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RESEARCH ARTICLE
Contents Vol 56(5)

Aerodynamic cleanliness in bats

R. D. Bullen A C and N. L. McKenzie B
+ Author Affiliations
- Author Affiliations

A 43 Murray Drive, Hillarys, WA 6025, Australia.

B Department of Environment and Conservation, PO Box 51, Wanneroo, WA 6065, Australia.

C Corresponding author. Email: bullen2@bigpond.com

Australian Journal of Zoology 56(5) 281-296 https://doi.org/10.1071/ZO08059
Submitted: 13 July 2008  Accepted: 4 December 2008   Published: 29 January 2009

Abstract

In this paper we examine morphometric attributes of the airframes of 24 species of bat from Western Australia. In particular, we consider anatomical features of the ear, head, body and tail related to lift and drag optimisation as well as airflow separation control. We provide an assessment of the relative cleanliness of the species and a range of lift and drag coefficient values for use in metabolic power output modelling. The species assessed have aerodynamic cleanliness optimisations that are appropriate to the range of Reynolds’ numbers in which bats fly. Head/body relative cleanliness was consistent with, and functionally appropriate to, aspects of species foraging niche such as foraging strategy. Cleanliness of face and fineness ratio of head and body were found to be related to minimum foraging drag. Blending of the wing and body, the presence of a wing/body fillet and the texture of the pelage were found to be important. The aerodynamic optimisation of ears and tail membrane were found to correlate with foraging strategy. The interceptors had optimisations for minimum drag generation consistent with their higher foraging flight speed. Rather than being optimised for minimum drag, the air-superiority bats’ tails and ears were consistent with their highly agile but slower-foraging flight speeds. Surface bats were characterised by the absence of optimisations for low drag. The frugivore plus the nectarivore and the carnivore studied appear to be discrete optimisations.


Acknowledgements

We thank C. L. Bullen and M. H. McKenzie for field assistance and the Western Australian Department of Environment and Conservation for providing laboratory facilities. J. McRae prepared the original artwork in Fig. 4. Nadine Guthrie provided the artwork for Fig. 6 and also the modification to Fig. 4a.


References

Abbott I. H. , and von Doenhoff A. E. (1959). ‘Theory of Wing Sections.’ (Dover: New York)

Arlettaz, R. (1993). Tadarida tenotis’ tail. Myotis 31, 155–162.
Belbin L. (1995). ‘PATN Technical Reference.’ (CSIRO Division of Wildlife and Ecology: Canberra.)

Bullen, R. D. , and McKenzie, N. L. (2001). Bat airframe design – flight performance, stability and control in relation to foraging ecology. Australian Journal of Zoology 49, 235–261.
| Crossref | GoogleScholarGoogle Scholar | Chang P. K. (1976). ‘Control of Flow Separation.’ (McGraw-Hill: New York.)

Churchill S. (1998). ‘Australian Bats.’ (Reed New Holland: Sydney.)

Clarke, K. R. , and Green, R. H. (1988). Statistical design and analysis for a ‘biological effects’ study. Marine Ecology Progress Series 46, 213–226.
| Crossref | GoogleScholarGoogle Scholar | Freeman P. W. (1998). Form, function and evolution in skulls and teeth of bats. In ‘Bat Biology and Conservation’. (Eds T. H. Kung and P. A. Racey.) pp. 140–156. (Smithsonian Institute Press: Washington, DC.)

Gardiner, J. , Dimitriadis, G. , Sellers, W. , and Codd, W. (2008). The aerodynamics of big ears in the brown long-eared bat Plecotus auritus. Acta Chiropterologica ,in press
Glauert H. (1926). ‘The Elements of Aerofoil and Airscrew Theory.’ (Cambridge University Press: London.)

Grzelewski, D. (2001). Flying foxes, foresters on the wing. The Australian Geographer 62, 90–103.
Hoerner S. F. (1965). ‘Fluid-dynamic Drag.’ (Hoerner Fluid Dynamics: Brick Town, NJ.)

Hoerner S. F. , and Borst H. V. (1975). ‘Fluid-dynamic Lift.’ (Hoerner Fluid Dynamics: Brick Town, NJ.)

Itoh, M. , Tamano, S. , Iguchi, R. , Yokota, K. , Akino, N. , Hino, R. , and Kubo, S. (2006). Turbulent drag reduction by seal fur surface. Physics of Fluids 18, 065102.
| Crossref | GoogleScholarGoogle Scholar | Kuchemann D. (1978). ‘Aerodynamic Design of Aircraft.’ (Pergamon Press: London.)

Lamar, J. E. , and Frink, N. T. (1982). Aerodynamic features of designed strake-wing configurations. Journal of Aircraft 19, 639–646.
| Crossref | GoogleScholarGoogle Scholar | McKenzie N. L. , and Bullen R. D. (2008). Beccari’s free-tailed bat, Mormopterus beccarii. In ‘Mammals of Australia’. 3rd edn. (Eds S. Van Dyck and R. Strahan.) pp. 486–487. (Reed New Holland: Sydney.)

