Glaucous Gull - Grote Burgemeester

Glaucous Gull

Grote Burgemeester

Larus hyperboreus

Pictures: Teus Luijendijk

27th March 2004, Katwijk aan Zee ZH

21st April 2005, Katwijk aan Zee ZH

27th March 2004, Katwijk aan Zee ZH

Glaucous Gull Larus hyperboreus is known to hybridize often with Herring Gulls L. argentatus. Nobody, however, knows exactly what the resulting hybrids will look like. On the other hand, there is general consensus that gulls that show intermediate characters between the two species, are in fact such hybrids.
This bird was discovered in Katwijk aan Zee ZH, a place where often large gulls are resting and preening their feathers. Not only was it conspicuously larger than surrounding Herring Gulls, it was also much paler. The plumage recalled even that of a first-winter Glaucous-winged Gull L. glaucescens, but this option was quickly ruled out because of the faint but still noticeable dark terminal tail band. The primary pattern was very interesting, a sort of greyish buff with white fringes on every feather. The bill showed a little bright pink and the feet were also quite bright pale pink.




Glaucous Gull hybrid - hybride Grote Burgemeester Larus hyperboreus X argentatus first winter; videograbs (320x). Katwijk aan Zee ZH, The Netherlands, 27th March 2004.

21st April 2005, Katwijk aan Zee ZH

This bird was also discovered in Katwijk aan Zee ZH. Its untidy plumage, the pale iris and the lack of markings on the secondaries indicate that it's a 3rd calendar year bird.



Glaucous Gull - Grote Burgemeester Larus hyperboreus second winter; digital pictures (approx. 65x). Katwijk aan Zee ZH, The Netherlands, 21st April 2005.