Table 1 Key phenological parameters of migration of A. a. pekinensis breeding in Beijing (N = 25)
Mean ± SD | Range | |
|---|---|---|
Autumn migration | ||
Departure from Beijing | Jul 17th ± 6 | Jul 3rd–Jul 25th |
Travel time (days) | 40 ± 14 | 22–69 |
No. stopover sites | 4 ± 1 | 2–6 |
Stopover time (days) | 71 ± 15 | 39–104 |
Total duration (days) | 111 ± 13 | 89–134 |
Migration distance (km) | 14,733 ± 775 | 13,432–16,096 |
Direct distance (km) | 11,738 ± 302 | 11,238–12,360 |
Detour (%) | 25.56 ± 6.71 | 15.35–37.31 |
Travel speed (km/day) | 423 ± 171 | 198–981 |
Migration speed (km/day) | 134 ± 17 | 109–170 |
Arrival at wintering area | Nov 5th ± 11 | Oct 16th–Nov 24th |
Duration of wintering period (days) | 100 ± 16 | 67–139 |
Spring migration | ||
Departure from wintering area | Feb 13th ± 12 | Jan 16th–Mar 6th |
Travel time (days) | 29 ± 11 | 14–56 |
No. stopover sites | 1 ± 1 | 1–4 |
Stopover time (days) | 36 ± 12 | 3–58 |
Total duration (days) | 64 ± 11 | 38–90 |
Migration distance (km) | 13,572 ± 999 | 12,411–16,321 |
Direct distance (km) | 11,817 ± 281 | 11,202–12,328 |
Detour (%) | 14.85 ± 8.00 | 3.32–36.26 |
Travel speed (km/day) | 528 ± 171 | 229–910 |
Migration speed (km/day) | 217 ± 34 | 156–327 |
Arrival at Beijing | Apr 18th ± 9 | Apr 7th–May 14th |
Duration in Beijing (days) | 90 ± 10 | 71–109 |