Succesfull breeding

Some pleasant surprises in Oslo and Maridalen regarding breeding birds means I am not completely over into the butterfly world just yet.

On the lake there was suddenly a single adult Mute Swan with 5 small young! This is just like last year in that they suddenly appeared but this year I was better prepared and had discovered the nest on 26 May. After that discovery of the nest though I had been unable on subsequent attempts to see any birds on it (although it was very difficult to see) and had only a record of single adult on 1 June and then a pair flying over the lake (not near the nest) on 9 June. I therefore assumed that the nesting attempt had failed and the birds had moved off. To suddenly see an adult with young was therefore a shock and it was equally surprising that I could not find the other adult anywhere on the lake. Has the male died or moved off? And if so how did the female managed to incubate and feed without me ever seeing her? And the pair I saw on x June – were they visitors? Perhaps the other pair that started nesting and then gave up? An answer to the first question is that P578 who I saw on Maridalsvannet on 29 April, and his ring was again read on 24 May, who is the male of the pair that bred last year and I assume the father of this years young was seen on 16 June at Fornebu where he and his mate had spent the winter – so it looks like he has left his mate to fend for herself! Did this happen before the eggs hatched?

Mute Swan (knoppsvane) - presumably female PC79 who bred here last year - with 5 small young but not with her mate (P578) who has flown down to Fornebu!

The Black-throated Diver pair (one of perhaps two on the lake) still have a single youngster and have moved quite a way from the nest with it.

Black-throated Diver (storlom) family

The ever growing cereal crop on the Lapwing field makes seeing the birds very difficult but yesterday I could see 3 (2 + 1) almost fully grown young which is a great relief but the fate of the two last nests remains unknown.

a nearly fully grown Lapwing (vipe) young

And finally, I had Red-backed Shrike in the Dale this year and it seems to be a nesting pair so fingers crossed for their success.

pair of Red-backed Shrikes (tornskate) in Maridalen

and the male on his own

A visit to Østensjøvannet today also revealed lots of young birds. Best of all were the Black-headed Gulls which have had their first successful breeding season (at least as a colony) for a few years with many large young on two islands. Great Crested Grebes, Coot and Mute Swans also had young (the later no larger than the ones I saw on Maridalsvannet) and surprisingly a female Goldeneye had 11 quite large young with her. This raises two questions – are they all hers? Perhaps unlikely. And how have so many survived so long? Normally the vast majority get eaten either by gulls or pike.

Black-headed Gulls (hettemåke) have had a successful breeding season at Østensjøvannet

and a male Gadwall (snadderand) which once again seems to have chosen Østensjøvannet to moult although this year there were no records earlier in the spring