Data, Text and Supporting files for the PLoS One paper "The Aerodynamic Cost of Head Morphology in Bats: Maybe Not as Bad as It Seems"

This is the data, text and all supporting files for the PLoS One paper entitled 'The Aerodynamic Cost of Head Morphology in Bats: Maybe Not as Bad as It Seems' (doi: 10.1371/journal.pone.0126061) The upload contains all supporting files, matlab scripts as well as the different versions of the paper (including the revisions and reviewer comments). The data reported in the paper were previously released on the Bristol Research Data Repository under doi:10.5523/bris.ulxh4ri19mgs1hzn58a6194xi ABSTRACT OF THE PAPER: At first sight, echolocating bats face a difficult trade-off. As flying animals, they would benefit from a streamlined geometric shape to reduce aerodynamic drag and increase flight efficiency. However, as echolocating animals, their pinnae generate the acoustic cues necessary for navigation and foraging. Moreover, species emitting sound through their nostrils often feature elaborate noseleaves that help in focussing the emitted echolocation pulses. Both pinnae and noseleaves reduce the streamlined character of a bat's morphology. It is generally assumed that by compromising the streamlined charactered of the geometry, the head morphology generates substantial drag, thereby reducing flight efficiency. In contrast, it has also been suggested that the pinnae of bats generate lift forces counteracting the detrimental effect of the increased drag. However, very little data exist on the aerodynamic properties of bat pinnae and noseleaves. In this work, the aerodynamic forces generated by the heads of seven species of bats, including noseleaved bats, are measured by testing detailed 3D models in a wind tunnel. Models of Myotis daubentonii, Macrophyllum macrophyllum, Micronycteris microtis, Eptesicus fuscus, Rhinolophus formosae, Rhinolophus rouxi and Phyllostomus discolor are tested. The results confirm that non-streamlined facial morphologies yield considerable drag forces but also generate substantial lift. The net effect is a slight increase in the lift-to-drag ratio. Therefore, there is no evidence of high aerodynamic costs associated with the morphology of bat heads.