Maximum metabolic rate, relative lift, wingbeat frequency and stroke amplitude during tethered flight in the adult locust Locusta migratoria

Axon counts have been made from electron micrographs of the hindwing sensory nerves 1C 1 and 1D 2 in the adult locust and during development. In the adult, nerve 1C 1 contains approximately 1000 axons. At least a quarter have diameters over 1 µm, more than forty 5-12 µm. Seventy large axons come from the tegula, the rest from the wing. Nerve 1D 2 contains 400 axons, 64 between 1 µm and 6.5 µm in diameter. Large axons are assumed to come from the wing base chordotonal organ and stretch receptor, the remainder from thoracic hair fields. During development, axon numbers in nerve 1C 1 rapidly increase at the 4th instar, corresponding to the development of the wing bud. By the final moult there are over 2000 axons, half of which disappear in the two weeks after fledging. In nerve 1D 2 the stretch receptor and chordotonal axons are present from the first instar. Small fibres increase in number mainly in the 5th instar. In contrast to nerve 1C 1 there is no change in numbers after fledging. In both nerves, diameters and glial wrapping of axons increase in the two weeks after fledging, although the changes are more marked in nerve 1C 1 . The large input from the tegula suggests an important rôle in the phasic control of flight. The post-fledging increase in diameter and glial wrappings of tegula axons may influence the increase in wingbeat frequency with age.

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Recovery of the flight system following ablation of the tegulae in immature adult locusts

Journal of Experimental Biology ◽

10.1242/jeb.199.6.1395 ◽

1996 ◽

Vol 199 (6) ◽

pp. 1395-1403 ◽

Cited By ~ 3

Author(s):

C Gee ◽

R Robertson

Keyword(s):

Locusta Migratoria ◽

Motor Pattern ◽

Recovery Period ◽

Wingbeat Frequency ◽

Mature Adult ◽

Flight System ◽

Mature Adults ◽

Locust Flight ◽

Adult Locust ◽

The Individual

The capacity of the flight system to recover from ablation of the tegulae was studied in immature adult Locusta migratoria and compared with recovery in mature adults. We ablated the hindwing tegulae or all tegulae in adult locusts either 1 day after the imaginal moult (immature locusts) or 2 weeks after the imaginal moult (mature locusts). We monitored recovery throughout the recovery period by using a stroboscope to measure the wingbeat frequency of tethered locusts. In addition, we measured other parameters of the flight motor pattern using electromyographic electrodes implanted into recovered locusts. Both methods of monitoring recovery yielded the same results. There was no reduction, during adult maturation, in the capacity of the locust flight system to recover from the loss of these proprioceptors. Plasticity of the locust flight system was therefore maintained in the mature adult locust. This suggests that the flight system is not fixed and simply implemented when the locust reaches adulthood, but that the circuitry can be remodelled throughout the animal's life to produce behaviour adapted to the needs and constraints of the individual.

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Analytical methods matter too: Establishing a framework for estimating maximum metabolic rate for fishes

Ecology and Evolution ◽

10.1002/ece3.7732 ◽

2021 ◽

Author(s):

Tanya S. Prinzing ◽

Yangfan Zhang ◽

Nicholas C. Wegner ◽

Nicholas K. Dulvy

Keyword(s):

Metabolic Rate ◽

Analytical Methods ◽

Maximum Metabolic Rate

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Changes in body temperature influence the scaling of and aerobic scope in mammals

Biology Letters ◽

10.1098/rsbl.2006.0576 ◽

2006 ◽

Vol 3 (1) ◽

pp. 100-103 ◽

Cited By ~ 21

Author(s):

James F Gillooly ◽

Andrew P Allen

Keyword(s):

Body Size ◽

Metabolic Rate ◽

Size Dependence ◽

Maximal Activity ◽

Scaling Exponent ◽

Temperature Influence ◽

Aerobic Scope ◽

Metabolic Scope ◽

Single Power ◽

Maximum Metabolic Rate

Debate on the mechanism(s) responsible for the scaling of metabolic rate with body size in mammals has focused on why the maximum metabolic rate ( ) appears to scale more steeply with body size than the basal metabolic rate (BMR). Consequently, metabolic scope, defined as /BMR, systematically increases with body size. These observations have led some to suggest that and BMR are controlled by fundamentally different processes, and to discount the generality of models that predict a single power-law scaling exponent for the size dependence of the metabolic rate. We present a model that predicts a steeper size dependence for than BMR based on the observation that changes in muscle temperature from rest to maximal activity are greater in larger mammals. Empirical data support the model's prediction. This model thus provides a potential theoretical and mechanistic link between BMR and .

