Muscle power output and associated subcomponents during the flapping flight of the cockatiel (Nymphicus hollandicus)
| Flight speed (m s-1) | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Variable | 1 | 3 | 5 | 7 | 9 | 11 | 13 | F | P |
| Mass-specific pectoralis power output (W kg-1) | 125.1±24.1 | 96.1±21.9 | 73.5±10.1 | 76.9±11.3 | 96.6±22.5 | 118.1±23.4 | 155.6±29.2 | 6.308 | 0.0004* |
| Positive work per wingbeat (J) | 0.23±0.04 | 0.18±0.04 | 0.14±0.02 | 0.16±0.02 | 0.21±0.03 | 0.26±0.04 | 0.32±0.05 | 6.972 | 0.0002* |
| Total pectoralis length change (L) | 0.41±0.06 | 0.38±0.04 | 0.34±0.05 | 0.36±0.08 | 0.39±0.08 | 0.42±0.05 | 0.44±0.06 | 7.308 | 0.0002* |
| Peak pectoralis force (N) | 31.8±9.1 | 27.0±8.2 | 22.3±5.2 | 23.3±4.2 | 28.3±4.5 | 34.6±5.3 | 38.9±4.9 | 7.544 | 0.0001* |
| Wingbeat duration (ms) | 109.0±6.0 | 118.1±8.4 | 119.5±3.8 | 130.9±6.4 | 133.9±8.6 | 135.0±7.8 | 122.5±5.8 | 7.927 | 0.0001* |
| Downstroke duration (ms) | 67.2±2.5 | 70.2±4.2 | 66.6±3.1 | 66.9±4.3 | 67.7±6.8 | 67.4±5.2 | 66.1±3.9 | 0.821 | 0.5645 |
| Upstroke duration (ms) | 41.8±4.0 | 47.9±6.3 | 52.9±3.2 | 64.0±4.6 | 66.3±4.2 | 67.5±6.6 | 56.4±6.1 | 14.18 | 0.0001* |
| EMG duration (ms)† | 48.1±7.9 | 50.3±8.7 | 54.5±12.6 | 59.5±19.8 | 61.7±17.9 | 57.4±8.6 | 50.2±4.4 | 1.72 | 0.2624 |
| EMG onset to force production (ms)† | 9.4±4.9 | 8.7±4.3 | 8.6±3.8 | 6.6±1.0 | 7.2±2.2 | 7.6±2.7 | 6.6±1.04 | 1.02 | 0.4888 |
| EMG onset to pectoralis shortening (ms)† | 10.7±1.4 | 9.7±1.3 | 12.4±1.5 | 15.2±3.1 | 16.0±4.2 | 14.7±4.6 | 13.9±4.7 | 5.45 | 0.0291 |
| Work loop shape factor | 0.52±0.08 | 0.53±0.06 | 0.55±0.06 | 0.56±0.06 | 0.55±0.05 | 0.53±0.05 | 0.54±0.05 | 1.01 | 0.4398 |
| Pectoralis shortening velocity (L s-1) | 6.11±0.87 | 5.42±0.77 | 5.19±0.81 | 5.43±1.07 | 5.77±0.98 | 6.20±0.80 | 6.73±0.98 | 13.12 | 0.0001* |
Values are inter-individual means ± S.D.; N=5 († indicates N=2).
Significant effects of flight speed at the P<0.05 level after a Bonferroni correction for the table are marked with an asterisk (repeated-measures ANOVA with individual and speed; d.f.=6).