OSLO BIRDER: More chaffy chiffs

Another day of sun and fantastic weather with no wind and a heavy frost. I thought a walk in the forest would pay off with sounds travelling but after 2 and a half hours I realised that sounds may travel but only if there is anything making a sound. The forest was dead quiet. I checked four Hazel Grouse (jerpe) sites using sound and got no response although I did scare up one bird.

I also played Pygmy Owl (spurveugle)calls. In areas where there are Pygmy Owls then the passerines respond to the call and come to investigate and mob the owl. Therefore if you get a passerine response then you know that there are owls in the area. Well the passerines confirmed what I already knew but no owls responded or showed themselves. The passerines in question were a few tits and Goldcrests (fuglekonge) but I had no finches and the only woodpecker in the whole walk was a single Black. Definitely not a successful trip.

Maridalsvannet was without a ripple except for those made by a calling party of three Whooper Swans (sangsvane) which looked very majestic.

Heading to Fornebu I discovered that the sheltered waters were already frozen and this gave me a belief that there would be good numbers of ducks on the main fjord. Think again! I did have a few Velvet (sjøorre) and Common Scoter (svartand) but best birds were 2 Little Auks (alkekonge) and 4 Guillemots (lomvi). No divers.

I visited Hengsenga again hoping to refind the Chiffchaffs (gransanger) and record their calls. It was very frosty there but the Chiffhcaffs were still present. I had three birds (possibly four) and all were green seemingly western birds today although I only saw two well as they were feeding low in the grass. They were also quite quiet although I did hear a few “sweeo” calls indicating an eastern (abietinus?) origin. Interestingly one had a call that was (very) similar to tristis. I didn’t see the bird making the sound particularly well as it stayed in the grass nearly continually but it definitely wasn’t the grey/brown bird from yesterday and looked to have green tones in its plumage on the back/mantle and also on the breast. There were a couple of Chiffchaffs where the calling bird was and I took a picture of the bird that I think was calling but cannot be 100% sure it is the same bird. Never-the-less the bird that was giving the tristis like call was far from what I would expect a classic tristis to look like.

I was able to record the call by taking a video. You will need to turn the sound up a lot to hear it.

I’ve made my first attempt at making a sonogram using the Raven Lite software from The Cornell Lab of Ornithology. As the recording was so poor (and I have extracted the sound rather inneficiently by using the record function on my phone) the sonogram is not, I think, good enough to tell us anything conclusive. What it does show is a pretty straightline at a frequency of around 4250Hz.

What does this mean? Well I’m not really sure and think a better recording is needed. To my ears the sound was not quite as “sad” as a normal tristis but then again my ears are not famed for hearing subtle differences. I try to work more with these birds and my sound recording abilities. It will be very interesting to see how long they survive here. There are a few Wrens aswell in the grass and reeds so presumably there is a good supply of insects but prolonged minus temperatures will surely spell the end of them either by killing them or forcing them to move south.

This is the bird I believe was giving the tristis like call and if it wasn't then has the same look. This bird has too many green tones on the back and especially the breast sides to go down as a tristis