Sep 25, 2012

Our Lesser black-backed gulls move southwards

Unfortunately we do not have picture of JA6V but JA5V was ringed next to it.
Yesterday (24th of September) Paul Veron reports that one of our Lesser black-backed Gull (Larus fuscus) pullus was seen in Guernsey. This is our first reading for a gull in the Channel Islands and very nice that is was a LBBG pullus where the colony of birth is known. The colony where it was ringed is a semi-urban colony at Ågotnes which is a large supply base for the oil industry in the North Sea. The person responsible for the security kindly gave us access to the whole base and on 12th of July the urban ringing team in Bergen (Christian Pedersen, Vegard Finset Fjeldheim and Arild Breistøl) with help of Bent Fjeldheim from Hallingdal ringing group (blog is in Norwegian) entered the area. We ringed 18 Lesser Black-backed (one of these with metal ring only) and 34 Herring Gull pullus this day. As the other colonies we visited this summer the production of Lesser black-backed was not to good, but the Herring gull production was what we think is a normal level. Since this was our first visit to the colony we do not know the production numbers exactly so the production estimates are uncertain. We also have another reading of a LBBG from this colony but this one have so far only moved to the city center park in Bergen.

JJ1V was ringed in the semi-urban colony at Ågotnes 12th of July and seen for the first time in the city center of Bergen 5th of September. The 20th of September it was still present.

Since the Ågotnes colony is close to Bergen and reading with telescope don't seem to affect to birds much we visited the colony four times after ringing. Of the 17 LBBG pullus we ringed with colour rings 11 individuals (64 percent) has survived to fledging which is quite good. The observation in Guernsey was another confirmation of that the few LBBG pullus that fledged actually have survived.

Readings of Lesser black-backed gull pullus ringed in the colony at Ågotnes. JA6V has been seen 1309 kilometres south west in Guernsey and JJ1V in the city centre of Bergen.

A later post will summarise the colony at Fedje island which is a natural mixed colony of Herrings and LBBGs.

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