Monday, 9 September 2013

Resisting with ease

It has been family first the last few days and little time for birding. Today the schools have been closed due to elections (not quite sure that I see the causal relationship between elections and lack of education but that is how it is) and I took the girls cycling around Fornebu. There were still quite a few pipits and wagtails around but I only had singles of Tree Pipit (trepiplerke) and Yellow Wagtail (gulerle) amongst the Meadow Pipits (heipiplerke) and White Wagtails (linerle).

I have so far resisted the temptation (not that one really exists) to go look for this bird which was photographed three days ago near Drammen only half an hour or so from Oslo. A storm (OK a strong breeze) of internet birding frezy has blown up around it (not quite Birdforum standards but close) with Philadelpia Vireo (kanadavireo - a North American bird seen a handful of times on this side of the pond after westerly gales and usually on remote islands famous for producing rarities) being bandied about as the identity. Well the chance of me becoming a billionaire in the lottery must surely be higher than that and it transpires the pictures have been “fixed” with a resulting change in colours (hopefully the originals will be posted). It is clearly an odd looking bird but surely is just a Willow Warbler (or Chiffchaff?) with the colours looking odd. That must be the most plausible answer and without better pictures or further sightings we will never know as we cannot make any conclusions from just these two pictures (I have seen enough examples of how a single and especially edited picture can be entirely misleading).

EDIT: the unedited pictures have been posted on the net (see link to Sindre Molværsmyr's blog Oslo and Akershus Gulls on the right hand side of the page). If you download the original pictures from the link (the ones posted on the blog have also been "fixed" in photoshop) then you will see that the bird does still look very striking although the colours are not as bright as they appear in the other pictures. It definitely does look like a Philadelphia Vireo but the pictures are so few and unfortunately so bad that I don't think we will ever be able to conclude. We cannot see the bill properly and we don't get to see the whole bird i.e wings, tail or legs and we do not see the white edges to the greater coverts that Philadelphia Vireo should show (this could quite easily just be due to poor picture quality).

I also still believe that a Willow Warbler or Chiffchaff could in a limited number of poor quality pictures look like this. The observor has reported low, bright sun affecting the pictures and with such a bright green background from the trees we cannot be sure how the colours have been recorded digitally.

Scottish (Swedish) Bean Geese back in Akershus

Isn’t technology a wonderful thing? It is being used now in bird research and is adding to our knowledge of birds in ways that millions of hours of old fashioned ringing never could.

Followers of this blog will know about the Scottish ringed Bean Geese (sædgås) that migrate every spring through the Oslo area and which this summer have found to be breeding in mid Sweden close to the Norwegian border (it is also quite feasible that there are birds breeding on the Norwegian side of the border).

Carl Mitchell from the WWT informed me today that only one satellite tag is still transmitting and after after a period of silence has revealed that the bird had begun its autumn migration and arrived in Norway on 2 September. It was very close to the spring staging area although was using different feeding areas and a different roost site. In the spring the roost site is on sandbanks on the Glomma River but at this time of the year the sandbanks are not exposed so the autumn roost (this year at least) is a large lake in a forest. The two feeding areas which it has been using are interestingly 7km from each other and both have been used each day since 2 September. As with the spring records it seems that these birds are very site loyal. One of the feeding areas is a stubble field but the other which I did not visit appears to be a large possibly peat bog.

I was able to drive out tonight to check one of the fields that the bird has been using. When I arrived I had 6 Bean Geese flying in from the north (direction of the other field) and then a couple of hundred metres from a well used road in a large stubble field was a sizeable flock of fabalis Bean Geese. After several recounts I came to 144 birds with 7 having neck rings (6Y, 3X, 6X, 4Y, 6S, 7P, 6Z) which I was able to read and four having satellite neck collars (presumably one of these being the still transmitting one) although I could read no script on these (one did have a blue leg ring though identifying it as #16). Interestingly I was only able to identify one family with 2 juveniles although there could well have been more. 144 birds is only around half of the population so the remaining birds may include family groups and still be on the breeding grounds or using another migration route – only more sightings and more working satellite transmitters will answer these questions

Check out these two websites for more information on these geese:
Angus's Bean Goose blog
Two satellite collared fabalis Bean Geese (sædgås)

2 satellite collared birds. They are the left and right most of the three birds facing left with their heads up

a neck collared bird can be seen back left and a satellite collared bird centre facing right

part of the flock


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