, more barred tertials, less black along the feather shaft in the scapulars, less "angry" face due to fainter facial mask and often paler base to the bill. All these features point towars some influence from Glaucous Gull genes. Some will argue that these are only pale extremes of the variation within the argentatus subspecies of Herring Gull. We argue that this kind of phenotypic variation result from introgression of Glaucous Gull genes, at present or in the past, along the northern parts of the Herring Gull range or the southern parts of the Glaucous Gull range. With limited Glaucous- input because of a lower frequency of mixed pairings than for instance in Iceland, the majority of hybrids are expected to be more similar to Herring- than Glaucous Gull.

1st CYJun 2004Vest-AgderNorwayChicks
1st CYNov 2001RogalandNorway4 images
1st CYDec 2002Sør-TrøndelagNorway2 images
1st CYDec 1999Vest-AgderNorway2 images
2nd CYJan 1999HordalandNorway5 images; in-hand
2nd CYJan 1999HordalandNorway4 images
2nd CYJan 2002HordalandNorway6 images
2nd CYJan 2003HordalandNorway3 images
2nd CYJan 2007Vest-AgderNorway3 images
2nd CYFeb 2000HordalandNorway2 images
2nd CYFeb 2000HordalandNorway
2nd CYFeb 2000HordalandNorway2 images
2nd CYFeb 2001RogalandNorway
2nd CYFeb 2003HordalandNorway9 images
2nd CYFeb 2004OsloNorway2 images
2nd CYMar 2000Vest-AgderNorway4 images
2nd CYMar 2003RogalandNorway3 images
2nd CYMar 2004Sør-TrøndelagNorway2 images
2nd CYMar 2006HordalandNorway3 images
2nd CYApril 2005HordalandNorway4 images
2nd CYMay 2002NordlandNorway3 images
2nd CYMay 2002Vest-AgderNorway
3rd CYJan 2004HordalandNorway5 images
3rd CYFeb 2004RogalandNorway1 image
4+ CYJan 2007Vest-AgderNorway4 images

Aberrantly dark Herring Gulls
(Larus argentatus ssp.)

Dark Scandinavian Herring Gulls may represent pitfalls when trying to identify the North-American subspecies smithsonianus. The variation in our argentatus include some darker extremes superficially similar to smithsonianus. Many claims might be smithsonianus, but only individuals showing a full set of classic smithsonianus features ought to be accepted as such. The birds below share some features with smithsonianus, but are all thought to be within the argentatus range of variation.

2nd CYJan 2000Sør-TrøndelagNorwayDark tailed; 6 img.
2nd CYJan 2002HordalandNorway5 images
2nd CYAug 2000HordalandNorway12 images
3rd CYJan 2004ØstfoldNorway8 images

Partial albino or leucistic gulls

The birds presented below are all aberrantly colored gulls. Leucists, albinos and partial albinos.

Adult Black-headed GullJun 2002ØstfoldNorwayLeucist
First winter Mew GullSep 1984BergenNorwayLeucist
First winter Mew GullOct 2003BergenNorwayLeucist
Adult summer Mew GullApr 1999TromsNorwayPart. alb.
First winter Herring GullJan 2003Vest-AgderNorwayLeucist

The Trondheim mystery Gull

This dark-eyed large gull has triggered off many interesting thoughts on the birds identification and origin. The general American point of view is California Gull, while others believe it is a kind of Caspian Gull or a hybrid involving Caspian.

California, Caspian, Herring, hybrid?? Check out the Trondheim mystery! 21 January 2006
In addition to having the same strange jizz as earlier, some characters are still slightly puzzling for this probable 6th. winter bird: The primary coverts on both wings have extensive blacks pigments. Dark iris. P4 does show a distinct subterminal black spot on the outer web. The orbital ring is red, and it is completely lacking head-markings. Four pictures are uploaded here.

16 November 2004
The debated mystery gull from last winter returned at the same site today. Several people from both sides of the Atlantic thought it could be a California Gull ssp. albertaensis. Some features, such as the wing proportions (see flightshots from February) probably exclude California Gull alone, but the discussion still goes on... Have a look at four new pictures here.

12 February 2004
Eight flighshots of the mystery gull in Trondheim is uploaded today. See them here.

9 February 2004
A striking subadult large gull was photographed in Trondheim, middle Norway on February 4th. Have a look at this dark eyed oddity here.