McKenzie N. L. , and Churchill S. K. (2008). Northern long-eared bat, Nyctophilus arnhemensis. In ‘Mammals of Australia’. 3rd edn. (Eds S. Van Dyck and R. Strahan.) pp. 516–517. (Reed New Holland: Sydney.)

McKenzie N.L. and Muir W.P. (2000). Bats of the southern Carnarvon Basin, Western Australia. Records of the Western Australian Museum Supplement No. 61, 465–477.

McKenzie, N. L. , and Rolfe, J. K. (1986). Structure of bat guilds in the Kimberley mangroves, Australia. Journal of Animal Ecology 55, 401–420.
| Crossref | GoogleScholarGoogle Scholar | McKenzie N. L. , and Start A. N. (1989). Structure of bat guilds in mangroves: disturbance and determinism. In ‘Patterns in the Structure of Mammalian Communities’. (Eds D. W. Morris, Z. Abramski, B. J. Fox and R. Willig.) pp. 167–178. (Texas Tech University Press: Lubbock, TX.)

McKenzie, N. L. , Fontanini, L. , Lindus, N. V. , and Williams, M. R. (1995). Biological inventory of Koolan Island, Western Australia. 2. Zoological notes. Records of the Western Australian Museum 17, 249–266.
Nowak R. M. (1994). ‘Walker’s Bats of the World.’ (Johns Hopkins University Press: Baltimore.)

Pedersen, S. C. (1993). Cephalometric correlates of echolocation in the Chiroptera. Journal of Morphology 218, 85–98.
| Crossref | GoogleScholarGoogle Scholar | CAS | PubMed | Pennycuick C. J. (1989). ‘Bird Flight Performance: A Practical Calculation Manual.’ (Oxford University Press: Oxford.)

Pennycuick, C. J. , Heine, C. E. , Kirkpatrick, S. J. , and Fuller, M. R. (1992). The profile drag of a hawk’s wing measured by wake sampling in a wind tunnel. Journal of Experimental Biology 165, 1–19.
| Crossref | GoogleScholarGoogle Scholar | Richards G. C. (2008). Northern bent-winged bat, Miniopterus schreibersii orianae. In ‘Mammals of Australia’. 3rd edn. (Eds S. Van Dyck and R. Strahan.) pp. 509–510. (Reed New Holland: Sydney.)

Schmitz F.W. (1942). ‘Aerodynamics Of The Model Airplane. Part 1. Airfoil Measurements.’ Translated as Redstone Scientific Information Center RSIC-721 (1967).

Simons M. (1999). ‘Model Aircraft Aerodynamics.’ (Nexus Special Interests: Hemel Hempstead, UK.)

Sneath P. H. A. , and Sokal R. R. (1973). ‘Numerical Taxonomy. The Principles and Practice of Numerical Classification.’ (W.H. Freeman: San Francisco.)

Speakman J. R. , and Thomas D. W. (2003). Physiological ecology and energetics of bats. In ‘Bat Ecology’. (Eds T. H. Kunz and M. B. Fenton.) pp. 430–490. (University of Chicago Press: Chicago.)

Spencer H. J. (2008). Northern blossom bat, Macroglossus minimus. In ‘Mammals of Australia’. 3rd edn. (Eds S. Van Dyck and R. Strahan.) pp. 426–427. (Reed New Holland: Sydney.)

Start A. N. , and McKenzie N. L. (2008). Western false pipistrelle, Falsistrellus mckenziei. In ‘Mammals of Australia’. 3rd edn. (Eds S. Van Dyck and R. Strahan.) pp. 541–542. (Reed New Holland: Sydney.)

Swartz S. M. , Freeman P. W. , and Stockwell E. F. (2003). Ecomorphology of bats: comparative and experimental approaches relating structural design to ecology. In ‘Bat Ecology’. (Eds T. H. Kunz and M. B. Fenton.) pp. 257–300. (University of Chicago Press: Chicago.)

Swift S. M. (1998). ‘Long-eared Bats.’ (T. & A.D. Poyser: London.)

Tian, X. , Iriarte-Diaz, J. , Middleton, K. , Galvao, R. , Israeli, E. , Roemer, A. , Sullivan, A. , Song, A. , Swartz, S. , and Breuer, K. (2006). Direct measurements of the kinematics and dynamics of bat flight. Bioinspiration & Biomimetics 1, S10–S18.
| Crossref | GoogleScholarGoogle Scholar | PubMed | Torenbeek E. (1976). ‘Synthesis of Subsonic Airplane Design.’ (Delft University Press: Netherlands.)

Van Dyck S. , and Strahan R. (Eds) (2008). ‘The Mammals of Australia.’ 3rd edn. (Reed New Holland: Sydney.)

Viswanath, P. R. (2002). Aircraft viscous drag reduction using riblets. Progress in Aeronautical Sciences 38, 571–600.
| Crossref | GoogleScholarGoogle Scholar | Wilson D. E. (1997). ‘Bats in Question.’ (Smithsonian Institution Press: Washington, DC.)