Horizontal flight of a swallow (Hirundo rustica) observed in a wind tunnel, with a new method for directly measuring mechanical power
Author
Summary, in English
A swallow flying in the Lund wind tunnel was observed from the side and from behind, by two synchronised highspeed video cameras. The side-view camera provided a record of the vertical position of a white mark, applied to the feathers behind and below the eye, from which the vertical acceleration was obtained. The rear-view camera provided measurements of the mean angle of the left and right humeri above horizontal. From these data, the force acting on the body, the moment applied by each pectoralis muscle to the humerus and the rotation of the humerus were estimated and used to analyse the time course of a number of variables, including the work done by the muscles in each wing beat. The average mechanical power turned out to be more than that predicted on the basis of current estimates of body drag coefficient and profile power ratio, possibly because the bird was not flying steadily in a minimum-drag configuration, We hope to develop the method further by correlating the mechanical measurements with observations of the vortex wake and to apply it to birds that have been conditioned to hold a constant position in the test section.
Publishing year
2000
Language
English
Pages
1755-1765
Publication/Series
Journal of Experimental Biology
Volume
203
Issue
11
Links
Document type
Journal article
Publisher
The Company of Biologists Ltd
Topic
- Biological Sciences
Status
Published
Research group
- Animal Flight Lab
ISBN/ISSN/Other
- ISSN: 1477-9145