TENGMALM'S OWLS.
There were six of us. One had come prepared with a beautifully crafted walking stick, a straight piece of polished boxwood with a three pronged horn from a roe deer fixed to the top.
It was a cool day in April, there was still snow on the ground, as we were walking at about 1300 metres altitude. We were there to search out the nesting holes of a little known owl, the Tengmalm’s owl (Fr. Chouette de Tengmalm). We had spread out in a line across a forested hillside where the Tengmalms had been previously heard calling consistently, and trying - not very successfully - to keep the line coordinated as we scrambled through the undergrowth looking for suitable nesting holes.
It was not the first time I had been to this forest. Having never seen, or heard, a Tengmalm’s, I had been with a friend to spend the night early in February to listen and, hopefully, see this owl. It is the period when the males are making an easily identifiable territorial call, pu pu po po po po, and that night the calls were bubbling out around us. However, that night I never saw one; they are strictly nocturnal owls and only become active at dusk, so you have to be very lucky to catch sight of this small owl - slightly smaller than a Blackbird - before it is completely dark.
It had been special to be at night in a forest, listening out for the night sounds. We heard not only Tengmalm's – lower down in the valley Tawny owls were calling too - but there was the occasional bark of a deer, or the slightly unnerving call of a fox looking for a mate, and once I heard a strange yowling that was perhaps a wild cat.
Going back in the day we knew that we wouldn’t hear the call of the owl, but we were there to locate their nest holes, and try to assess how many of them had been used.
The holes are found in beech trees and have been made by black woodpeckers (FR. Pic noir) for their own nesting needs . Live beech is strong, so the tree will not be felled by the fierce winds that can blow at these altitudes. In the forest are many dead trees honeycombed by holes where the woodpeckers have been feeding on the insects inside; they are called bougies in French, but no woodpecker would choose to excavate a nest in a rotting tree.
A well worked tree, excavated by black woodpeckers. Jonathan Kemp
Black woodpeckers are big powerful birds, the largest woodpecker in Europe, nearly 50 centimetres tall and a wing span of more than 70. I’ve seen chips of wood 15 centimetres long lying on the ground made by their powerful beaks. They will also hammer down into the core of the tree to create a sheltered cavity for the chicks, and it is these that are sort after by the owls after the woodpecker has moved on. Many cavity nesting animals benefit from the ability of woodpeckers to create holes in trees, but we were here for the Tengmalms.
We found perhaps a dozen trees which showed the right sized holes, and also at a good height above ground. To make it obvious that they are being used by a protected species the trees were marked with red or yellow triangles. Some of the trees showed multiple holes, as in the photograph below.
It is then that the walking stick comes in handy. If you scratch the trunk, the owl will then look out of the hole, thinking that a predator – a pine marten for instance (Fr. Martre des Pins) - is climbing up, and on two of the trees we found this was exactly what happened. A strange little face appeared, the facial markings giving it a characteristic ‘astonished’ look, and peered down at us.
There is another method, somewhat more scientific, of looking into these holes by using a tiny camera called an endoscope which can be lifted up on the end of a pole and then manoeuvred into position to film down into the hole. We had come so equipped, but actually it is much harder to do than we had forseen. The cable has to be bent into a suitable curve so that it would slip into the hole, and on top of a waving 8 metres pole it was difficult to control.
Lowering the endoscope into a nesting hole.
Once or twice it was possible to get an image onto a connected mobile phone and we could see the remains of prey species that had been carried into a nest. In the end it was decided that this bit of technology was taking too long, and that we needed more practice, so back to the tried and tested method of trunk scratching.
Thomas J. trunk scratching; image Jonathan Kemp
It was a fascinating day, diving deeper into another of the forest's mysteries. I also would like to thank the local mayor, Marc, for his blessing to the research, for his enthusiasm - he visits the reserve nearly every day - and has intimate knowledge of the fauna to be found there and was able to guide us many of the nesting sites.
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