nominate Lesser Black-backed Gull (L. f. fuscus)

(last update: 30-12-2009)

Larus fuscus fuscus J916 April 2007 Israel & February 2008 Egypt. Pictures: Amir Ben Dov & Knut Olsen.

J916 was ringed at Froholmen as juvenile in 2006. Below, you also find a map of Europe, with the ring readings for J916.

The ringing program at Froholman started in 2005 and within three years (2005-2007) 8 adults were caught on the nest. The catches of juveniles were better, with 162 juveniles colour ringed in the period 2005-2008; although last year only 2 birds were caught. 2008 has been a dramatic year regarding juveniles in all north Norwegian populations. None of the adults have been rediscovered outside the breeding range, up to May 2008, but three juveniles were seen again.

One of these birds is shown here as well, J916. This bird was seen in Israel and one year later in Egypt, nicely demonstrating the migration route already known for nominate fuscus from Finland. When J916 turned up in Egypt in February 2008 as 3cy bird, the upper-part grey tone was very dark, supporting the idea this is an offspring of pure fuscus.

More information about migration strategies in Norwegian fuscus and the ringing programme in the three northern counties of Norway: Nordland, Troms and Finnmark, can be found here: The summary for juveniles can be found in the fuscus 1cy October section, the summary for adults can be found in the fuscus adult October section.
Morten Helberg, Geir Systad, Ingve Birkeland, Nils Lorentzen & Jan Bustnes published an article about this research in Ardea 97, 2009, titled: Migration patterns of adult and juvenile Lesser Black-backed Gulls Larus fuscus from northern Norway. The complete PDF can be found HERE.

above: 2cy J916 April 05 2007, Ashdod, Israel. Picture: Amir Ben Dov.

Hard to describe the exact moult stage of this 2cy bird in spring. What can be seen of the scapulars and wing-coverts, it certainly looks like a retarded bird, with plenty juvenile feathers in the wing-coverts. The median coverts are recently replaced, with new feathers showing obvious internal markings, not like the plain dark feathers (with accentuated shaft streak) often found in 2cy nominate fuscus. Also, obvious anchor patterns on the 2nd generation scapulars. In general, very alike 2cy spring birds from western Lesser Black-backed Gull populations, although nothing can be said about primaries and secondaries.

below: 3cy J916 February 19 2008, Za `Farãna, Egypt. Picture: Knut Olsen.

Original picture was pretty dark, levels (for complete image) have been pushed up in Photoshop, to get some contrasts. So please be careful interpreting the grey tone of the upper-parts. P5 is just visible underneath the longest tertial, with obvious white tip. Outer primaries look relatively dark (new), and the blunt tip of the wing in a certain way suggests the outermost primaries are still not fully grown: which would suggest two simultaneous moult waves (Staffelmauser), a well-known moult phenomenum in nominate fuscus. However, there seems to be a dark spot in the mud, right behind the primary tips, making firm statements about the moult stage difficult unfortunately.

below: J127, Ring readings. Picture: Morten Helberg.

The ringing research is described in fuscus adult March section and fuscus adult October section. All resights up to May 2008 are included in this research, in the three northern counties of Norway. Colonies could either consist of pure fuscus birds, or colonies could show mixed breeding birds, both pale-mantled birds and fuscus types. Adults were trapped during the incubation period in late June, using walk-in cages. In mixed colonies with pale and dark-mantled birds, sub-species were determined easily in the hand. 199 birds were caught: 172 fuscus, 22 pale-mantled birds and just 5 birds undetermined.
Between 2000-2007, 16 birds (8%) were resighted. 10 pale-mantled birds (10/22 = 45%) and only 6 fuscus (6/172= 3,5%) were seen outside the colonies. When considering only mixed colonies, the figures don't change much; resighting probablities for fuscus remain low.
Several birds confirmed the idea of fuscus being an eastern migrant: single observations from central inland Norway, the Baltic Sea and Israel demonstrate the eastern migration route (eastern flyway through Finland, Black Sea, Israel to the Rift Valley into the African Great Lakes). However, there were observations of fuscus in England, and later that winter this bird turned up in Morocco and another bird in Portugal.
Pale-mantled birds were found in England, 3 on the Iberian Peninsula, and single birds in Morocco, Belgium, Italy and Libya. These represent the western migrants.