OPTIMAL WIDTH OF MOVEMENT CORRIDORS FOR ROOT VOLES - NOT TOO NARROW AND NOT TOO WIDE

1. The characteristics of male root vole movements as a function of co rridor width were tested in a 310 m long habitat corridor connecting t wo habitat patches. Detailed observations of movements were made by me ans of radiotelemetry and recording of footprints. 2. The highest conn ectivity, in terms of transference rate of individuals in the corridor system, was observed in the intermediate of three corridor widths tes ted (3 m, 1 m and 0.4 m). 3. The behavioural mechanism behind the lowe r connectivity of the narrowest corridor was a reluctance of voles to enter it, while linear progress in the widest corridor was hampered by a high frequency of cross-directional movements. 4. The relationship between corridor width and movement behaviour was unaffected by the si mulated presence of competitors and predators. 5. Our results challeng e the 'the-wider-the-better' principle of movement corridor design, an d provide elements for an understanding of the behavioural mechanisms underlying the movement ecology of individuals in linear habitats.