| (i) |
LONG |
Not included |
Migration simulated as a clock-and-compass strategy with single steps between each stopover and winter sites (8 steps in total). Each step is drawn randomly between the vectors observed in the tracked birds. This scenario is valid both for adults following the same route as they did as juveniles and for adults using a clock-and-compass strategy directly |
| (ii) |
SHORT |
Not included |
Same as (i) LONG above, except that the step length is 100 km. Directions are drawn randomly from a circular distribution that fits the concentrations at each stopover. |
| (iii) |
SHORT_Mort |
Direct mortality |
Migration of adult birds with birds crossing mountains or ocean dying, i.e. tracks are discontinued after crossing. Otherwise as (ii) SHORT. |
| (iv) |
SHORT_Dir_Change |
Change of migration direction |
Migration simulated as a clock-and-compass strategy with birds encountering impassable mountains or ocean choosing another random direction to circumvent it if possible. This scenario is valid both for adults following the same route as they did as juveniles and for adults using a clock-and-compass strategy directly |
| (v) |
LONG_Juv_Mort |
Juvenile mortality |
Migration of adult birds following the routes followed as juveniles but with juvenile mortality taken into account. Thus, juvenile birds crossing mountains or ocean are assumed to die and thus, these tracks are removed. Step length as in (i) LONG. |
| (vi) |
SHORT_Juv_Mort |
Juvenile mortality |
As above (v) LONG-Juv-Mort, except that steps are modelled as in (ii) SHORT. |
