Leucistic Coot and Common Chiffchaff

It really is awful weather at the moment and after having had a good arrival of ducks on Maridalsvannet I thought a trip to Østensjøvannet may pay off and the bird hide there would also offer protection from the elements. It was very birdy with lots of commoner waterfowl and 54 Wigeon was a high count but I had dared to hope for more. See my eBird checklist here.

A leucistic Coot turned up last year and I had seen it again earlier this year but it was a real surprise to see it today and see that it had turned almost completely white – I had not appreciated that the degree of leucism was something that changed over time.

In other news the dna results of the interesting Chiffchaff that I discovered in the spring have come back and show that it was not an Iberian as I had hoped but a Common Chiffchaff. What is interesting though is that it was of the nominate subspecies collybita rather than abietinus which is the subspecies that is considered to breed in Scandinavia. I don’t know the research behind this traditional view but the Chiffchaffs that move through the Oslo area in late autumn and which are textbook abietinus have always been noticeably different than the local breeding birds (especially on call). Whether all local breeders are collybita or this bird was a vagrant will only be discovered if more dna work is done. Both mitochondrial and nuclear markers were tested and both showed the bird to collybita so ruled out a hybrid as well – the classic dna test is only of the mitochondrial which only reveals who the mother is so never actually rules out the hybrid option.

The leustic Coot (sothøne) with a normal bird

despite the rain this Sparrowhawk (spurvehauk) was still out hunting

this male Kestrel (tårnfalk) was more of a surprise and looked to be heading purposefully south

Little Grebes (dvergdykker) have become a regular autumn feature at Østensjøvannet

there were still three juvenile Lesser Black-backed Gulls (sildemåk) hanging around although the adults are already long gone

this bird doesn't seem to have moulted any feathers whereas the previous bird had some newer mantle feathers

for comparison a young Herring Gull which has also moulted some mantle feathers. This is also a pale bird with milky coffee coloured primaries