Table 1. Predictors and the three best Ordinary Least Squares models (i.e. with ΔAICc<2) explaining the variation in the population trends of birds.
| Factor | 1 | 2 | 3 | b (SE) | Importance |
| Intercept | • | • | • | −0.886 (1.076) | 1.000 |
| Continent | • | • | • | + | 0.999 |
| Farmland | • | • | • | −0.610 (0.364) | 0.997 |
| FID | • | • | • | 2.087 (1.254) | 0.995 |
| Continent: FID | • | • | • | + | 0.984 |
| Body mass | • | • | • | −1.701 (0.826) | 0.961 |
| Continent: Body mass | • | • | • | + | 0.881 |
| FID: Body mass | • | • | • | + | 0.879 |
| Migration | • | • | −0.039 (0.196) | 0.474 | |
| Latitude | −0.002 (0.008) | 0.342 | |||
| Continent: Migration | • | + | 0.207 | ||
| Continent: Latitude | + | 0.121 | |||
| Continent: Farmland | + | 0.090 | |||
| k | 8 | 9 | 10 | ||
| AICc | 596.2 | 597.5 | 597.9 | ||
| ΔAICc | 0.00 | 1.30 | 1.74 | ||
| w i | 0.261 | 0.136 | 0.109 | ||
| R2 | 0.27 | 0.27 | 0.29 |
Variables included in the models are indicated by a filled circle (•). The number of parameters (k), AICc, ΔAICc, Akaike weight (w i), and coefficient of determination (R2) are shown below each model. Model averaged estimate (b) among the 391 candidate models and the relative importance are shown for each predictor. “+” symbol indicates factors with more than one level. See Methods for further details.