Yesterday, I took only my second trip of the year
out to the islands of the Oslofjord and it was a fairly rewarding trip even if
it was bugs more than birds that featured. I had hoped for a few waders or
maybe a Y-b Warbler but the only warbler I had was a single Chiffchaff and
there were only two waders – a Knot and a Common Sandpiper. Knot is a good Oslo
bird though and a late Common Tern was also noteworthy.
The undoubted bug highlight was a Hummingbird
Hawkmoth which fed just metres away from me and gave me my best ever views of
the species. Bug #2 was Brown Hairstreak at a, for me, new location for the
species. I noticed that there was a lot of blackthorn (slåpetorn) and decided
to walk close to it to see if there were any butterflies and sure enough two
females flew up and then landed in trees and showed very well.
Today a quick check of Nordre Øyeren and Maridalen
revealed my first Great Grey Shrikes of the autumn at both sites indicating that
the species is now on the move.
Hummingbird Hawkmoth (dagsvermer)
note the probiscous inside the flower
it really is long!
female Brown Hairstreak (slåpetornstjertvinge)
and the other female
juvenile Common Tern (makrelterne)
much is written about the Oslo fjord being "dead" but the large numbers of Cormorants are witness to large numbers of fish
juvenile Knot (polarsnipe)
Great Grey Shrike (varsler) at Nordre Øyeren
and the bird in Maridalen..
which was chasing a Yellowhammer (gulspurv)
a late Osprey (fiskeørn) with a flock of Jackdaws (kaie)
Buzzard (musvåk) in Maridalen
a Coot (sothøne) on Maridalsvannet. This is only my second record there and only the fourth ever. I noticed a bird in the middle of the lake whilst out with the Mrs on Sunday and took some pictures but only looked at them today and found out what it was.
Goosander (laksand) on Maridalsvannet. Probably 2 family groups
As my more regular readers will know I have a
growing interest in butterflies which has really taken off in the last 3 years.
Many birders develop this interest plus one for dragonflies as the hot summer
months are a quiet time on the birding front yet a good time for insects so our
interest is drawn to the most bird like insects there are.
I have confined my interest in butterflies to just
recording the ones I see on my regular birding trips and have only once
travelled to specifically look for new butterfly species which was a complete
flop as can be read here. Never-the-less I have now seen (and all are self-found)
60 species in Norway out of what would be appear to be a total list of 100
species. This compares to my bird list of 316 species (281 self-found) out of 505
species. The stats therefore quite clearly make me a far more competent
butterflyer than birder! 😊
This year I have had a bit of a focus on finding
Hairstreaks in and around Oslo and have had quite a few sightings of
White-letter (alme-), Purple (eike-) and Brown (slåpetornstjertvinge). The
Brown Hairstreaks have been particularly photogenic whilst nectaring whilst the
other two have always been annoyingly high up in trees. I have therefore been
drawn back to the Brown Hairstreaks a few times. As I am seeing them at Fornebu
which in addition to being good for birds also has a dog park I was able to persuade
Mrs OB that we should make a trip there with the Beast on Saturday. It was
initially a bit cloudy but after the sun came out I spent some time looking
downwards whilst my better half power walked the dog.
I was a bit distracted from butterflies by a Great
Snipe which I disturbed from long grass and managed some good flight shots of
this scarce local passage bird.
My target butterfly species showed well though and I
got to see 3 female and 2 male Brown Hairstreaks which allowed me to appreciate
that they can be separated on the underwing and not just the upperwing. I also
saw Small Blues (dvergblåvinge) from what in Norway is a very rarely recorded
second generation. The only other blues were Common Blues (tiriltungeblåvinge)
which were common but came in such a variety of sizes and hues that I found
myself looking at each one to confirm identity.
A particularly large blue butterfly caught my
attention and I followed it until it landed. Through the camera I saw it had
tails! My initial thought was that maybe I was looking at a strange colour aberration
of a hairstreak but I then saw its underwing and realised that was not the case
at all and this was something new and different. The tails were VERY long and
the pattern of the underwing just screemed exotic! I only know of a single
species of blue butterfly with a tail and remembered seeing pictures here on Peter Law's excellent blog. A
quick google search confirmed that I had indeed found a female Long-tailed
Blue! And a further search revealed no other published Norwegian records and
also that it had no official Norwegian name!
The pictures I got were rather good and the
butterfly was in pristine condition. The species is a long distance wanderer
and is appearing in the UK in greater and greater numbers. Oslo is however a
lot further north than any other records and the possibility of it having
arrived “unnaturally” has to be considered. Apparently caterpillars of this
species are known to be found in peas (mangetout) imported from Kenya so there
is the possibility that someone has found a caterpillar and thrown it out into
their garden and it has then pupated and emerged? I don’t know whether a
genuine migrant or an imported caterpillar is more likely but have I enjoyed in
bathing in all the congratulations I have received on Facebook for finding a
new species for the country 😊
I have read that butterflies develop tails as a
defence mechanism against birds. Birds think that the wings are the head of the
butterfly and therefore try to grab at that end. As they are part of the wing
they easily break off allowing the butterfly to escape. This explains why lots
of hairstreaks are missing their tails but of course it is a defence strategy
than can only be used once. My pictures of the Long-tailed Blue whose tails were
still intact (which suggests she emerged recently) show that she was moving
them around a lot presumably all as part of the act to fool predators.
female Long-tailed Blue - just look at those "tails"
and looks how the tails can be moved around
Brown Hairstreak (slåptornstjertvinge) this female has lot its "tails" and a lot of tis wing to a bird but has escaped alive
another and immaculate female
and here a video grab showing the upperwing. Females have the red mark which is lacking in the males I have previously pictured
and a third female. Compare to the male in the next shot. The underwing of the female is more brightly coloured and the tails perhaps slightly longer
a male Brown Hairstreak (sex confirmed by seeing upperwing)
Small Blue (dvergblåvinge) is not a species I see often but a number of my records have been of the rarely recorded second generation
mating Common Blues (tiriltungblåvinge) taken with the bazooka from 2.5m away
and with an iphone 8 at about 10cm
a noticeably pale male Common Blue
it is not often that a Great Snipe (dobbeltbekkasin) is relegated to last place in a blog post ;-)
