Power Consumption of Flight at Different Speeds in Chinese Bulbuls, Pycnonotus sinensis: Estimated from Aerodynamics

• Main Authors: Huang, Shian-Lin, 黃祥麟
• Other Authors: Chou, Lien-Shiang; Sue, Chin-Chia
• Format: Others
• Language: zh-TW
• Published: 1996
• Online Access: http://ndltd.ncl.edu.tw/handle/51780471025703822558

碩士 === 國立臺灣大學 === 動物學系 === 84 === The flight speeds and kinematic parameters of three Chinese bulbuls (Pycnonotus sinensis) (No. 1, 2, 3) were recorded. Using these data, and their morpholigical parameters, I estimated the power consumptions of these three birds at flight with the use of aerodynamic theory. The wingbeat frequency and amplitude did not change with flight speeds and among individuals. The body inclination angle decreased with the increasing flight speed and there existed a simple linear relationship. I suggest that the Chinese bulbuls may change their flight speeds simply by changing their body inclination angle. When flying at slow speed, the induced power of the bird was about 80% of its mechanical power requirements. The profile and parasite power were about 5% of mechanical power. At fast flight, the induced power was about 50% of its mechanical power requirements and the proportion of profile and parasite power in mechanical power were about 30%. As the induced power is concerned with the life generation and the profile and parasite power is concerned with the drag, I suggested that at slow flight most of the power expenditure is used to lift generation. But at high speed, 50% of its power expenditure is used to lift generation and another 28% to 30% is used to overcome the drag. The inertial power was 15% to 17% of its mechanical power at slow flight and 22.6% to 27% at fast flight. I suggest that the inertial power should not be ignored in the calculation of power consumption of flight. If the mechanical efficiency of flight muscle is assumed between 0.08 and 0.23, the possible range of flight metabolic rate could be 7.12 to 18.40 times of basal metabolic rate at slow flight and 4.57 to 11.08 times of BMR at fast flight.