Hambly C, Harper E J, Speakman J R
Department of Zoology, Tillydrone Avenue, University of Aberdeen, Aberdeen, AB24 3TZ Scotland, UK.
J Comp Physiol B. 2002 Aug;172(6):529-39. doi: 10.1007/s00360-002-0279-7. Epub 2002 Jul 19.
On three separate occasions, five zebra finches ( Taenopygia guttata) were injected intraperitoneally with 0.2 ml 0.29 M NaH(13)CO(3)solution and placed immediately into respirometry chambers to explore the link between (13)C elimination and both O(2) consumption (VO(2)) and CO(2) production (VCO(2)). Isotope elimination was best modelled by a mono-exponential decay. The elimination rate (k(c)) of the (13)C isotope in breath was compared to VO(2) (ml O(2)/min) and VCO(2) (ml CO(2)/min) over sequential 5-min time intervals following administration of the isotope. Elimination rates measured 15-20 min after injection gave the closest relationships to VO(2) ( r(2) =0.82) and VCO(2) ( r(2)=0.63). Adding the bicarbonate pool size (N(c)) into the prediction did not improve the fit. A second group of birds ( n=11) were flown for 2 min (three times in ten birds and twice in one) between 15 min and 20 min following an injection of 0.2 ml of the same NaH(13)CO(3) solution. Breath samples, collected before and after flight, were used to calculate k(c) over the flight period, which was converted to VO(2) and VCO(2) using the equation generated in the validation experiment for the corresponding time period. The energy expenditure (watts) during flight was calculated from these values using the average RQ measured during flight of 0.79. The average flight cost measured using the bicarbonate technique was 2.24+/-0.11 W (mean+/-SE). This average flight cost did not differ significantly from predictions generated by an allometric equation formulated by Masman and Klaassen (1987 Auk 104:603-616). It was however substantially higher than the predictions based on the aerodynamic model of Pennycuick (1989 Oxford University Press), which assumes an efficiency of 0.23 for flight. The flight efficiency in these birds was 0.11 using this model. Flight cost was not related to within-individual variation [general linear model (GLM) F(1,31)=1.16, P=0.29] or across-individual variations in body mass (GLM F(1,31)=0.26, P=0.61), wingspan (regression F(1,10)=0.01, P=0.94) or wing loading (regression F(1, 31)=0.001, P=0.99) in this sample of birds.
在三个不同的时间段，分别给五只斑胸草雀（Taenopygia guttata）腹腔注射0.2毫升0.29 M的NaH(13)CO(3)溶液，并立即将它们放入呼吸测量室，以探究(13)C消除与氧气消耗（VO(2)）和二氧化碳产生（VCO(2)）之间的联系。同位素消除最好用单指数衰减模型来描述。在注射同位素后的连续5分钟时间间隔内，将呼出气体中(13)C同位素的消除率（k(c)）与VO(2)（毫升O(2)/分钟）和VCO(2)（毫升CO(2)/分钟）进行比较。注射后15 - 20分钟测得的消除率与VO(2)（r(2)=0.82）和VCO(2)（r(2)=0.63）的关系最为密切。将碳酸氢盐池大小（N(c)）纳入预测并没有改善拟合效果。第二组鸟（n = 11）在注射0.2毫升相同的NaH(13)CO(3)溶液后15分钟至20分钟之间飞行2分钟（十只鸟飞行三次，一只鸟飞行两次）。飞行前后采集的呼吸样本用于计算飞行期间的k(c)，并使用验证实验中对应时间段生成的方程将其转换为VO(2)和VCO(2)。根据飞行期间测得的平均呼吸商0.79，从这些值计算出飞行期间的能量消耗（瓦特）。使用碳酸氢盐技术测得的平均飞行成本为2.24±0.11瓦（平均值±标准误）。这个平均飞行成本与Masman和Klaassen（1987年，《奥克》104:603 - 616）制定的异速生长方程预测值没有显著差异。然而，它远高于基于Pennycuick（1989年，牛津大学出版社）的空气动力学模型的预测值，该模型假设飞行效率为0.
