Wednesday, 6 April 2016

Hybrid adult male Pallid x Hen Harrier

The omens didn't seem good at the start of the day - there were few birds in the air and no new concentrations of thrushes on the fields - but two birds in particular contrived to make today very exciting.
Maridalen was quiet with an ice mist over the still frozen lake but a pair of calling Cranes on the ice added to the atmosphere. The first exciting bird of the day was a species I had a hoping for but when I found it I was a bit shocked. Lapland Bunting is very scarce in Oslo although I have seen it three times previously in Maridalen and the first half of month April is the time to find one. The expectation is to find one feeding in a stubble field not singing from the top of a tree!! It was fortune that I looked at the bird - there was a lot of noise from singing Redwings but the closest bird from which song seemed to be coming was a lot smaller. I wasn't sure what I was expecting but immediately had a good feeling and got closer and yes a male Lapland Bunting. The song though was nothing like what I hear from breeding birds in the mountains and must be a subsong. It is just about audible in this video.


phone scoped

After this excitement in Maridalen I headed for Nordre Øyeren. Yesterday there was reported a considerable increase in bird numbers in Svellet including 4 Garganey. I was expecting even more birds today but was surprised to find considerably fewer and the Garganey had unfortunately gone.

Moving on to Årnestangen I had the days second surprise. I picked up a male harrier being harassed by a Crow and immediately thought Pallid due to long slender wings, small size and a pale grey plumage. As it flew closer towards me I saw it had too much black in the primaries for a Pallid but it didn't feel right for a Hen either. I concentrated on taking pictures (seriously missed the 500mm lens here) but could not see a black trailing edge to the secondaries and the extensive black on the primaries extended down to the base of the middle primaries. Studying my photos I see no other option than this being an adult male hybrid Pallid x Hen Harrier. Quite a few 1cy birds have been reported in Norway but this is the first adult although a couple of older males are reported from Sweden.
In the (poor) pictures can one also see that the hand comprises a short P10 (shorter than Hen?), long P9,8 & 7 and a P6 that is long enough to be called a finger but is not as long as one would expect on a Hen.

The annoying thing about this exciting bird is that I don't get a year tick out of it ;-(

at range it was looking like a Pallid Harrier (steppehauk)

the hand looks to only have 4 fingers and the black on the middle primaries extends to their base but there is too much black

very small

there is a thin dark grey band at the back of the secondaries but not as dark or broad as you would expect on a Hen Harrier

here we can see that the base of p10 on the upperwing is grey (black on Hen)

here we can see the "fingers". P10 (the outermost one) is probably too short for a Hen Harrier, P9,8,7 are OK for Hen Harrier but P6 is too short (although too long for a Pallid)

the absence of a broad dark trailing edge to the secondaries is again apparent

with a Herring Gull

Other birds were the 5 Gadwall still present plus my first Osprey of the year. I had 4 Great Grey Shrikes during the day and a return visit to Maridalen revealed 7 low flyover Cranes (had probably just flown up from a field) which judging by missing feathers are not the same birds I saw on Monday – this year is without a doubt a record for Cranes in Maridalen.
Pair of Cranes (trane) on the frozen, misty Maridalsvannet in the morning
The 7 Cranes in the afternoon
conditions must be quite dire for the Lapswings and these 3 were looking for food on the ice where a stream runs in
first Osprey (fiskeørn) of the year
these two 2cy Whooper Swans in Maridalen may well have been born in the valley last year
10 Goosander (laksand) were showing at close range
evidence of roosting Long-eared Owls at Årnestangen, Droppings and a wet pellet stuck up the tree

the view at Svellet - water levels are already rising

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