It continues to be grey and virtually birdless – surely the
least exciting bird winter in Oslo in the nearly 25 years I have lived here.
An appointment down town this morning allowed me to check
out what urban birds there might be around the Opera. I failed to find the
Peregrines on their normal perch on the Posten building so any excitement was
going to be on the gull front which as regular readers know is not a family of
birds that I normally find that exciting but rather frustrating. In addition me
looking at gulls is a sign of complete desperation!
There was a large gang of mostly 1st winter
Herring Gulls hanging around waiting to be fed. This autumn there has been a lot
of social media focus on weak Guillemots on the fjord which has resulted in a campaign
to feed them with fish and especially by the Opera where many Guillemots wait
offshore to be fed. This source of easy food has of course been discovered by
the smart and opportunistic local Herring Gulls and this has now resulted in
them being fed on an industrial scale away from the Guillemots so as to allow
the Guillemots to feed successfully and in peace. Personally, I am no fan of
this artificial feeding as the young gulls are missing out on how to discover
their own food (it was quite striking how relatively few adults birds were
there) and there is plenty of natural food (starfish) at the moment.
I could find no white wingers or Caspian or even Caspian
look-a-likes amongst the lazy gulls but there were two 1cy Herring with very
creamy colours of the type that suggests a hybrid with Glaucous Gull.
One of these was ringed and proved to have hatched in a nearby colony and with
no reports of Glaucous Gulls this, or any previous, summer this (and a number
of previously similar and locally bred birds) shows that these are pale colour
forms and within the variation of Herring Gulls rather than hybrids.
A Lesser Black-backed Gull was perhaps the highlight.
Wintering birds in Norway are rare and less than annual in Oslo and are normally
young birds. This one had a black back and had previously been suggested to be
a fuscus (Baltic Gull) which is also a very rare subspecies in the south
of the country. Although the bird had a surprisingly little amount of streaking
on the head I could see nothing else to suggest fuscus with there being
an obvious contrast between black outer primaries and otherwise dark grey wings.
There were a few browner feathers in the wings especially the median primary
coverts which I initially took to be a sign of immaturity but the outermost
primary (P10) was also brown but was clearly an adult feather due to its large
mirror so these browner feathers must be older unmoulted feathers. The tail was also completely white and the
bill had no dark smudges that it has before full adulthood.
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| a very pale 1cy Herring Gull (gråmåke) that some may suggest is a hybrid with Glaucous Gull (polarmåke). Compare it to normally plumaged bird to its left. This bird was ringed as a nestling in a nearby colony and similar ringed birds in previous years seem to prove that these birds are just within the variation of Herring Gulls |
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| and another similar but unringed bird |
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| and an example of a very dark Herring Gull |
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| the adult Lesser Black-backed Gull (sildemåke) in front of the Munch Museum |
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| note that P10 is old an unmoulted, P9 has just been dropped and a new feather is growing out. The brown medium primary coverts and some secondaries are also unmoulted feathers contrasting with new, moulted, feathers |
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| the wings are much too grey to be fuscus |
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| note that the moult is symmetric in the left and right wings with the new P9 equally long |
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| and a brute of a young Great Black-backed Gull (svartbak) |
