Table 2.
Correlation between arrival fuel load, tailwind components (TWC), relative humidity, sex and age. Separate models were run for both seasons, with each flight path aligned with a coastal destination (Fig. 1)
| Autumn migration | Wangerooge (43 km) | Juist (80 km) | Terschelling (177 km) | Caister-on-Sea (442 km) |
|---|---|---|---|---|
| Intercept | − 2.415 (− 2.521 to − 2.302) | − 2.405 (− 2.517 to − 2.301) | − 2.411 (− 2.523 to − 2.307) | − 2.413 (− 2.159 to − 2.307) |
| Tailwind components (linear) | 0.017 (0.009–0.025) | 0.003 (− 0.006 to 0.012) | − 0.004 (− 0.012 to 0.005) | − 0.006 (− 0.014 to 0.003) |
| Relative Humidity (linear) | 1.499 (− 0.104 to 3.215) | 2.136 (0.592–3.630) | 1.887 (0.359–3.516) | 1.832(0.290–3.474) |
| Relative Humidity (quadratic) | − 0.526 (− 2.089 to 1.033) | 1.600 (0.031–3.080) | 1.512 (0.064–3.046) | 1.445 (− 0.013 to 2.971) |
| Sex | 0.078 (− 0.066 to 0.222) | 0.071 (− 0.070 to 0.214) | 0.073 (− 0.068 to 0.215) | 0.073 (− 0.069 to 0.216) |
| Age | 0.517 (0.379–0.654) | 0.532 (0.393–0.672) | 0.522 (0.385–0.661) | 0.517(0.377–0.658) |
| Interaction (Sex:Age) | − 0.229 (− 0.417 to − 0.034) | − 0.230 (− 0.419 to − 0.036) | − 0.231 (− 0.420 to − 0.043) | − 0.227 (− 0.417 to − 0.036) |
| Spring migration | St. Peter-Ording (49 km) | Amrum (61 km) | Blåvand (155 km) | Mandal (429 km) |
|---|---|---|---|---|
| Intercept | − 2.199 (− 2.236 to − 2.004) | − 2.042 (− 2.157 to − 1.930) | − 1.985 (− 2.094 to − 1.879) | − 1.970 (− 2.077 to − 1.866) |
| Tailwind components (linear) | 0.024 (0.014–0.034) | 0.017 (0.003–0.030) | − 0.002 (− 0.017 to 0.015) | − 0.011 (− 0.026 to 0.005) |
| Relative Humidity (linear) | 1.518 (− 0.185 to 3.328) | 2.135 (0.425–3.999) | 2.443 (0.710–4.347) | 2.117 (0.394–3.998) |
| Relative Humidity (quadratic) | − 1.896 (− 3.685 to − 0.024) | − 0.533 (− 2.290 to 1.232) | − 0.617 (− 2.398 to 1.167) | − 0.245 (− 1.993 to 1.474) |
| Sex | − 0.238 (− 0.394 to − 0.083) | − 0.264 (− 0.422 to − 0.108) | − 0.283 (− 0.438 to − 0.128) | − 0.285 (− 0.441 to − 0.131) |
During autumn migration, the two-way interaction of sex and age was included. Mean estimates and CrI are presented for each explanatory variable (transformed values; see methods). Effects (CrI do not include zero) are shown in bold. Reference category for age was first-years and for sex males