A comparison of Eurasian red squirrel distribution in different fragmented landscapes

摘要: Summary 1. The occurrence of species vulnerable to habitat fragmentation is likely depend on the size and separation fragments. However, shape function that relates these landscape parameters may be affected by other factors are less easily measured, in which case relationships with one area predict elsewhere only poorly. 2. We explored how well distribution red squirrels Sciurus vulgaris fragmented woodlands was predicted simple logistic regression models empirically derived landscapes. 3. Comparisons between predictions lead us identify thresholds fragment (> 10 ha) distance a source (< 600 m) where probability squirrel occupancy at least 0·9 all landscapes. These values reflect minimum requirements for home range dispersal worst study area. 4. For fragments < 10 ha (outside shared thresholds), developed could 17% cases, as such demography or quality might become relevant very small isolated fragments. 5. The predictive ability also improved when sizes observation fell within model developed. 6. Some gave correct between-year same despite noticeable changes regional population density. 7. When were met, we found used successfully elsewhere. In addition, threshold indicate large forest should they arranged favour landscape.