Table 1.
Seasonal differences in total speed of migration for different bird groups. Number of studies and sample size of individual tracks for which total speed of migration was available for both seasons. The seasonal median and first and third quartiles of bird group’s total speed of migration are shown. For individuals being sexed in the original studies, sex-specific medians and first and third quartiles are also presented. Qspeed of migration is calculated as the decimal logarithm of the ratio between spring and autumn total speed of migration.
| Bird group | Number of studies | Number of individuals | Total speed of migration in spring Median [25th, 75th quantile] (km/day) | Total speed of migration in autumn Median [25th, 75th quantile] (km/day) | Ratio between spring and autumn total speed of migration | Q speed of migration |
|---|---|---|---|---|---|---|
| Anseriformes (waterfowl) | 3 | 22 | 52 [43, 64] | 81 [67, 96] | 0.64 | −0.19 |
| Males | 2 | 17 | 52 [41, 64] | 84 [78, 93] | 0.67 | −0.17 |
| Females | 2 | 4 | 48 [44, 67] | 77 [62, 92] | 0.57 | −0.24 |
| Procellariiformes (tubenoses) | 1 | 10 | 668 [569, 743] | 779 [669,868] | 0.86 | −0.07 |
| Males | 1 | 3 | 726 [712, 737] | 881 [835, 905] | 0.82 | −0.09 |
| Females | 1 | 7 | 595 [550, 694] | 686 [649, 803] | 0.87 | −0.06 |
| Otidiformes bustards (only males) | 1 | 4 | 94 [90, 106] | 172 [166, 212] | 0.55 | −0.26 |
| Ciconiiformes storks (sex unknown) | 2 | 10 | 155 [113, 196] | 193 [159, 267] | 0.79 | −0.10 |
| Accipitriformes raptors | 11 | 66 | 184 [137, 236] | 154 [118, 210] | 1.20 | 0.08 |
| Males | 5 | 16 | 213 [162, 272] | 184 [151, 246] | 1.16 | 0.06 |
| Females | 9 | 42 | 182 [140, 218] | 147 [113, 187] | 1.24 | 0.09 |
| Charadriiformes waders | 11 | 47 | 253 [174, 338] | 185 [148, 210] | 1.37 | 0.14 |
| Males | 9 | 29 | 282 [198, 341] | 197 [160, 214] | 1.43 | 0.16 |
| Females | 4 | 8 | 271 [216, 340] | 180 [149, 376] | 1.51 | 0.18 |
| Charadriiformes gulls | 6 | 41 | 134 [88, 211] | 54 [23, 237] | 2.50 | 0.40 |
| Males | 3 | 12 | 106 [77, 198] | 60 [34, 165] | 1.78 | 0.25 |
| Females | 3 | 4 | 133 [114, 215] | 47 [19, 103] | 2.83 | 0.45 |
| Strigiformes owls (only males) | 1 | 5 | 59 [51, 63] | 165 [90, 220] | 0.36 | −0.44 |
| Apodiformes swifts | 2 | 17 | 363 [312, 600] | 236 [170, 301] | 1.54 | 0.19 |
| Males | 1 | 11 | 555 [338, 617] | 275 [200, 330] | 2.02 | 0.31 |
| Cuculiformes cuckoos | 1 | 3 | 85 [80, 104] | 62 [60, 66] | 1.37 | 0.14 |
| Males | 1 | 2 | 104 [94, 113] | 60 [60, 61] | 1.71 | 0.23 |
| Females | 1 | 1 | 74 | 71 | 1.04 | 0.02 |
| Coraciiformes “rollers” | 1 | 4 | 152 [146, 175] | 102 [93, 112] | 1.49 | 0.17 |
| Males | 1 | 2 | 193 [175, 211] | 102 [99, 106] | 1.88 | 0.27 |
| Females | 1 | 2 | 143 [140, 146] | 101 [94, 108] | 1.42 | 0.15 |
| Bucerotiformes “hoopoes” (only females) | 1 | 2 | 142 [132, 153] | 100 [90, 109] | 1.43 | 0.16 |
| Passeriformes songbirds | 25 | 170 | 154 [111, 211] | 90 [71, 130] | 1.71 | 0.23 |
| Males | 20 | 103 | 168 [112, 222] | 98 [72, 130] | 1.71 | 0.23 |
| Females | 11 | 35 | 174 [111, 242] | 90 [74, 120] | 1.93 | 0.29 |