Table 4 Example description of representativeness of different aspects in a population model of the common vole
Relevant aspects for population development | Data source | Representativeness | Evidence for geographical or other sources of variation | Remarks |
|---|---|---|---|---|
Reproduction (sex. maturity, gestation and lactation length, litter size) | Various habitats and laboratory studies | Generally representative for the common vole; the breeding season length used in the model is typical for Central Europe but may in reality be longer or shorter | Generally no evidence for geographical or other variability within Central Europe, but breeding season length varies depending on latitude and altitude and between years | Data about sexual maturity of male common voles was not available; therefore, data for Microtus agrestis were used |
Survival (survival rates, juvenile survival) | Mixed arable land in Poland and Germany | Mixed arable land in Central Europe | No evidence for regional variation available. Theoretically, influence of climate or predator abundance possible | Data from Poland were chosen for the model since they were based on large sample sizes and since survival rates were calculated using very reliable methods (CRM survival rates). Of all available data, these data were the most reliable ones. Data from Germany were used for habitat-specific survival |
Spatial behaviour (home ranges, dispersal) | Various habitats in Germany | Central Europe | No evidence for geographical variation and no mechanistic reason for such variation evident | Home range sizes in the model depend on food availability. In low food habitats, home ranges increase in size |