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Flying through gaps : How does a bird deal with the problem and what costs are there?

Henningsson, Per LU (2021) In Royal Society Open Science 8(8).
Abstract

Animals flying in the wild often show remarkable abilities to negotiate obstacles and narrow openings in complex environments. Impressive as these abilities are, this must result in costs in terms of impaired flight performance. In this study, I used a budgerigar as a model for studying these costs. The bird was filmed in stereo when flying through a wide range of gap widths from well above wingspan down to a mere 1/4 of wingspan. Three-dimensional flight trajectories were acquired and speed, wingbeat frequency and accelerations/decelerations were calculated. The bird used two different wing postures to get through the gaps and could use very small safety margins (down to 6 mm on either side) but preferred to use larger when gap width... (More)

Animals flying in the wild often show remarkable abilities to negotiate obstacles and narrow openings in complex environments. Impressive as these abilities are, this must result in costs in terms of impaired flight performance. In this study, I used a budgerigar as a model for studying these costs. The bird was filmed in stereo when flying through a wide range of gap widths from well above wingspan down to a mere 1/4 of wingspan. Three-dimensional flight trajectories were acquired and speed, wingbeat frequency and accelerations/decelerations were calculated. The bird used two different wing postures to get through the gaps and could use very small safety margins (down to 6 mm on either side) but preferred to use larger when gap width allowed. When gaps were smaller than wingspan, flight speed was reduced with reducing gap width down to half for the smallest and wingbeat frequency was increased. I conclude that flying through gaps potentially comes with multiple types of cost to a bird of which the main may be: (i) reduced flight speed increases the flight duration and hence the energy consumption to get from point A to B, (ii) the underlying U-shaped speed to power relationship means further cost from reduced flight speed, and associated with it (iii) elevated wingbeat frequency includes a third direct cost.

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Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Aerodynamics, Animal flight, Kinematics
in
Royal Society Open Science
volume
8
issue
8
article number
211072
publisher
Royal Society Publishing
external identifiers
  • pmid:34430051
  • scopus:85114601253
ISSN
2054-5703
DOI
10.1098/rsos.211072
language
English
LU publication?
yes
id
97ec1d54-22b7-4689-a126-5ad6869aa140
date added to LUP
2021-10-11 13:49:11
date last changed
2024-06-15 17:52:43
@article{97ec1d54-22b7-4689-a126-5ad6869aa140,
  abstract     = {{<p>Animals flying in the wild often show remarkable abilities to negotiate obstacles and narrow openings in complex environments. Impressive as these abilities are, this must result in costs in terms of impaired flight performance. In this study, I used a budgerigar as a model for studying these costs. The bird was filmed in stereo when flying through a wide range of gap widths from well above wingspan down to a mere 1/4 of wingspan. Three-dimensional flight trajectories were acquired and speed, wingbeat frequency and accelerations/decelerations were calculated. The bird used two different wing postures to get through the gaps and could use very small safety margins (down to 6 mm on either side) but preferred to use larger when gap width allowed. When gaps were smaller than wingspan, flight speed was reduced with reducing gap width down to half for the smallest and wingbeat frequency was increased. I conclude that flying through gaps potentially comes with multiple types of cost to a bird of which the main may be: (i) reduced flight speed increases the flight duration and hence the energy consumption to get from point A to B, (ii) the underlying U-shaped speed to power relationship means further cost from reduced flight speed, and associated with it (iii) elevated wingbeat frequency includes a third direct cost.</p>}},
  author       = {{Henningsson, Per}},
  issn         = {{2054-5703}},
  keywords     = {{Aerodynamics; Animal flight; Kinematics}},
  language     = {{eng}},
  number       = {{8}},
  publisher    = {{Royal Society Publishing}},
  series       = {{Royal Society Open Science}},
  title        = {{Flying through gaps : How does a bird deal with the problem and what costs are there?}},
  url          = {{http://dx.doi.org/10.1098/rsos.211072}},
  doi          = {{10.1098/rsos.211072}},
  volume       = {{8}},
  year         = {{2021}},
}