Table 2.

Muscle power output and associated subcomponents during the flapping flight of the cockatiel (Nymphicus hollandicus)

Flight speed (m s-1)
Variable135791113FP
Mass-specific pectoralis power output (W kg-1)125.1±24.196.1±21.973.5±10.176.9±11.396.6±22.5118.1±23.4155.6±29.26.3080.0004*
Positive work per wingbeat (J)0.23±0.040.18±0.040.14±0.020.16±0.020.21±0.030.26±0.040.32±0.056.9720.0002*
Total pectoralis length change (L)0.41±0.060.38±0.040.34±0.050.36±0.080.39±0.080.42±0.050.44±0.067.3080.0002*
Peak pectoralis force (N)31.8±9.127.0±8.222.3±5.223.3±4.228.3±4.534.6±5.338.9±4.97.5440.0001*
Wingbeat duration (ms)109.0±6.0118.1±8.4119.5±3.8130.9±6.4133.9±8.6135.0±7.8122.5±5.87.9270.0001*
Downstroke duration (ms)67.2±2.570.2±4.266.6±3.166.9±4.367.7±6.867.4±5.266.1±3.90.8210.5645
Upstroke duration (ms)41.8±4.047.9±6.352.9±3.264.0±4.666.3±4.267.5±6.656.4±6.114.180.0001*
EMG duration (ms)48.1±7.950.3±8.754.5±12.659.5±19.861.7±17.957.4±8.650.2±4.41.720.2624
EMG onset to force production (ms)9.4±4.98.7±4.38.6±3.86.6±1.07.2±2.27.6±2.76.6±1.041.020.4888
EMG onset to pectoralis shortening (ms)10.7±1.49.7±1.312.4±1.515.2±3.116.0±4.214.7±4.613.9±4.75.450.0291
Work loop shape factor0.52±0.080.53±0.060.55±0.060.56±0.060.55±0.050.53±0.050.54±0.051.010.4398
Pectoralis shortening velocity (L s-1)6.11±0.875.42±0.775.19±0.815.43±1.075.77±0.986.20±0.806.73±0.9813.120.0001*
  • 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).