Timing is an essential parameter influencing many behaviours. A previous study demonstrated a high sensitivity of a phocid, the harbour seal (Phoca vitulina), in discriminating time intervals. In the present study, we compared the harbour seal’s timing abilities with the timing abilities of an otariid, the South African fur seal (Arctocephalus pusillus pusillus). This comparison seemed essential as phocids and otariids differ in many respects and might, thus, also differ regarding their timing abilities. We determined time difference thresholds for sub- and suprasecond time intervals marked by a white circle on a black background displayed for a specific time interval on a monitor using a staircase method. Contrary to our expectation, the timing abilities of the fur seal and the harbour seal were comparable. Over a broad range of time intervals, 0.8–7 s in the fur seal and 0.8–30 s in the harbour seal, the difference thresholds followed Weber’s law. In this range, both animals could discriminate time intervals differing only by 12 % and 14 % on average. Timing might, thus be a fundamental cue for pinnipeds in general to be used in various contexts, thereby complementing information provided by classical sensory systems. Future studies will help to clarify if timing is indeed involved in foraging decisions or the estimation of travel speed or distance.

中文翻译：

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斑海豹 (Phoca vitulina) 和南非毛皮海豹 (Arctocephalus pusillus pusillus) 在亚秒和超秒时间间隔内的视觉计时能力。


时间是影响许多行为的重要参数。先前的一项研究表明，斑海豹 ( Phoca vitulina ) 在辨别时间间隔方面具有很高的敏感性。在本研究中，我们将斑海豹的计时能力与南非毛皮海豹（ Arctocephalus pusillus pusillus ）的计时能力进行了比较。这种比较似乎很重要，因为 phocids 和 otariids 在许多方面都不同，因此它们的计时能力也可能不同。我们确定了亚秒和超秒时间间隔的时间差阈值，该阈值用黑色背景上的白色圆圈标记，使用阶梯法在监视器上显示特定时间间隔。与我们的预期相反，海狗和斑海豹的计时能力相当。在较宽的时间间隔范围内，海豹为 0.8-7 秒，斑海豹为 0.8-30 秒，阈值差异遵循韦伯定律。在此范围内，两只动物能够区分的时间间隔平均仅相差 12% 和 14%。因此，时间可能是鳍足类动物在各种环境中使用的基本线索，从而补充了经典感觉系统提供的信息。未来的研究将有助于澄清时间是否确实与觅食决策或行进速度或距离的估计有关。