Format

Send to

Choose Destination
PLoS One. 2014 May 23;9(5):e98093. doi: 10.1371/journal.pone.0098093. eCollection 2014.

Hindlimb motion during steady flight of the lesser dog-faced fruit bat, Cynopterus brachyotis.

Author information

1
Department of Ecology and Evolutionary Biology, Brown University, Providence, Rhode Island, United States of America.
2
School of Engineering, Brown University, Providence, Rhode Island, United States of America; Department of Ecology and Evolutionary Biology, Brown University, Providence, Rhode Island, United States of America.
3
Department of Ecology and Evolutionary Biology, Brown University, Providence, Rhode Island, United States of America; School of Engineering, Brown University, Providence, Rhode Island, United States of America.

Abstract

In bats, the wing membrane is anchored not only to the body and forelimb, but also to the hindlimb. This attachment configuration gives bats the potential to modulate wing shape by moving the hindlimb, such as by joint movement at the hip or knee. Such movements could modulate lift, drag, or the pitching moment. In this study we address: 1) how the ankle translates through space during the wingbeat cycle; 2) whether amplitude of ankle motion is dependent upon flight speed; 3) how tension in the wing membrane pulls the ankle; and 4) whether wing membrane tension is responsible for driving ankle motion. We flew five individuals of the lesser dog-faced fruit bat, Cynopterus brachyotis (Family: Pteropodidae), in a wind tunnel and documented kinematics of the forelimb, hip, ankle, and trailing edge of the wing membrane. Based on kinematic analysis of hindlimb and forelimb movements, we found that: 1) during downstroke, the ankle moved ventrally and during upstroke the ankle moved dorsally; 2) there was considerable variation in amplitude of ankle motion, but amplitude did not correlate significantly with flight speed; 3) during downstroke, tension generated by the wing membrane acted to pull the ankle dorsally, and during upstroke, the wing membrane pulled laterally when taut and dorsally when relatively slack; and 4) wing membrane tension generally opposed dorsoventral ankle motion. We conclude that during forward flight in C. brachyotis, wing membrane tension does not power hindlimb motion; instead, we propose that hindlimb movements arise from muscle activity and/or inertial effects.

PMID:
24858194
PMCID:
PMC4032239
DOI:
10.1371/journal.pone.0098093
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Public Library of Science Icon for PubMed Central
Loading ...
Support Center