Fig. 3: Comparison of model versions.

a–d, A visual fit of simulated data (dashed lines) to observed data (solid lines) for the blackbird population size for model A (a), model B (b), model C (c) and model D (d). Simulated data are presented as mean values with 95% prediction intervals. e, A comparison of model fits between main model versions. Comparisons were on the basis of distances between observed and simulated data for each dataset. For each dataset, distances were normalized by dividing each model’s distance by the maximum across all model versions. A normalized distance of ‘1’ thus indicates that the model showed the largest distance between observed and simulated data (that is, the worst fit). Lower normalized distances indicate a better fit to the data.