10.5061/DRYAD.BS1Q7
HÃ¥kansson, Jonas
Lund University
Jakobsen, Lasse
University of Southern Denmark
Hedenström, Anders
Lund University
Johansson, L. Christoffer
Lund University
Data from: Body lift, drag and power are relatively higher in large-eared
compared to small-eared bat species
Dryad
dataset
2018
Glossophaga soricina
Plecotus auritus
particle image velocimetry
2018-09-27T00:00:00Z
2018-09-27T00:00:00Z
en
https://doi.org/10.1098/rsif.2017.0455
1111832191 bytes
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CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
Bats navigate the dark using echolocation. Echolocation is enhanced by
external ears, but external ears increase the projected frontal area and
reduce the streamlining of the animal. External ears are thus expected to
compromise flight efficiency, but research suggests that very large ears
may mitigate the cost by producing aerodynamic lift. Here we compare
quantitative aerodynamic measures of flight efficiency of two bat species,
one large-eared (Plecotus auritus) and one small-eared (Glossophaga
soricina), flying freely in a wind tunnel. We find that the body drag of
both species is higher than previously assumed and that the large-eared
species has a higher body drag coefficient, but also produces relatively
more ear/body lift than the small-eared species, in line with prior
studies on model bats. The measured aerodynamic power of P. auritus was
higher than predicted from the aerodynamic model, while the small-eared
species aligned with predictions. The relatively higher power of the
large-eared species results in lower optimal flight speeds and our
findings support the notion of a trade-off between the acoustic benefits
of large external ears and aerodynamic performance. The result of this
trade-off would be the eco-morphological correlation in bat flight, with
large-eared bats generally adopting slow-flight feeding strategies.
BatDataDATThe file contains velocity vector fields of the wakes of two bat
species (Glossophaga soricina and Plecotus auritus) flying at various
speeds in a wind tunnel. The data is in .dat format, organized in columns
with spatial (x,y,z) coordinates followed by velocities (vx, vy, vz) in
each of the dimensions. The coordinate system is right handed with z in
the flow direction of the wind tunnel and y vertically upwards.
Accompanying xls files associate each sequence with individual, flight
speed and number of wing beats.