... of producing total aerodynamic force equal to ∼4.3 times their own body weight, a value which significantly exceeds earlier estimates made for load-lifting dragonflies, and also for other volant taxa in sustained vertical load-lifting experiments. Maximum force production varied isometrically with body mass...

... and low-density heliox (mean=1.4 spikes cycle −1 ). However the spike amplitude, which we take to be an indication of the number of active motor units, increased in concert with the wing stroke amplitude, 1.7 times the value in air. We also challenged the hummingbirds using transient load lifting...

... geometric similarity. F ind scaled as muscle mass 1.036 , and this scaling exponent was not significantly different from unity or from the scaling exponent relating maximum load-lifting by flying dragonflies to their thorax mass. Thus, the combined effect of a change in the scaling of force output...

... as body mass –0.466 during free hovering, and as body mass –0.429 during maximal load-lifting for this assemblage. Although these values cannot be compared with phylogenetically controlled estimates for insects, it is likely that this decline in wingbeat frequency with increasing body mass is still much...