Abstract
Studies of the movement of marked brown trout in a section of the Aberfeldy River between 31 January 1972 and 6 February 1974 showed that the home range of 1 + and older trout was about 60 m of river; that of 0 + fish was about 370 m. Some fish strayed outside this restricted range. The age structure of trout populations in sections of the Aberfeldy River at different times of the year suggests that 0 + fish moved up-stream into small tributaries but did not spawn there. The trout probably spawned throughout the main river.