Skip to main content

Table 1 Mean values (± SD) and t-tests comparing the migration parameters of tracked Swan Geese during spring and autumn migration in the three different migration routes

From: Seasonal and regional differences in migration patterns and conservation status of Swan Geese (Anser cygnoides) in the East Asian Flyway

Routes Parameter Mean value ± SD df t P value
Spring Autumn
Dauria Region
(N = 81)
Departure (Julian date) 75.9 ± 5.8 257.9 ± 7.3    
Arrival (Julian date) 105.9 ± 4.1 322.2 ± 12.2    
Migration duration (day) 29.7 ± 6.2 64.1 ± 15.4 80 19.0  < 0.001
Migration distance (km) 2710.4 ± 221.0 2677.9 ± 159.7 80  − 1.2 0.216
Migration speed (km/day) 95.1 ± 20.3 44.9 ± 14.7 80  − 19.1  < 0.001
Number of stopover sites 2.6 ± 0.9 2.4 ± 1.0 80  − 1.6 0.117
Stopover duration (day) 25.7 ± 5.9 60.6 ± 15.1 80 19.8  < 0.001
Travel duration (day) 3.8 ± 1.1 3.2 ± 1.4 80  − 2.9 0.004
Travel speed (km/day) 735 ± 196.5 857.6 ± 250.3 80 3.3 0.001
Step length (km) 793.5 ± 200.6 858.6 ± 271.4 80 1.9 0.064
Straightness index 0.8 ± 0.0 0.8 ± 0.0 80  − 0.1 0.937
Central Mongolia
(N = 13)
Departure (Julian date) 74.8 ± 5.8 255 ± 8.0    
Arrival (Julian date) 95.8 ± 8.7 308.9 ± 7.6    
Migration duration (day) 20.8 ± 8.1 53.7 ± 9.0 12 8.5  < 0.001
Migration distance (km) 2927.8 ± 388.8 2603.8 ± 166.3 12  − 2.8 0.016
Migration speed (km/day) 159.8 ± 56.1 50 ± 10.5 12  − 6.6  < 0.001
Number of stopover sites 1.6 ± 0.7 1.9 ± 1.2 12 0.9 0.393
Stopover duration (day) 16.1 ± 7.4 50.1 ± 9.3 12 9.2  < 0.001
Travel duration (day) 4.6 ± 1.4 3.5 ± 1.9 12  − 1.7 0.114
Travel speed (km/day) 685.8 ± 224.1 891.4 ± 406.6 12 1.5 0.162
Step length (km) 1169.3 ± 249.2 1005.4 ± 317.1 12  − 1.8 0.098
Straightness index 0.8 ± 0.1 0.9 ± 0.0 12 2.6 0.024
Western Mongolia
(N = 10)
Departure (Julian date) 72.6 ± 4.0 256.1 ± 14.7    
Arrival (Julian date) 98.5 ± 5.2 301.4 ± 13.2    
Migration duration (day) 25.6 ± 5.3 45.2 ± 18.6 9 3.2  < 0.05
Migration distance (km) 3341.1 ± 284.9 3136.1 ± 242.4 9  − 2.4  < 0.05
Migration speed (km/day) 136 ± 30.3 85.8 ± 48.7 9  − 2.9  < 0.05
Number of stopover sites 1.8 ± 0.4 2.3 ± 0.9 9 1.5 0.177
Stopover duration (day) 19.5 ± 5.4 41.1 ± 18.8 9 3.6  < 0.01
Travel duration (day) 6.1 ± 1.5 4.1 ± 1.1 9  − 3.3  < 0.05
Travel speed (km/day) 572.8 ± 130.3 801.1 ± 177.0 9 3.1  < 0.05
Step length (km) 1224.7 ± 251.8 1039.3 ± 367.3 9  − 1.3 0.213
Straightness index 0.8 ± 0.1 0.9 ± 0.0 9 2.0 0.078