Tuesday, 11 September 2012

Fornebu delivers

The winds blew today and the birds came, only problem was that they were just Guillemots (lomvi) even though there were thousands of them.
Highest numbers of Guillemots were at the top of the Oslo fjord around Oslo (I was watching from Fornebu). It was difficult to estimate how many there were as they were flying in all directions, frequently landing and clearly doing circuits but there were probably a minimum of 500 (and one observer reported1855 in the evening). Fewer were seen further south and I believe the birds around Oslo are the culmination of all the birds flying north over the last few days. When they get to Oslo they run out of sea although some birds do keep going and I had one in flight close to the house which is 4km from the sea.
As you will see on the map below Oslo (and Fornebu) is right at the head of the fjord and to get that far north the birds have to go through a relatively narrow stretch by Drøbak. It seems that this is less of a problem for birds being blown north by strong winds but can be a problem when the birds try to return to open sea and have problems locating the exit.

Mass autumn arrivals of Guillemots have been a regular occurrence in recent years and unfortunately the inner Oslo fjord does not have enough food to support the large numbers that turn up and many of those that fail to exit to open sea end up starving to death. Ringing records show that these birds are British breeders.
You will also see on the map where Brentetangen is. This is closer to open sea which is why it usually turns up more sea birds than Fornebu although today they had far fewer Guillemots but did have a couple of skuas (joer) and Gannets (havsule)which were absent further north. I have also marked Ravn which overlooks real open sea and this evening they had 300 Fulmars (absent at Brentetangen and Fornebu), Sooty Shearwater (grålire) and Great Skuas  (storjo) (also absent further north) but far fewer Guillemots. Although the winds have died down a lot I have a hope that some of the birds seen at Ravn will have sneaked up to Brentetangen over night so I plan to be there early tomorrow morning...

In the nearly three hours I was watching from Rolfstangen at Fornebu the only interesting birds I had other than the hundreds of Guillemots were two sightings of Puffin (lunde) which could well have been the same bird doing a circuit, a single juvenile Arctic Tern (rødnebbterne) and three other terns which I failed to identify as they zipped past too far out. As was the case from my sessions at Brentetangen recently, I did not see a single Razorbill (alke) and no others were recorded around Oslo by other observers either. A single Long-tailed Duck (havelle) was resting on the sea and I had a distant Osprey (fisekørn).
1st winter Puffin with Guillemot

1st winter Puffin - note the small bill, very unlike a summer adult

one of many hundreds, if not thousands, of Guillemots

Earlier in the morning I had a really good half hour at Storøykilen where I eventually got to grips with the Black-tailed Godwit (svarthalespove) which is now in the company of a Bar-tailed Godwit (lappspove). Both birds were very confiding and gave a great opportunity to see these similar (unless flying) species side by side. Also here four Dunlin (myrsnipe) including two very trusting birds, a fly over Cuckoo (gjøk) and an unseen but vocal flyover Red-throated Pipit (lappiplerke).
juvenile Black-tailed Godwit,. The rich colours show it be of the race islandica

juvenile Bar-tailed Godwit (front) with the Black-tailed behind

in flight the differences between the 2 species is obvious and you can see how they get their names

juvenile Dunlin moulting into winter polumage (grey scapulars)

In the evening whilst watching my daughter play football a juvenile female Sparrowhawk (spurvehauk) flew over. This species seems to have enjoyed a very good breeding season with the population well on its way up again after having declined considerably following two cold winters in 2009/10 and 2010/11.

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