UNUSUAL PERCHING BEHAVIOUR BY TAWNY OWLS J. R .
MARTIN
At dusk on 24th July, 1986,1 was driving from Barrow to Hargrave (TL7762) when I saw a bird perched on a power cable erected over a field to my left. I instantly recognised it as a medium-sized owl, but was unable to define the species immediately. I stopped the car and, with the aid of 8 x 40 binoculars, was able to see quite clearly that it was a Tawny Owl (Strix aluco). T h e owl had n o difficulty in maintaining its balance and appeared quite at ease. There were other perching sites more commonly used by Tawny Owls available in the f o r m of tall posts supporting the line, but I noted that these had roof-shaped caps which may have made perching difficult. In common with many parts of south-west and west Suffolk there were no hedgerow trees which could afford cover and provide perching places for a bird that does not favour the open countryside but which needs to move across it from time to time. T h e owl flew into Wilsummer Wood eventually. This observation was not too surprising for I once saw a Barn Owl ( T y t o alba) perched in a similar m a n n e r near Martlesham. However, on 13th August at Bradfield St George (TL9160), when I was driving along a lane that skirted Free W o o d and approaching a slight bend in the road, I saw a Tawny Owl perched about 20 feet high on a power cable in front of me. I was able to stop the car directly underneath the bird and was afforded an exceptional good view. D u e to the fresh appearance of the plumage, which was not very dark and downy, I think it was a juvenile about 2 - 3 months old. Once again this bird had absolutely no difficulty in balancing. In this instance there were trees available for perching. T h e sight of a dead rabbit nearby suggested that the owl may have been disturbed whilst feeding on the carcase. Perching on telegraph wires or power lines is not unusual for some medium-sized birds such as the Kestrel (Falco tunninculus) and Woodpigeon (Columba palumbus) although Woodpigeons may have difficulty in maintaining their balance. T h e Little Owl (Athene noctua) habitually perches on overhead wires. Enquiries have confirmed that instances of Tawny Owls perching on overhead wires are either unusual or unrecorded, although D. Bunn ( p e r s . comm.) rightly points out that the Tawny Owl is basically nocturnal and perching on wires in the dark may occur more often than we realize. However, I am not aware of any other instance when a Tawny Owl has been recorded perching in such a manner. T h e distance between the two sites virtually rules out the possibility that the same bird may have been sighted on different occasions. Previous studies (see Witherby, etal., 1940; Mikkola, 1983; C r a m p , ed., 1986 & Martin, 1986, for example) indicate that Tawny Owls are strictly sedentary.
References C r a m p , S. (ed.) (1986). The Birds of the Western Palearctic, Vol. IV. Oxford University Press.
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Martin, G . R. (1986). Sensory capacities and the nocturnal habit of owls (Strigiformes). Ibis, 128, 266. Mikkola, H. (1983). The Owls of Europe. Poyser, Calton. Witherby, H. F., Jourdain, F. C. R., Ticehurst, N. F. & Tucker, B. W. (1940). The Handbook of British Birds, Vol. 11. Witherby, London. J. R. Martin 17 Moss Way West Bergholt Colchester C 0 6 3LJ
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