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Scaling of Basal and Maximum Metabolic Rate in Rodents and the Aerobic Capacity Model for the Evolution of Endothermy

Physiological Zoology ◽

10.1086/physzool.65.5.30158550 ◽

1992 ◽

Vol 65 (5) ◽

pp. 921-932 ◽

Cited By ~ 53

Author(s):

Francisco Bozinovic

Keyword(s):

Metabolic Rate ◽

Aerobic Capacity ◽

Capacity Model ◽

Maximum Metabolic Rate

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GENETIC VARIABILITY OF FLIGHT METABOLISM IN DROSOPHILA MELANOGASTER. I. CHARACTERIZATION OF POWER OUTPUT DURING TETHERED FLIGHT

Genetics ◽

10.1093/genetics/98.3.549 ◽

1981 ◽

Vol 98 (3) ◽

pp. 549-564

Author(s):

James W Curtsinger ◽

Cathy C Laurie-Ahlberg

Keyword(s):

Drosophila Melanogaster ◽

Power Output ◽

Beat Frequency ◽

Wing Beat ◽

Tethered Flight ◽

Flight Metabolism ◽

Flight Parameters ◽

Wing Stroke ◽

Stroke Amplitude

ABSTRACT The mechanical power imparted to the wings during tethered flight of Drosophila melanogaster is estimated from wing-beat frequency, wing-stroke amplitude and various aspects of wing morphology by applying the steady-state aerodynamics model of insect flight developed by Weis-Fogh (1972, 1973). Wing-beat frequency, the major determinant of power output, is highly correlated with the rate of oxygen consumption. Estimates of power generated during flight should closely reflect rates of ATP production in the flight muscles, since flies do not acquire an oxygen debt or accumulate ATP during flight. In an experiment using 21 chromosome 2 substitution lines, lines were a significant source of variation for all flight parameters measured. Broadsense heritabilities ranged from 0.16 for wing-stroke amplitude to 0.44 for inertial power. The variation among lines is not explained by variation in total body size (i.e., live weight). Line differences in flight parameters are robust with respect to age, ambient temperature and duration of flight. These results indicate that characterization of the power output during tethered flight will provide a sensitive experimental system for detecting the physiological effects of variation in the structure or quantity of the enzymes involved in flight metabolism.

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Do method and species lifestyle affect measures of maximum metabolic rate in fishes?

Journal of Fish Biology ◽

10.1111/jfb.13195 ◽

2016 ◽

Vol 90 (3) ◽

pp. 1037-1046 ◽

Cited By ~ 35

Author(s):

S. S. Killen ◽

T. Norin ◽

L. G. Halsey

Keyword(s):

Metabolic Rate ◽

Maximum Metabolic Rate

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Kinematics Measurement and Power Requirements of Fruitflies at Various Flight Speeds

Energies ◽

10.3390/en13164271 ◽

2020 ◽

Vol 13 (16) ◽

pp. 4271

Author(s):

Hao Jie Zhu ◽

Mao Sun

Keyword(s):

The Body ◽

Flight Speed ◽

Specific Power ◽

Flight Performance ◽

Wingbeat Frequency ◽

Body Angle ◽

Flying Insects ◽

Speed Range ◽

Full Speed ◽

Stroke Amplitude

Energy expenditure is a critical characteristic in evaluating the flight performance of flying insects. To investigate how the energy cost of small-sized insects varies with flight speed, we measured the detailed wing and body kinematics in the full speed range of fruitflies and computed the aerodynamic forces and power requirements of the flies. As flight speed increases, the body angle decreases and the stroke plane angle increases; the wingbeat frequency only changes slightly; the geometrical angle of attack in the middle upstroke increases; the stroke amplitude first decreases and then increases. The mechanical power of the fruitflies at all flight speeds is dominated by aerodynamic power (inertial power is very small), and the magnitude of aerodynamic power in upstroke increases significantly at high flight speeds due to the increase of the drag and the flapping velocity of the wing. The specific power (power required for flight divided by insect weigh) changes little when the advance ratio is below about 0.45 and afterwards increases sharply. That is, the specific power varies with flight speed according to a J-shaped curve, unlike those of aircrafts, birds and large-sized insects which vary with flight speed according to a U-shaped curve.

