Table 1.

Rates of oxygen consumption, carbon dioxide production and the respiratory exchange ratio (RER) during flights across a range of speeds

O2 (ml O2 kg-1 s-1)CO2 (ml CO2 kg-1 s-1) RER (CO2/O2)
Flight speed (m s-1)BudgerigarCockatielBudgerigarCockatielBudgerigarCockatiel
511.9±0.47.7±0.16.9±0.20.91±0.02
610.8±0.37.2±0.17.8±0.35.5±0.20.75±0.020.76±0.07
89.3±0.25.4±0.27.0±0.14.0±0.20.77±0.040.74±0.05
109.1±0.25.1±0.26.9±0.13.8±0.20.75±0.040.75±0.07
129.6±0.26.3±0.27.7±0.24.6±0.20.80±0.050.72±0.05
1410.9±0.96.6±0.39.2±1.34.6±0.10.88±0.010.71±0.04
158.3±0.36.8±0.90.81±0.11
  • Budgerigars (N=4, body mass=36.7±2.1 g); cockatiels (N=3, body mass=80.5±5.6 g).