Duke University Marine Lab, Beaufort, NC 28516, USA.
Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109, USA.
J Exp Biol. 2022 Feb 15;225(4). doi: 10.1242/jeb.243121. Epub 2022 Feb 24.
Estimates of the energetic costs of locomotion (COL) at different activity levels are necessary to answer fundamental eco-physiological questions and to understand the impacts of anthropogenic disturbance to marine mammals. We combined estimates of energetic costs derived from breath-by-breath respirometry with measurements of overall dynamic body acceleration (ODBA) from biologging tags to validate ODBA as a proxy for COL in trained common bottlenose dolphins (Tursiops truncatus). We measured resting metabolic rate (RMR); mean individual RMR was 0.71-1.42 times that of a similarly sized terrestrial mammal and agreed with past measurements that used breath-by-breath and flow-through respirometry. We also measured energy expenditure during submerged swim trials, at primarily moderate exercise levels. We subtracted RMR to obtain COL, and normalized COL by body size to incorporate individual swimming efficiencies. We found both mass-specific energy expenditure and mass-specific COL were linearly related with ODBA. Measurements of activity level and cost of transport (the energy required to move a given distance) improve understanding of the COL in marine mammals. The strength of the correlation between ODBA and COL varied among individuals, but the overall relationship can be used at a broad scale to estimate the energetic costs of disturbance and daily locomotion costs to build energy budgets, and investigate the costs of diving in free-ranging animals where bio-logging data are available. We propose that a similar approach could be applied to other cetacean species.
估计不同活动水平下的运动能量成本（COL）对于回答基本的生态生理问题和理解人为干扰对海洋哺乳动物的影响是必要的。我们将呼吸式气体测量法得出的能量成本估计值与生物遥测标签测量的总体动态身体加速度（ODBA）相结合，验证了 ODBA 可作为经过训练的宽吻海豚（Tursiops truncatus）COL 的替代指标。我们测量了休息代谢率（RMR）；个体平均 RMR 是类似大小的陆地哺乳动物的 0.71-1.42 倍，与使用呼吸式和流通式气体测量法的以往测量结果一致。我们还在主要为中等运动水平的潜水游泳试验中测量了能量消耗。我们从 RMR 中减去 COL，并通过体型对 COL 进行归一化，以纳入个体的游泳效率。我们发现，比能量消耗和比 COL 与 ODBA 均呈线性关系。对活动水平和运输成本（移动给定距离所需的能量）的测量提高了对海洋哺乳动物 COL 的理解。ODBA 和 COL 之间的相关性在个体之间存在差异，但总体关系可以在广泛的范围内用于估计干扰的能量成本和每日运动成本，以建立能量预算，并研究具有生物遥测数据的自由放养动物的潜水成本。我们建议可以将类似的方法应用于其他鲸目动物。
