Not just owls

This post heralds a break from the last few weeks and (mostly) involves non-owl and non-Maridalen ornithological events 😊

Oslo is surrounded by spruce forest and one would therefore expect that crossbills would be a relatively easy to find and constant feature of these forests, however that is not the case. Spruce trees have a 4-7 year cycle between good seed years and this means that crossbills can often be completely absent if there are no seeds to be found and that is exactly how it is now. Last winter the forests were full of Crossbills (of all three species but predominantly Common Crossbill) as the autumn of 2019 had seen a record cone crop. But during 2020 the Crossbills vansished as the seeds fell from the cones. So, although there are still loads of cones hanging on the trees they are now too old and not of interest. As a result of this crossbills of all three species are very nomadic and are always searching for areas where their favourite coniferous tree has new, seed filled cones (each of the three crossbill species specialises on different trees species). They can travel huge differences in their search and at the moment their appear to be very few of any species in Norway. In the summer one can often hear flocks of crossbills flying over at great height as they search out the next suitable area.

My last record of a crossbill in Oslo’s forests was at the beginning of November and I can see no other observations since late November. I was therefore very surprised when I Sunday I found a flock of 7 Common Crossbills in a cemetery (I was there searching for a Rook which is less than annual in Oslo). The reason they were there is that there were a number of ornamental non-native spruce trees lining the paths and these were heavy with new cones. Common Crossbills can start breeding in January but I noted no song or other evidence to suggest that they were in the breeding mood but if there is enough food here then they may definitely give it a go.

Another interesting observation is wintering Water Rail in Oslo. The species winters around the coast of Norway but there are very few inland observations. This, of course, is because snow and ice means that there are not many suitable fresh water locations for the species. In Oslo, there is really one one suitable location for Water Rail which is Østensjøvannet which has quite extensive reedbeds. There have been quite a few records here in the summer months over the years and the species probably breeds annually. In the winter though (Jan-Feb) the lake freezes over completely and there are only records from 2015, 2019 and this year. I believe the species has been overlooked in the past as the favoured stream (which strangely enough refuses to freeze over) has probably not been visited in the winter before although it now being checked more regularly. A visit yesterday in snowy weather revealed two birds who seemed to be finding food amongst all the fallen branches in the stream.

In Maridalen heavy snow seems to have caused the Hawk Owls to change feeding grounds again but Pygmy Owl, Great Grey Shrike and one of the Buzzards are still to be found.

2 male and a female Common Crossbill (grankorsnebb), part of a flock of 7 birds that have found a tree heavy in young, seed-filled cones

the cemetary also had some very tame Roe Deer (rådyr)

Water Rail (vannrikse) - playing around with levels in PSE is becoming fun

and here I have probably over done it...

they were constantly searching for food

and seemed to find enough

the pale Common Buzzard (musvåk) still in Maridalen

and the Pygmy Owl (spurveugle) singing from a distant tree top

Maridalen from an unusual angle. This picture was taken on Sunday before the snow came from the middle of a frozen Maridalsvannet looking north. The lake has attracted hundreds of people on ice skates but that is now over with a thick layer of snow covering the ice

and finally a couple of pictures of the Beast on a frozen Dausjøen on Saturday when it was glorious weather