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.
Trans. Suffolk Nat. Soc. 24