Species/habitat relationships and their responses at different scales are important aspects of ecological and conservational research. We studied the occurrence of hazel grouse Bonasa bonasia males in a forest reserve over a 10-year period at varying scales and population densities, using two sets of habitat descriptions. Avoidance of pine Pinus sylvestris was the only habitat effect in the hazel grouse/habitat analyses that was significant through all scales, seasons and densities. Thus, in spite of long-term data on a well-known species and detailed vegetation descriptions, only a few clear patterns relating to hazel grouse habitat selection were found at the relatively small scales analysed. We conclude that the non-significant relationships were due to the generally suitable composition and small variation of habitats within the study area, and that significant results may not be expected within the scales analysed and with the methods used. Thus, to find associations between animal species and habitats, a suitable study area must include a certain degree of habitat variation and the relationships should probably be examined at a scale equal to or larger than the home-range of the species in question, or considerably larger if population data are available. The results are discussed in relation to other studies and the applicability of the habitat descriptions and census techniques for conservation of hazel grouse populations in managed forests are discussed.