Bat airframe design: flight performance, stability and control in relation to foraging ecology

R. Bullen; N. L. McKenzie

doi:10.1071/zo00037

Bat airframe design: flight performance, stability and control in relation to foraging ecology

Australian Journal of Zoology ◽

10.1071/zo00037 ◽

2001 ◽

Vol 49 (3) ◽

pp. 235 ◽

Cited By ~ 48

Author(s):

R. Bullen ◽

N. L. McKenzie

Keyword(s):

Foraging Ecology ◽

Tail Length ◽

Area Ratio ◽

Length Ratio ◽

Foraging Strategies ◽

Flight Performance ◽

Systematic Classification ◽

Stability And Control ◽

And Control

We tested the airframes of a community of microbats in terms of flight performance, stability and control, and present the first systematic classification of bat flight manoeuvres. The tail, ears and main-wing all contributed to these airframe functions. In combination, six airframe ratios (aspect ratio, wing loading, tail area ratio, ear area ratio, tail length ratio and ear length ratio) provided robust predictions of species’ foraging microhabitats and foraging strategies (including agility and speed).

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Foraging ecology and organisation of a desert bat fauna

Australian Journal of Zoology ◽

10.1071/zo01029 ◽

2002 ◽

Vol 50 (5) ◽

pp. 529 ◽

Cited By ~ 18

Author(s):

N. L. McKenzie ◽

A. N. Start ◽

R. D. Bullen

Keyword(s):

Foraging Ecology ◽

Foraging Strategy ◽

The Other ◽

Design Parameters ◽

Microhabitat Use ◽

Flight Performance ◽

Sandy Desert ◽

Stability And Control ◽

Family Level ◽

And Control

Airframe design parameters related to flight performance, stability and control had tight, functionally appropriate relationships with the foraging niches and echolocation parameters of nine species comprising the bat fauna of the Little Sandy Desert, Australia. The airframe parameters segregated into two near-independent groups, one related to microhabitat use, the other to foraging strategy. The structure of the desert's bat fauna is displayed in these terms, and its organisation is compared with the faunas of surrounding regions. A diversity–productivity model of faunal structure is revealed, with an organisation that conforms with the 'specialisation' hypothesis. Clear family-level relationships between phylogeny and foraging ecology imply that ecological specialisations occurred early in the evolution of bats.

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Classification of a 3-RER Parallel Manipulator Based on the Type and Number of Operation Modes

Journal of Mechanisms and Robotics ◽

10.1115/1.4048262 ◽

2020 ◽

pp. 1-17

Author(s):

Xianwen Kong

Keyword(s):

Parallel Manipulator ◽

Operation Mode ◽

Mode Analysis ◽

Type Number ◽

Systematic Classification ◽

Operation Modes ◽

Solid Foundation ◽

And Control ◽

The Impact

Abstract The type/number of operation modes of a parallel manipulator (PM) may vary with the link parameters of the PM. This paper presents a systematic classification of a 3-RER PM based on the type/number of operation modes. The 3-RER PM was proposed as a 4-DOF (degree-of-freedom) 3T1R PM in the literature. Using the proposed method, the classification of a PM based on the type/number of operation modes can be carried out in four steps, including formulation of constraint equations of the PM, preliminary classification of the PM using Gröbner Cover, operation mode analysis of all the types of PMs using primary decomposition of ideals, and identification redundant types of PMs. Classification of the 3-RER PM shows that it has 19 types. Besides the two 4-DOF 3T1R operation modes, different types of 3-RER PMs may have up to two more 3-DOF or other types of 4- DOF operation modes. This work is the first systematic study on the impact of link parameters on the operation modes of the 3-RER PM and provide a solid foundation for further research on the design and control of 3-RER PMs and other multi-mode (or reconfigurable) PMs.

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The ecological and evolutionary interface of hummingbird flight physiology

Journal of Experimental Biology ◽

10.1242/jeb.205.16.2325 ◽

2002 ◽

Vol 205 (16) ◽

pp. 2325-2336 ◽

Cited By ~ 11

Author(s):

Douglas L. Altshuler ◽

Robert Dudley

Keyword(s):

Competitive Ability ◽

Tail Length ◽

Interspecific Variation ◽

Foraging Strategies ◽

Flight Performance ◽

Evolutionary Time ◽

Floral Nectar ◽

Selective Agents ◽

Stroke Amplitude ◽

Related Morphology

SUMMARYThe hovering ability, rapidity of maneuvers and upregulated aerobic capacity of hummingbirds have long attracted the interest of flight biologists. The range of intra- and interspecific variation in flight performance among hummingbirds, however, is equally impressive. A dominant theme in hummingbird evolution is progressive invasion of higher-elevation habitats. Hypobaric challenge is met behaviorally through compensatory changes in wingbeat kinematics, particularly in stroke amplitude. Over evolutionary time scales, montane colonization is associated with increases in body mass and relative wing area. Hovering ability has been well-studied in several North American hummingbird taxa, yet the broad range of interspecific variation in hummingbird axial and appendicular anatomy remains to be assessed mechanistically. Such varied features as tail length, molt condition and substantial weight change due to lipid-loading can dramatically alter various features of the flight envelope. Compared with our present knowledge of hovering performance in hummingbirds, the mechanics of forward flight and maneuvers is not well understood.Relationships among flight-related morphology, competitive ability and foraging behavior have been the focus of numerous studies on tropical and temperate hummingbirds. Ecologists have hypothesized that the primary selective agents on hummingbird flight-related morphology are the behaviors involved in floral nectar consumption. However, flight behaviors involved in foraging for insects may also influence the evolution of wing size and shape. Several comparisons of hummingbird communities across elevational gradients suggest that foraging strategies and competitive interactions within and among species vary systematically across elevations as the costs of flight change with body size and wing shape.

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