Territory Among Wood Ants (Formica rufa L.) at Picket Hill

THE sketch-map (Text-fig. 1) shows the distribution in July, 1929, of the nests and trackways of the wood ants living in Dr T. G. Longstaff's bird sanctuary at Picket Hill on the edge of the New Forest near Ringwood, Hampshire. The ants were studied at irregular intervals between 1927 and 1929 during visits to Dr and Mrs Longstaff, to whom I owe a debt of thanks for hospitality, encouragement, and help in planning the survey. The wood ants lived only at one end of the garden, where a complex area of heather (Calluna vulgaris), birch (Betula alba), sallow (Salix caprea), oak (Quercus robur), and other plants, intersected by turfy paths and forming in places a dense undergrowth, has been kept for some years as a bird sanctuary (Longstaff, 1926). The ants were destroyed by the owner in 1930, owing to their repressive effect on the nesting birds. This can be seen in the sketchmap on which are marked the positions of the nests of willow wrens, whose nestlings are certainly liable to attack by ants (Longstaff, 1927), which have been observed elsewhere to keep away birds from pine trees (Hudson, 1923). The ants were named by Mr O. W. Richards, and the aphids by Mr F. Laing, to both of whom, and to Prof. E. B. Poulton, F.R.S., my thanks are due.