Feeding habits of the Great Grey Shrike in winter

S T O K O E (1961) and Harrison (1961) described Great Grey Shrikes Lanius excubitor persistently chasing small birds and the latter suggested that hunting flight might be more usual than the surprise swoop from a perch which The Handbook of British Birds infers is the regular method of capture. In fact, such chases are not uncommon, but Steinfatt {1941) was more correct when he stated that the Great Grey Shrike hardly ever actually catches small birds except by surprising them. T h e same comment was made by Fellenberg (1958) who watched unsuccessful pursuits of a Meadow Pipit Anthus pratensis and a tit Varus jp. The following experiences of my own near Frondenberg, Germany, also illustrate this. On 22nd March 195 5, for example, I saw a Great Grey Shrike pursue a House Sparrow Passer domesticus a long way over grassland until the latter escaped around the corner of a building. Again, on the afternoon of 19th December 195 9,1 watched a Great Grey Shrike following a Bullfinch Pjrrhula pyrrhula for more than a quarter of an hour. The Bullfinch, calling anxiously all the time, was circling round a small shrubbery of willows and a row of poplars on the banks of the frozen Ruhr. It soon seemed exhausted and repeatedly tried to reach the tare branches of the trees, but the shrike succeeded in preventing this. Nevertheless, the Bullfinch was always able to avoid the swoops of the shrike and in the end the latter gave up the chase, and returned to the top of a high tree. Then a little later I saw the shrike not far away trying unsuccessfully to catch a Wren Troglodytes troglodytes which was flying along a narrow strip of broken-down sedge on the opposite "bank of the river. Soon afterwards, however, it flew past with a House Sparrow in its bill and some time later I observed it carrying a vole or mouse in its claws. There was a thick cover of snow on the ground at that time and more was falling, while the temperature had been well below freezing for several days; I shall show later that food shortage in hard weather may cause this persistent chasing of small birds.