The bird-life of the British Isles is largely based on a deciduous forest climax and the status of many species could be endangered by the current trend towards a mainly coniferous regime. This paper reports on the first five years of a long-term study of the habitat requirements of a woodland bird population during a period of change from broadleaved trees to a planting dominated by conifers, and recommends a compromise in management which while not too demanding from the economic standpoint, will enable much of our original woodland avifauna to adapt to the radical transformation which forest cover is likely to undergo in the future.