Tengmalm's Owl 2023

When I moved to Norway I had an expectation that Tengmalm’s Owl were reasonably common in the extensive forests and would be an easy bird to hear and not too difficult to see. I soon learned this is not the case as much of the forest is young commercial forest with little life but just as importantly the voles that the owls feed on have cyclical population variations and it is only in years with good numbers of rodents that Tengmalm’s Owls will breed in a specific area. Tengmalm’s do breed in the forests abutting Oslo but even in good years they are at low densities and in bad years none at all are heard. Tengmalm’s have been found to be quite mobile as they seek out the areas where rodents are experiencing cyclical highs and attempts at ringing them in the autumn often reveal them to be present on the coast and offshore islands.

In 2020 I decided to use the same methods as the ringers (playback) to see if there were owls moving through Oslo’s forests and indeed there were! Along with Per Christian we found Tengmalm’s Owls in 2020 and 2022 as well as Pygmy, Tawny, Long-eared and Hawk Owls which was a real eye opener. This year I have seen reports from further north of small numbers of Tengmalm’s being ringed so I thought I would give it a go at my favoured Oslo sight on Monday when it was forecast to be both cloudless and windless. I was a bit disconcerted when I could not hear any Pygmy Owls at dusk and feared this was a sign of there being no rodents but a Tawny Owl called half an hour after sunset and then 40 minutes later at 19:40 a Tengmalm’s called and I could hear that it was clearly moving towards me. The thermal imager then came into its own and allowed me to locate the owl. After this I could use my head torch and camera and had 10 wonderful minutes with the bird which was clearly a male as it sung itself a couple of times as well as giving the characteristic and quite eerie “tsyuck” calls. The Sound Approach is a great resource and explains lots of the different calls of Tengmalm's Owl including the tsyuck call. As can be heard in the video a Tawny Owl called close by and this caused the Tengmalm’s to be come alert and fly off.

when I had first located it with the thermal but the camera would not focus

manual focus

and the close enough to use autofocus

here it was singing and you can see it throat puffed out

I did not take any images with the thermal imager but here is a video I took on Værøy when there was Storm Petrel (havsvale) ringing;