Table 1.
Summary of migration phenology for all tracked Northern wheatears
| Bird | Start of autumn migration [Julian day] | Arrival at wintering grounds [Julian day] | Total stopover duration [days] | Total speed of migration in autumn [km/day] | Start of spring migration [Julian day] | Total stopover duration [days] | Total speed of migration in autumn [km/day] |
|---|---|---|---|---|---|---|---|
| 7902 | 216 | 318 | 45 | 152 | 98 | 7 | 262 |
| 7910 | 233 | 315 | 33 | 163 | 94 | 18 | 279 |
| 7916 | 229 | 317 | 38 | 173 | 91 | 25 | 166 |
| B070 | 226 | 315 | 38 | 181 | 112 | 9 | 324 |
| E552 | 216 | 307 | 45 | 136 | 100 | 7 | 271 |
| E553 | 229 | 322 | 53 | 139 | 89 | 18 | 182 |
| E801 | 221 | 315 | 43 | 287 | 90 | 20 | 160 |
| E823 | 227 | 331 | 60 | 247 | 84 | 26 | 198 |
Note, that tracking towards Alaska in spring ceased after birds entered areas with 24 h daylight. Total stopover duration and total speed of migration were therefore only calculated by departure date from the wintering ground to arrival at the last location estimate during spring migration (cf. Fig. 1 and Additional file 4 for more details)