After some days in England without bins but where
Red Kites were so numerous that you nearly don’t notice them anymore it has
been nice to return to winter in Oslo and the possibility of finding a Red Kite
which really will be noticed.
Maridalen is still covered in snow but afternoon
temperatures up to +7C mean that it is slowly melting and there are now a few
areas of bare ground. Overnight frosts though means that it is still very
wintery in the mornings and few birds are arriving. They are arriving though
and I have been out every morning and recorded an increasing number of new species
– Mistle Thrush, Merlin, Kestrel, Redwing, Song Thrush, Dunnock, Meadow Pipit,
White Wagtail and Chiffchaff amongst others. Chaffinches and Skylarks are
singing strongly ensuring there is lots of noise. I had hoped for some raptors
movement and I have seen a few but not in the numbers of variety I hoped for.
Here are my eBird checklists from Maridalen the last
three days:
I have referred to a “cool/scarce and sensitive”
species which I have been watching this winter. You may have already guessed
that they were Long-eared Owls. I stumbled upon a roost in early January and
was able to follow it for many weeks. There were 1-4 birds using the roost on a
daily basis with normally 3 to be found and on only one occasion there were
none (and I used this opportunity to go in and collect a pellet). I discovered
the roost without needing my thermal imager although it was extremely useful in
helping me to thoroughly check the area and in the evenings to follow the
birds.The roost had broken up by the
end of February and I thought this was because they were paired up and thinking
of breeding but evening visits failed to reveal any singing birds. Towards the
end of Feb there had been an increasing number of records of clearly hungry
Long-eared Owls turning up daytime or being found injured around the coast of
Norway so I think the birds vanishing from the roost is most likely because
they have moved on searching for food. It is clearly not a rodent year in
southern Norway with very few records of singing owls of any species and they
are probably just thinking about surviving rather than passing on their genes.
The roost was surprisingly close to a footpath and
it is rather amazing that it wasn’t discovered by others especially as I know
that the initial sighting in December attracted a lot of attention. It would
have been nice to share the information and allow others to enjoy these
charismatic birds but unfortunately the population of undisciplined toggers in
Oslo is growing far too quickly and their behaviour with the Bearded Tits (tramping
down the reedbed to get a slightly better picture) and Hawk Owl (surrounding it
and throwing out dead mice on fishing line) this winter meant that there was
absolutely no way they could be allowed to know about the roost.
The four birds were all different in plumage with
one being especially dark and another especially pale. According to the
literature females are darker than males and I am quite sure there were 2 males
and 2 females. They were also different in how shy they were. The 2 presumed
females seemed to be unaffected by people or dogs in their vicinity whereas
both the males (paler birds) were far warier with one in particular often
flying off deeper into scrub and being therefore the bird seen least often.
I find it fascinating to wonder how these communal
roosts form- how do the birds find each
other? Is this a roost that has been used before? Why did they chose an area
close to people when they had a vast choice of more secluded areas near by? Did
the fact that I never saw them hunting in daylight and that they would wait
until long after sunset to leave the roost mean that they were not having problems
finding food?
I had 4 visits after dark two of which revealed no
birds and 2 revealed birds hunting from either posts or trees. I had expected
to see birds hunting in flight but maybe with the snow there were not rodents
to be found in the open areas. I also stayed by the roost until after sunset on
three occasions with the birds only becoming active about 30 minutes after
sunset and after some preening they would silently fly off and only once did I
then refind a bird which I watched and filmed hunting.
I of course took far too many photos and videos and here is a (too) quickly chosen selection shown in more or less chronological order although the videos are randomly inserted with the 4 best at the beginning
3 birds together
here are the two palest birds which must be males
the darkest bird and presumed female
the second dark(er) bird
I very rarely saw them in flight and this was the only picture I got
the darkest bird
a thermal imager picture of one of the birds hunting from posts near a house
the darkest bird and the one that often perched most in the open and closest to the path
2 birds in snow
the darkest bird again
the second dark bird
the darkest bird
and the two dark birds together (darkest is lowest)
the darkest bird now with one of the paler birds
a great comparison of male and female
darkest bird
two birds in this picture
easier to find them in the thermal imager
a pale bird
and this is I think the second darker bird. I have not spent a lot of time studying my pictures trying to individually identify the birds I saw on different days but some of the birds have been difficult to classify as dark or pale which makes me wonder whether more than 4 birds have actually used the roost
There was only one occasion when I had a bird active during the day. Here it is in the open and had been mobbed by a Magpie and adopted a very thin and upright stance
Fornebu stopped being an airport in 1998 and it was
always planned that the land would be used for housing but the “development”
has thankfully taken a long time although things have sped up recently and the
last areas of derelict land are now being prepared for building work. Fornebu
will never be as good for birds as it used to be and the nature reserves are
not large enough or well enough protected from disturbance to have much of an
effect.
Ringed and Little Ringed Plovers thrived on the
derelict ground with a number of pairs of both species. Ringed Plovers have already
returned but it will be a month before the first Little Ringed return. There is
perhaps still enough stony ground for some to try to breed this year but
whether they will be successfully is another matter. Yesterday I found 4 Ringed
Plovers loafing around on what was a car park but which will soon be built
upon. I was able to enjoy them at very close range and mull over the thought
that this may be my last opportunity to do so.
Ringed Plover (sandlo), a female if I am not mistaken
there is still so much snow that there will not be a breeding attempt until it has melted which may take a couple of weeks
