I got the assignment to contribute something about the status and
distribution of the nominate Lesser Black-backed Gull here in
That is not really possible without discussing the other subspecies,
I base this largely on an article in a Swedish birding magazine from
Vår Fågelvärld vol 70 nr 2:
Warning: it gets messy!
David Erterius: Olika typer av silltrutar i Sverige
(Different types of Lesser Black-backed Gull in Sweden)
I also scanned some pages from a field guide which of course has to
try to make sense of the mess.
Luckily for me almost all the birds in the Stockholm area look like
Larus fuscus fuscus breeds mainly around the Baltic Sea, in
Finland and in the White Sea in northwesternmost Russia.
It is a long distance migrant wintering mainly in tropical eastern
Contrary to the more western populations graellsii and intermedius,
nominate fuscus is declining.
Nominate fuscus is the breeding Lesser Black-backed Gull
along the Swedish east coast (i.e. Sweden's Baltic coast).
It is replaced by intermedius along the Swedish west coast.
Intermedius also breeds along much of Norway's coast and
south via Denmark and northwestern Germany to the Netherlands, where
it meets graellsii.
Graellsii breeds mainly in western Europe from Portugal north
to the Netherlands, in Britain and Iceland. In recent years it has
been expanding its range. There are now sustainable populations on
the Canary Islands and in Greenland. Breeding colonies of Lesser
Black-backed Gull on the Swedish west coast contain more and more
light mantled individuals, some of them as light as birds from the
In the graellsii-intermedius contact zone in the
Netherlands and northwestern Germany intermediate birds, sometimes
called "dutch intergrades", are found. These birds' mantle colors
form a continuum of gray tones between the parental populations.
Presumably birds from this area spread and reach i.a. southern
Sweden. In breeding colonies along the Swedish west coast birds with
all kinds of shades of the mantle color can be found nowadays and
light mantled birds are more and more often observed in the southern
The situation gets even more messy by the fact that Russian heuglini-type
birds regularly reach Finland, which is not far away. Heuglini
breeds in remote areas in Russia which are not normally visited by
birders or banders, so there is no hard evidence in the form of
banded heuglini being found in Finland, but the light
mantled birds regularly observed in Finland look like birds
photographed deep in the breeding area of heuglini in
Russia. Also, in the Netherlands banded intermedius have
been found that they thought looked a lot like the heuglini-type
birds found in Finland, and banded graellsii and intermedius
have reached Finland.
Here come the pages from the field guide, rather big jpgs (around 7
They are from the highly recommended Collins
Bird Guide by Svensson, Mullarney and Zetterström.
Their page on Great and Lesser Black-backed Gulls is here.
An illustration comparing juvenal Lesser Black-backed with juvenal
European and American Herring Gulls is here.
Their general introduction to gulls including an introduction to
age-groups is here.