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. 2015 Jun 3;10(6):e0125659. doi: 10.1371/journal.pone.0125659

Table 1. Departing bird trajectories.

Freely—departing bird trajectories (n = 18) Chased bird trajectories (n = 31) Statistical comparison (unpaired t-test)
Flight speed at t c = 0.3s 3.0 ± 0.8 (mean ± s.d.) 3.9 ± 1.1 p = 0.0039
Maximum flight speed (m s-1) 5.4 ± 1.4 6.2 ± 1.3 p = 0.0629
t ma: t c at maximum average acceleration, t c ≤ 0.3s (s) 0.17 0.08 -
Acceleration magnitude at t ma (m s-2) 9.1 ± 4.8 14.6 ± 5.7 p = 0.0025
Overall maximum acceleration (m s-2) 19.6 42.3 -
Kinetic + potential energy at t c = 0.3s (J kg-1) 35.1 ± 2.1 35.2 ± 3.0 p = 0.6812
Kinetic energy at t c = 0.3s (J kg-1) 4.7 ± 2.6 8.3 ± 4.2 p = 0.0046
Potential energy at t c = 0.3s (J kg-1) 30.4 ± 1.1 27.2 ± 2.3 p < 0.0001
Mean kinematic power at 0 ≤ t c ≤ 0.3s (W kg-1) 18.6 ± 6.8 20.3 ± 8.4 p = 0.5050
Maximum mean kinematic power 0 ≤ t c ≤ 0.3s (W kg-1) 33.0 39.4 -
Maximum angular velocity (degrees s-1) 258.8 ± 107.4 334.8 ± 149.2 p = 0.0627
Flight speed at maximum angular velocity (m s-1) 1.5 ± 0.7 2.2 ± 1.4 p = 0.0556
Maximum gravity-adjusted centripetal force (body weights) 0.9 ± 0.3 1.6 ± 0.7 p = 0.0002
Flight speed at maximum gravity-adjusted centripetal force (m s-1) 3.1 ± 1.7 4.2 ± 1.5 p = 0.0242