Walton P, Ruxton GD, Monaghan P
Division of Environmental & Evolutionary Biology, University of Glasgow
Anim Behav. 1998 Jul;56(1):165-74. doi: 10.1006/anbe.1998.0759.
Behavioural studies of diving birds have reported that the ratio of dive duration to the duration of the subsequent period on the surface displays a characteristic relation to dive duration. For short dives, the dive to surface ratio increases with dive duration, whereafter the relation peaks, and for longer dives decreases with increasing dive duration. Such a relationship is not a general prediction of existing marginal value models which have been used to predict optimal diving behaviour. This may be because the smooth curve used to describe the oxygen gain rate of individuals after surfacing is not a good reflection of the respiratory physiology of birds. Here we argue that on physiological grounds, the oxygen gain curve for avian divers will not be smooth, but will have two distinct regions (representing oxygen recovery in the respiratory tract, and in haemoglobin and myoglobin, respectively). Modifying two of the classical diving models by incorporating such a kinked curve causes them to predict the humped relationship between dive to surface ratio and dive duration under many circumstances. We also present data on the duration of dives and surface periods from three species of diving seabirds: the shag, Phalacrocorax aristotelis, the black guillemot, Cepphus grylle and the common guillemot, Uria aalge. All three species showed a humped relationship for dive to surface ratio as a function of dive duration. In line with the predictions of our model, when oxygen stores on surfacing were greatly depleted, the dive to surface ratio peaked at short dive durations. Copyright 1998 The Association for the Study of Animal Behaviour.
对潜水鸟类的行为研究表明，潜水持续时间与随后在水面停留时间的比值与潜水持续时间呈现出一种特征性关系。对于短时间潜水，潜水与水面停留时间的比值随潜水持续时间增加，此后该关系达到峰值，而对于较长时间潜水，该比值则随潜水持续时间增加而降低。这种关系并非用于预测最佳潜水行为的现有边际价值模型的普遍预测结果。这可能是因为用于描述个体浮出水面后氧气获取率的平滑曲线并不能很好地反映鸟类的呼吸生理学。在此我们认为，基于生理学原因，鸟类潜水者的氧气获取曲线不会是平滑的，而是会有两个不同区域（分别代表呼吸道以及血红蛋白和肌红蛋白中的氧气恢复）。通过纳入这样一条有拐点的曲线对两个经典潜水模型进行修正，会使它们在许多情况下预测出潜水与水面停留时间比值和潜水持续时间之间的驼峰关系。我们还展示了三种潜水海鸟（鸬鹚，即岩鸬鹚；黑海雀；以及普通海雀）的潜水和水面停留时间的数据。所有这三个物种的潜水与水面停留时间比值都呈现出作为潜水持续时间函数的驼峰关系。与我们模型的预测一致，当浮出水面时的氧气储备大幅耗尽时，潜水与水面停留时间比值在短潜水持续时间时达到峰值。版权所有1998年动物行为研究协会。
