NEUROMUSCULAR CONTROL AND KINEMATICS OF INTERMITTENT FLIGHT IN BUDGERIGARS (MELOPSITTACUS UNDULATUS)

Kinematic and electromyographic data were collected from budgerigars (parakeets), Melopsittacus undulatus, flying at different speeds in a variable-speed wind tunnel. Birds exhibited flap-gliding at low speeds and flap-bounding at high speeds. The percentage of time spent flapping generally decreased at intermediate speeds. These behavior patterns are consistent with minimizing energy expenditure according to aerodynamic theory. During intermittent glides, the pectoralis exhibited an isometric contraction while the supracoracoideus was inactive. During bounds, both muscles were inactive. Contrary to earlier work, our studies indicate that budgerigars do not exhibit simultaneous twitch contractions of the pectoralis during each wingbeat, but rather generate typical multiple-spike electromyographic bursts that represent motor unit action potential trains or asynchronous twitch contractions from different motor units. The relative intensity of electromyographic bursts from the primary flight muscles increased with flight speed. This may indicate an increase in force production. Our observations of isometric contractions during glides, along with patterns of variation in muscle activity and wingbeat frequency, do not support the hypothesis that small birds such as the budgerigar use flap-bounding as their only means of reducing power output during flight.

[1]  J. Basmajian.  Muscles Alive—their functions revealed by electromyography , 1963 .

[2]  G. E. Goslow,et al.  The functional anatomy of the shoulder in the European starling (Sturnus vulgaris) , 1991, Journal of morphology.

[3]  A. J. Ward-Smith.  Aerodynamic and energetic considerations relating to undulating and bounding flight in birds , 1984 .

[4]  K. Dial.  Activity patterns of the wing muscles of the pigeon (Columba livia) during different modes of flight , 1992 .

[5]  V. Tucker,et al.  Bird Metabolism During Flight: Evaluation of a Theory , 1973 .

[6]  C. Pennycuick.  Power requirements for horizontal flight in the pigeon Columba livia , 1968 .

[7]  Jeremy M. V. Rayner,et al.  Bounding and undulating flight in birds , 1985 .

[8]  Benjamin W. C. Rosser,et al.  The avian pectoralis : histochemical characterization and distribution of muscle fiber types , 1986 .

[9]  R. Burke.  Motor Units: Anatomy, Physiology, and Functional Organization , 1981 .

[10]  A. Biewener,et al.  PECTORALIS MUSCLE FORCE AND POWER OUTPUT DURING DIFFERENT MODES OF FLIGHT IN PIGEONS (COLUMBA LIVIA) , 1993 .

[11]  K. Dial,et al.  AVIAN FORELIMB MUSCLES AND NONSTEADY FLIGHT: CAN BIRDS FLY WITHOUT USING THE MUSCLES IN THEIR WINGS? , 1992 .

[12]  John J. Videler,et al.  Field Measurements of Hanging Flight Aerodynamics in the Kestrel Falco Tinnunculus , 1991 .

[13]  Electrical activity from the pectoral muscle of a flying bird, the budgerigar☆ , 1970 .

[14]  G. E. Goslow,et al.  Structure and neural control of the pectoralis in pigeons: Implications for flight mechanics , 1987, The Anatomical record.

[15]  Thomas A. McMahon,et al.  Muscles, Reflexes, and Locomotion , 1984 .

[16]  C. Pennycuick.  A wind tunnel study of gliding flight in the pigeon Columba livia , 1968 .

[17]  J. Rayner.  A New Approach to Animal Flight Mechanics , 1979 .

[18]  E. Kaplan.  Muscles Alive. Their Functions Revealed by Electromyography. J. V. Basmajian. Baltimore, The Williams and Wilkins Co., 1962. $8.50 , 1962 .

[19]  John E. R. Staddon,et al.  Optima for animals , 1982 .

[20]  G. E. Goslow,et al.  A functional analysis of the primary upstroke and downstroke muscles in the domestic pigeon (Columba livia) during flight. , 1988, The Journal of experimental biology.

[21]  Colin J Pennycuick,et al.  Bird flight performance: a practical calculation manual , 1992 .

[22]  Colin J Pennycuick,et al.  Predicting Wingbeat Frequency and Wavelength of Birds , 1990 .

[23]  V. Tucker.  Respiratory Exchange and Evaporative Water Loss in the Flying Budgerigar , 1968 .

[24]  A. J. Ward-Smith,et al.  Analysis of the aerodynamic performance of birds during bounding flight , 1984 .

[25]  G. Loeb,et al.  Electromyography for Experimentalists , 1986 .

[26]  C. J. Pennycuick,et al.  Chapter 1 – MECHANICS OF FLIGHT , 1975 .

[27]  J. Larochelle,et al.  The metabolic cost of flight in unrestrained birds. , 1978, The Journal of experimental biology.