The dynamics and energetics of hunting in the cheetah

猎豹可以以每小时65英里的速度冲刺，这使它成为迄今为止速度最快的陆地动物-精英赛狗和赛马（以及动物园里追逐诱饵的猎豹）只能以每小时40英里的速度奔跑。猎豹的机动性也很强，即使是最敏捷的猎物也能被它们抓住。但是猎豹是怎么做到的呢？目前我们还不知道。被广泛引用的“猎豹最高速度”来自1965年一只猎豹的三次跑步。为了找到答案，我们需要测量猎豹在野外狩猎时的表现--这是唯一一次达到峰值速度和机动性的时候。然而，虽然猎豹几乎每天都在狩猎，但很难直接观察到狩猎。我们计划为野生猎豹配备配备我们专门为此类工作开发的独特技术的项圈。每个项圈都包含一个特殊的高精度全球定位系统，以确定位置和速度沿着与加速度传感器，微型陀螺仪，指南针和一个微型低功耗计算机。传感器可以检测猎豹的确切脚步模式-有多少步幅以及每只脚何时在地面上。项圈监控猎豹的位置和正在做的事情-休息，行走，最重要的是，狩猎，只有当猎豹快速移动时才收集详细信息（每秒记录数据高达300次）。从数据中，我们可以重建猎豹在狩猎过程中的确切运动。在其他时候，会记录定期的位置更新和行为，并且集成太阳能电池板会为电池充电。项圈的数据被存储起来，以便以后通过一个完整的无线电链接下载。我们的目标是使用一个高分辨率的高速摄像机从地面和空中拍摄猎豹狩猎，该摄像机安装在一个自动指向GPS导出位置的支架上。项圈通过无线电连接告诉坐骑相机指向哪里，相机跟踪猎豹的运动（我们实际上也把相机对准猎豹的前方，以便看到猎物）。由于摄像机和项圈在时间上完全同步，我们可以逐步检查项圈数据和狩猎视频，包括地形，障碍物和与猎物的互动。我们将使用统计分析技术和计算机建模相结合的方法来研究限制和辅助性能，如抓地力，肌肉力量要求，转弯开始和尾巴运动。解释猎豹的速度和敏捷性的关键可能在于它的肌肉。因此，我们将研究猎豹肌肉纤维收缩的速度和强度（通过研究使用细活检针采集的微小样本），以了解其特性是否与其他猫科动物或其他精英表演动物（如人类、赛马或灰狗）的特性不同。该项目将是第一个记录野生猎豹每天24小时如此详细的数据的项目。除了使我们能够了解猎豹如何实现其速度和机动性外，这些数据还将使我们能够以前所未有的细节探索猎豹的行为，家庭范围的使用和领土大小，这对于制定猎豹长期生存的管理策略是必要的。肌肉研究可能为科学家提供新的信息，为人类和动物的肌肉问题开发新的治疗方法。我们的研究结果和数据收集技术将为科学家提供新的工具，不仅研究生物力学，行为和生态学，而且还为那些希望了解野生种群中疾病传播的科学家提供新的工具。我们希望我们的工作也能引起工程师的兴趣，因为了解猎豹的设计可能有助于设计重量更轻，腿更快的机器人和军事，因为技术和分析方法可以用于跟踪战场上的士兵。最后，我们希望我们的工作能够吸引公众，展示数学、工程学和生物学如何帮助我们揭开自然的秘密，并激励未来的科学家。

A cheetah can sprint at 65 mph, making it the fastest land animal by far - elite racing greyhounds and racehorses (and zoo cheetahs chasing a lure) only manage 40 mph. Cheetahs are also highly manoeuvrable, allowing them to catch even the most agile of prey. But what is it about the cheetah that enables it to do this? At the moment we simply don't know. The highly cited 'cheetah top speed' comes from just three measured runs by one individual cheetah in 1965. To find out, we need to measure the performance of cheetah during hunting in the wild - the only time that peak speed and manoeuvring are achieved. However, whilst cheetahs are believed to hunt almost daily, hunting is hard to observe directly.We plan to fit wild cheetah with collars equipped with unique technology that we have developed especially for this type of work. Each collar contains a special high accuracy GPS to pinpoint location and speed along with acceleration sensors, miniature gyroscopes, a compass and a tiny low power computer. The sensors can detect the cheetah's exact footfall pattern - how many strides and when each foot is on the ground. The collars monitor where the cheetah is and what it is doing - resting, walking, and most importantly, hunting and only collects detailed information when the cheetah is moving quickly (logging data up to 300 times per second). From the data, we can reconstruct the exact movement of the cheetah during a hunt. At other times, regular position updates and behaviour are recorded and the integrated solar panels recharge the batteries. The collar data is stored for later download via an integral radio-link.We aim to film cheetah hunts from the ground and air using a high resolution high speed video camera on a mount that automatically points at a GPS derived location. The collars tell the mount where to point the camera via a radio link and the camera tracks the cheetah's movement (we actually aim the camera just ahead of the cheetah to see the prey as well). Because the cameras and collars are exactly synchronised in time, we can examine the collar data and video footage of the hunt step by step, including the terrain, obstacles and interaction with the prey. We will use a combination of statistical analysis techniques and computer modelling to examine limits and aids to performance like grip, muscle power requirements, turn initiation and tail movement.The key to explaining the cheetah's speed and agility may lie in its muscles. Therefore we will study how quickly and powerfully cheetah muscle fibres can contract (by studying miniscule samples taken using a fine biopsy needle) to find out whether its properties differ from those of other cats or other elite performance animals such as humans, racehorses or greyhounds.This project will be the first to record such detailed data on wild cheetahs 24 hours a day. As well as enabling us to find out how cheetahs achieve their speed and manoeuvrability, these data will also enable us to explore - in unprecedented detail - cheetah behaviour, home range use and territory size, which is necessary to develop management strategies for the cheetah's long-term survival. The muscle studies may contribute new information for scientists working to develop new treatments for muscle problems in humans and animals. Our results and data collection techniques will provide new tools for scientists working not only on biomechanics, behaviour and ecology, but also those wanting to understand the spread of disease in wild populations. We expect our work also to be of interest to engineers, as understanding the cheetah's design may contribute to the design of lighter weight, faster legged robots and the military too, as the technology and analytical methods could be used for tracking soldiers on the battlefield. Finally, we hope our work will engage the public, showcasing how maths, engineering, and biology can help us unravel nature's secrets and inspire scientists of the future.