Siberian
/ tristis Chiffchaff used to be a national rarity in Norway with few accepted
records. The lack of official records was due to there being a lack of
agreement as to how to identify the (sub)species rather than any real rarity
and the national rarities committee (NSKF) decided to remove it as a
description species a few years ago. Genetic work in other countries in NW
Europe has shown the species to be a regular migrant in late autumn and a
regular over wintering bird in the UK. I am firmly in the camp that a brown
chiffchaff that gives the classic piip call is a tristis and don’t think it
needs to be anymore complicated than this. At the end of October and in November
it is my experience that tristis are the commonest type of Chiffchaff around Oslo
(not that any type is common at this time of year).
There are
still those in Norway though who view tristis as a very complicated subject
with the spectre of eastern abientinus clouding the waters and this has led to
many people not subspecifically reporting birds as they can’t be bothered with
having to explain their identification. From what I can make out from all
recent research though if it looks like a tristis and most importantly sounds
like one then it is one.
The
reason for discussing this is that today there was not just one, but a flock of
three tristis at Fornebu! All the birds looked like tristis and the only sound
that came from them was the classic piip sound but whether all three called is
another thing. I played the song and calls of tristis to them and they responded
to this with one bird wing shivering. I also played the song of normal Chiffchaff
(which is very similar to tristis) and they definitely showed an interest but
there was no wing shivering. I managed quite a few pictures although the birds
were always quite high up and I am not certain how many different birds I have taken
pictures of. The pictures show the classic brown ear coverts and lack of any
green or yellow in the plumage with the exception of a yellowy tinge at the
base of the wing which is allowed.
the rusty/tobacco brown ear coverts and lack of yellow in the superciliu can be seen |
That these
birds have turned up now may be because we have had our first heavy frosts of
the winter over the last two nights; heavy enough that there was ice on the
edges of Maridalsvannet. The frost has also caused some movement of ducks with
7 species on Maridalsvannet yesterday with a single flock comprising 6
Goldeneye, 1 Common Scoter, 1 Tufted Duck and 1 Teal. The other species present
were Mallard, Goosander and the long staying Long-tailed Duck. 3 Guillemots
were also still present along with 3 Whooper Swans and 2 Mute Swans represented
a real wildfowl bonanza by local standards!
A Cormorant today. This is of the subspecies sinensis which is expanding in southern Norwway and has now become fra more numerous than carbo which breeds along the coats in northern Norway |
this Smew (lappfiskand) has been around a few days near Sandvika |
Two Snipe (enkeltbekkasin) yesterday on the icy edge of Maridalsvannet |
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