Respiratory and Cardiovascular Responses of the Pigeon to Sustained, Level Flight in a Wind-Tunnel

摘要: 1. Five pigeons were trained to fly in a boundary-layer wind-tunnel at velocity of 10 m s−1 for least min, and number respiratory cardiovascular variables recorded. For comparison, heart rate, frequency E.M.G. from the pectoralis major muscles also recorded, using radio-telemetry, free-flying pigeons. 2. 2. flights wind tunnel there immediate increases rate upon take-off; these continued increase during flight, eventually becoming on average 411 breaths min−1 (20 × resting) 670 beats (6 respectively. There was 1:1 relationship between ventilation wing beat. Oxygen uptake carbon dioxide production reached their highest values 12.5 14.4 resting respectively within 1 min take-off then declined steady levels 200 ml kg−1 S.T.P.D. (10 184 (10.7 4 after take-off. If allowances are made weightand drag V OO2 mask tubes, stable 12% higher than would occur an unloaded bird. Body temperature rose steadily take-off, reaching value 43.3°C, which 2°C above resting, 6 flight. 1.8 rise - v content difference little change cardiac stroke volume so that factor transporting extra O2 active muscles. Respiratory quotient 0.85 rest 0.99, 30 s take off, fell 0.92 7 Blood lactate 59.8 mg% (6.5 its value). 3. 3. Comparisons with birds indicated pattern flight somewhat abnormal, especially beginning this may account being start declining as progressed. 4. 4. Upon landing, V· O1 CO2 body began fall immediately, 2 had returned ‘tunnel on’ values. increased landing decline closely matched temperature. R.Q. unity immediately removed excess metabolic production, below retained, presumably maintain acid/base balance metabolism lactic acid.