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Integrating morphology and kinematics in the scaling of hummingbird hovering metabolic rate and efficiency

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2017.2011 ◽

2018 ◽

Vol 285 (1873) ◽

pp. 20172011 ◽

Cited By ~ 4

Author(s):

Derrick J. E. Groom ◽

M. Cecilia B. Toledo ◽

Donald R. Powers ◽

Bret W. Tobalske ◽

Kenneth C. Welch

Keyword(s):

Body Size ◽

Metabolic Rate ◽

Wing Size ◽

Wing Morphology ◽

Morphological Adaptation ◽

Wingbeat Frequency ◽

Cycle Frequency ◽

Scaling Relationship ◽

Metabolic Costs ◽

The Cost

Wing kinematics and morphology are influential upon the aerodynamics of flight. However, there is a lack of studies linking these variables to metabolic costs, particularly in the context of morphological adaptation to body size. Furthermore, the conversion efficiency from chemical energy into movement by the muscles (mechanochemical efficiency) scales with mass in terrestrial quadrupeds, but this scaling relationship has not been demonstrated within flying vertebrates. Positive scaling of efficiency with body size may reduce the metabolic costs of flight for relatively larger species. Here, we assembled a dataset of morphological, kinematic, and metabolic data on hovering hummingbirds to explore the influence of wing morphology, efficiency, and mass on hovering metabolic rate (HMR). We hypothesize that HMR would decline with increasing wing size, after accounting for mass. Furthermore, we hypothesize that efficiency will increase with mass, similarly to other forms of locomotion. We do not find a relationship between relative wing size and HMR, and instead find that the cost of each wingbeat increases hyperallometrically while wingbeat frequency declines with increasing mass. This suggests that increasing wing size is metabolically favourable over cycle frequency with increasing mass. Further benefits are offered to larger hummingbirds owing to the positive scaling of efficiency.

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Flight muscle power increases with strain amplitude and decreases with cycle frequency in zebra finches (Taeniopygia guttata)

Journal of Experimental Biology ◽

10.1242/jeb.225839 ◽

2020 ◽

Vol 223 (21) ◽

pp. jeb225839 ◽

Cited By ~ 1

Author(s):

Joseph W. Bahlman ◽

Vikram B. Baliga ◽

Douglas L. Altshuler

Keyword(s):

Strain Amplitude ◽

Power Output ◽

Muscle Power ◽

Aerodynamic Force ◽

Taeniopygia Guttata ◽

Zebra Finches ◽

Kinematic Parameters ◽

Wingbeat Frequency ◽

Cycle Frequency ◽

Stroke Amplitude

ABSTRACTBirds that use high flapping frequencies can modulate aerodynamic force by varying wing velocity, which is primarily a function of stroke amplitude and wingbeat frequency. Previous measurements from zebra finches (Taeniopygia guttata) flying across a range of speeds in a wind tunnel demonstrate that although the birds modulated both wingbeat kinematic parameters, they exhibited greater changes in stroke amplitude. These two kinematic parameters contribute equally to aerodynamic force, so the preference for modulating amplitude over frequency may instead derive from limitations of muscle physiology at high frequency. We tested this hypothesis by developing a novel in situ work loop approach to measure muscle force and power output from the whole pectoralis major of zebra finches. This method allowed for multiple measurements over several hours without significant degradation in muscle power. We explored the parameter space of stimulus, strain amplitude and cycle frequencies measured previously from zebra finches, which revealed overall high net power output of the muscle, despite substantial levels of counter-productive power during muscle lengthening. We directly compared how changes to muscle shortening velocity via strain amplitude and cycle frequency affected muscle power. Increases in strain amplitude led to increased power output during shortening with little to no change in power output during lengthening. In contrast, increases in cycle frequency did not lead to increased power during shortening but instead increased counter-productive power during lengthening. These results demonstrate why at high wingbeat frequency, increasing wing stroke amplitude could be a more effective mechanism to cope with increased aerodynamic demands.

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