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

(last update: 26-10-2014)

Larus fuscus fuscus adult J0X0 2008-2014, Ashdod, Israel. Picture Amir Ben Dov.

J0X0 was ringed at Nordfugløy, Troms, north Norway. Below, you also find a map of Europe, with the ring readings for J0X0.

The most northern island in the county Troms is Nordfugløy. Here you find a Lesser Black-backed Gull colony in cloudberry mires, about 300 meters above sea level. The oldest data about the presence of this colony are from 1963 when 125 pairs were estimated. Still, there was nothing known concerning the subspecies composition before the first adult birds were caught and colour-ringed in 2002. The breeding population varies a lot in numbers between the years, with a minimum of 15-20 pairs in 2002, and with a maximum of 100 pairs in 2006 and 2007. Nowadays, with about 100 pairs, it is the largest colony of Lesser Black-backed Gulls in northern Norway.

The island also hosts a breeding population of 100+ pairs of arctic skuas and 200+ pairs of Common Gulls. There is only one island in this ringing program which is higher up north: Loppa Island, which is a similar colony at about 200 meters above sea level.

The ringing program on Nordfugløy started in 2000, when juveniles were ringed. From 2000 to 2008, 172 juveniles were ringed here. Up to May 2008, 20 of these juveniles were seen outside the breeding range. Between 2002 and 2007, 17 adults were ringed as well, with 7 rediscoveries. This is a remarkable high recovery rate, certainly due to the predominant western migration route chosen by the adults breeding on this island. Pale-mantled birds from Nordfugløy have been rediscovered in Portugal, Spain, Italy and Libya. One dark fuscus-type bird has been observed frequently in Israel.

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.

below: Larus fuscus fuscus 12cy J0X0 April 11 2014, Ashdod, Israel. Picture Amir Ben Dov.

Head clean white by early April.

below: Larus fuscus fuscus 12cy J0X0 February 01 2014, Ashdod, Israel. Picture Amir Ben Dov.

Head densely streaked by early February. Again, late in its moult of P10, like seen in previous years.

below: Larus fuscus fuscus 9cy J0X0 April 08 2011, Ashdod, Israel. Picture Amir Ben Dov.

Within two weeks, head clean white by early April, compare to image from March, below.

below: Larus fuscus fuscus 9cy J0X0 March 25 2011, Ashdod, Israel. Picture Amir Ben Dov.

By late March, still much streaking on the head.

Two images below: in direct comparison to armenicus and heuglini.

below: Larus fuscus fuscus 9cy J0X0 March 12 2011, Ashdod, Israel. Picture Amir Ben Dov.

below: Larus fuscus fuscus 9cy J0X0 February 12 2011, Ashdod, Israel. Picture Amir Ben Dov.

P9/-: P9 fully grown, no old primaries left. Again, small mirror on P10 this year.

below: Larus fuscus fuscus 9cy J0X0 February 04 2011, Ashdod, Israel. Picture Amir Ben Dov.

P8/-: P8 fully grown, no old primaries left.

below: Larus fuscus fuscus 8cy J0X0 December 10 2010, Ashdod, Israel. Picture Amir Ben Dov.

P6/P9: Two outer primaries, P9-P10, still old. Note the minute mirror on P10, still as small as it has been in previous years.

below: Larus fuscus fuscus 8cy J0X0 March 17 2010, Ashdod, Israel. Picture Amir Ben Dov.

Primaries all present, but moult in wing-coverts.

below: Larus fuscus fuscus 7cy J0X0 December 11 2009, Ashdod, Israel. Picture Amir Ben Dov.

P7/P9: Two outer primaries, P9-P10, still old. P7 just longer than P6. Note the minute mirror on P10. Secondary moult started as well, so moult strategy in flight feathers much in line with what would be expected in the complete moult of other taxa in N Europe. It would be interesting to know if the central tail feathers are dropped as well.

Larus fuscus fuscus 7cy J0X0 February 27 2009, Ashdod, Israel. Picture Amir Ben Dov.

Primary moult finished soon, with only P10 to grown a few inches, now ate the length of P8. P8 with a small white tip, P9 lacking a tip and a mirror, but a very small mirror on the growing P10 just visble in the picture.

below: Larus fuscus fuscus 6cy J0X0 February 16 2008, Ashdod, Israel. Picture Amir Ben Dov.

Primary moult almost finished with no old primaries left. P7 fully grown.

below: Larus fuscus fuscus 6cy J0X0 January 09 2008, Ashdod, Israel. Picture Amir Ben Dov.

below: J0X0 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.