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Flying and swimming animals cruise at a Strouhal number tuned for high power efficiency
Tuning cruise kinematics to optimize St seems to be a general principle of oscillatory lift-based propulsion of swimming and flying animals. Expand
Dragonfly flight: free-flight and tethered flow visualizations reveal a diverse array of unsteady lift-generating mechanisms, controlled primarily via angle of attack
It appears that stability of the LEV is achieved by a general mechanism whereby flapping kinematics are configured so that a LEV would be expected to form naturally over the wing and remain attached for the duration of the stroke, however, the actual formation and shed is controlled by wing angle of attack. Expand
The energetic cost of short flights in birds.
Using the doubly-labelled water technique, zebra finches Taeniopygia guttata engaging in repeated short flights were found to expend over three times the predicted flight expenditure derived from existing aerodynamic models. Expand
Tuning of Strouhal number for high propulsive efficiency accurately predicts how wingbeat frequency and stroke amplitude relate and scale with size and flight speed in birds
It is shown that St is a simple and accurate predictor of wingbeat frequency in birds, explaining 90% of the observed variance in a sample of 60 bird species and tuned by natural selection for high aerodynamic efficiency. Expand
The shape of pterosaur evolution: evidence from the fossil record
Pterosaur morphological diversification is, however, strongly age biased: rarefaction analysis shows that peaks of diversity occur in the Late Jurassic and Early Cretaceous correlated with periods of increased limb disparity. Expand
Narrow Primary Feather Rachises in Confuciusornis and Archaeopteryx Suggest Poor Flight Ability
Analysis of the flight feathers of early Mesozoic birds Archaeopteryx and Confuciusornis shows that the rachises were much thinner and weaker than those of modern birds, and thus the birds were not capable of flight. Expand
Evidence for energy savings from aerial running in the Svalbard rock ptarmigan (Lagopus muta hyperborea)
Changes of gait were associated with reductions in the gross cost of transport (COT; J kg−1 m−1), providing the first evidence for energy savings with gait change in a small crouched-postured vertebrate. Expand
The quality of the fossil record of Mesozoic birds
A dataset comprising all known fossil taxa is presented, suggesting that the broad outlines of early avian evolution are consistently represented: no stage in the Mesozoic is characterized by an overabundance of scrappy fossils compared with more complete specimens. Expand
Wing‐bone length allometry in birds
In addition to a general trend for larger birds to have longer wings, wing-bones and ta, their ta was a larger proportion of their b, and scaling equations are presented that can be used to predict M, ta and b from individual wing-bone lengths, which may be of use to palaeontologists wishing to reconstruct whole animals from single bones. Expand
Consequences of load carrying by birds during short flights are found to be behavioral and not energetic.
  • R. Nudds, D. Bryant
  • Environmental Science, Medicine
  • American journal of physiology. Regulatory…
  • 1 July 2002
The doubly-labeled water technique and video were used to measure the effect of mass loading on energy expenditure and takeoff performance in zebra finches that were making routine (nonalarm) short flights. Expand