Now that Redpolls have been lumped into one species I think
it is time to do the same with Crossbills. Are Common Crossbill, Scottish
Crossbill and Parrot Crossbill really different species or are they just
different forms along a clinal range where dominant food source is the determining
factor? My memory of reading what the Sound Approach wrote is that Common
Crossbill contains so many distinct populations with different calls and bill
sizes that they could just as easily be considered different species. Scottish
Crossbill has always been a farce (don’t they go “missing” in some years and
then turn up again with a slightly different call?) that I think was driven by
Britain’s desire to have an endemic species but now that Red Grouse has been
split from Willow Grouse then Britain has its symbolic endemic so Scottish Crossbill
can be allowed to fade away. Parrot Crossbill at the extreme end does look and
sounds very different from the opposite extreme of Common Crossbill but there
are many, many birds that are somewhere in between and you (I) really struggle
to put a label on them other than “crossbill”.
This last week I have seen a nice variety of crossbills that
brought back my dislike of the species group. At the weekend we had some
crossbills in nice mature pine (as opposed to spruce) forest. This would
normally mean that they are Parrots and in Norway Parrots are called furukorsnebb
(mean Pine Crossbill) whereas Common are grankorsnebb (meaning Spruce Crossbill).
Looking at them in the binoculars it was not immediate what they were and
neither were their calls particularly helpful one way or the other. Zooming in
on photos I identified them as Parrots but definitely not the largest billed of
their kind. Maybe they are a far better fit for Scottish? Is it not the case
that crossbills develop bills to suit the food they are specialising in so a (sub)population
that has good access to pine grows a larger bill than one that has access to
spruce or larch?
Then on Monday I had classic Parrot and Common together
(both in bill size and call) plus a bird that was somewhere in between.
male Parrot Crossbill (furukorsnebb) from Ringebu at the weekend
the bill does look huge on this one
the female looks classic Parrot but the male not quite
here they are looking good
but at this angle not so
And pictures from Monday closer to home:
this male is definitely not a Parrot although in the field that was my original conclusion
this pair with their smaller bills without parallel upper and lower mandibles are clearly Common Crossbills
the male of the same pair
a pair of Parrots Crossbills - large billed, bull necked classic birds
the male of the pair
this should be the same pair but the male is now looking quite different
this should be the same male who again looks different depending on angle
the female is the Parrots but the male is one of the Common Crossbills (possibly the first bird I have pictures and not from the pair)
here it is easier to see that the male is not a Parrot
the differences are perhaps easier to see here
This video has the two pairs and also the calls. The deeper call we hear most often is the Parrot and the higher pitched call is from the Common
here a still warm road kill juvenile Common Crossbill from Maridalen today. The bill looks to be fully developed
We have now had two nights without frost and along with
southerly winds I have been expecting a flood of migrants. Of course, that has
not been the case and viz mig has been a particular disappointment with just a
few flocks of Pink-footed Geese, 2 Cranes and a Kestrel. I had a real hope for
a few raptors but it is clearly still too early still (and I have this “surprise”
every year at this time….).
Despite the lack of viz mig there has been an arrival of new
birds. Dunnocks and Redwings are suddenly back and singing from woodland, White
and Grey Wagtail are suddenly wagging away and there are considerably more Lapwing, Mistle
Thrushes, Chaffinches, Bramblings and a large Twite flock in Maridalen.
Surprisingly though there are no Robins back yet but that must happen soon.
The Hawk Owl has been showing very well as it exploits a
rich source of Bank Voles (klatremus) and I was very happy to be able to film
it dismembering and then eating one.
A trip to Østensjøvannet was very birdy with lots of noisy
gulls and various wildfowl with a pair of Smew being the absolute highlight.
The video I have long wanted to capture showing the beheading, entrails removing and swallowing of a vole
Hawkie on a wire
and on its way down for what ended up being an unsuccessful vole hunt
this video has a few sequences with it giving its call that I also heard frequently when it first turned up in November
male Smew (lappfiskand)
pair
and with a Grey Heron (gråhegre)
3 male Teal (krikkand)
and a close of up another bird
the Heron was not at all popular with the Black-headed Gulls (hettemåke)
Goosander (laksand) are also back
3 species of returning gulls on the ice and 2 male Goosander
Grey Wagtail (vintererle) is back in the Dale
as is Dunnock (jernspurv)
and Redwing (rødvingetrost)
and a large flock of Twite (bergirisk) is having a stop off on its migration
and the first White Wagtail (linerle) of the year
not in Maridalen and not a good picture but I cannot remember capturing Parrot (furukorsnebb) and Common Crossbill (grankorsnebb) together before
Canada and Greylag Geese in Maridalen suddenly became very alert when this fox appeared
The last week saw the greatest migration day of the spring,
at least as far as quantity is concerned, when the Pink-footed Geese decided
that conditions were favourable and took off on mass from Denmark early in the
morning before passing over Oslo some hours later. Thursday was the day and is
the earliest ever date for the big day which 30-40 years ago used to occur in
the first week of May. Over the course of 3 hours I counted over 9000 birds
heading first NNE over Maridalen and then after the wind changed from southerly
to northerly they started heading ENE. I made a real effort to check every
flock hoping for something white or red but could only find a few Barnacles and
just a single Greylag amongst them. When you spend so long scanning the skies
you expect to notice other signs of viz mig but amazingly apart from some Wood
Pigeons and some gulls I just had a single Buzzard and two Sparrowhawks which
were probably local birds.
Passerine migration has picked up slightly with a few Mistle
Thrushes, Twite and Reed Buntings now around in Maridalen but it can feel very
birdless at times.
My major excitement this week has been with owls again but
they will be the subject of their own post very soon.
hundreds of Pink-footed Geese (kortnebbgås) streaming over Maridalen on Thursday
here with a Barnacle Goose (hvitkinngås) amongst them
the juvenile Common Crossbills (grankorsnebb) are growing and will probably leave the nest within a week. Note however that they have yet to develop the crossed bill of their parents
food time
with the sunny days there are suddenly insects and Goldcrest (fuglekonge) are appearing openly in bushes to exploit this new food source
Lesser Spotted Woodpeckers (dvergspett) are getting quite vocal as they search for mates. I had two very noisy birds yesterday which as far as I could see were both females
a pale Buzzard (musvåk)
my first Adder (hoggorm) of the year
and my first Oslo Small Tortoiseshell (neslesommerfugl)
