Echolocating bats use a nearly time-optimal strategy to intercept prey.
Echolocating bats use a nearly time-optimal strategy to intercept prey.
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DOI：
10.1371/journal.pbio.0040108
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发表时间：
2006-05
期刊：
影响因子：
9.8
通讯作者：
Moss, Cynthia F
中科院分区：
文献类型：
--
作者：
Ghose, Kaushik;Horiuchi, Timothy K;Krishnaprasad, P S;Moss, Cynthia F
许多动物物种的食物获取取决于对移动猎物的追捕和捕获。在现代人类中，追逐和拦截移动目标在网球、足球、飞盘和棒球等各种运动中起着核心作用。对从蜻蜓、鱼、狗到人类等动物的目标追踪研究表明，它们都使用恒定方位（CB）策略来追踪猎物或其他移动目标。 CB 最著名的是棒球外野手用来接住弹道飞球的拦截策略。 CB 是一种时间最优的解决方案，可以捕捉沿直线或以可预测的方式移动的目标，例如弹道棒球或沉入水中的食物。然而，许多动物必须捕捉可能做出躲避和不可预测的动作的猎物。 CB 是追踪不规则移动目标的最佳解决方案吗？面对如此不稳定的猎物，动物也会使用CB吗？在本文中，我们通过研究食虫回声定位蝙蝠的猎物捕捉来解决这些问题。回声定位蝙蝠依靠声纳来追踪和捕捉飞行的昆虫。蝙蝠的猎物可能会从树叶中出现一小段时间，在返回掩体之前沿着不稳定的三维路径飞行。蝙蝠通常需要不到一秒钟的时间来检测、定位和捕获此类昆虫。我们使用高速立体红外摄像来研究大棕蝠（Eptesicus fuscus）在黑暗的实验室飞行室中追逐不规则移动的昆虫时的三维飞行路径。我们使用简单的延迟微分方程量化了蝙蝠复杂的追踪轨迹。我们对追踪轨迹的分析表明，蝙蝠在追踪过程中使用恒定的绝对目标方向策略。我们从数学上证明，与CB不同，这种方法最大限度地减少了追踪者拦截不可预测的移动目标所需的时间。有趣的是，蝙蝠的行为与某些导弹实施的拦截策略类似。我们认为，蝙蝠采用的时间最优策略是为了应对必须捕获不稳定且快速移动的昆虫的进化压力。 对大棕蝠三维飞行路径的分析揭示了与某些导弹所使用的拦截目标类似的策略。
Acquisition of food in many animal species depends on the pursuit and capture of moving prey. Among modern humans, the pursuit and interception of moving targets plays a central role in a variety of sports, such as tennis, football, Frisbee, and baseball. Studies of target pursuit in animals, ranging from dragonflies to fish and dogs to humans, have suggested that they all use a constant bearing (CB) strategy to pursue prey or other moving targets. CB is best known as the interception strategy employed by baseball outfielders to catch ballistic fly balls. CB is a time-optimal solution to catch targets moving along a straight line, or in a predictable fashion—such as a ballistic baseball, or a piece of food sinking in water. Many animals, however, have to capture prey that may make evasive and unpredictable maneuvers. Is CB an optimum solution to pursuing erratically moving targets? Do animals faced with such erratic prey also use CB? In this paper, we address these questions by studying prey capture in an insectivorous echolocating bat. Echolocating bats rely on sonar to pursue and capture flying insects. The bat's prey may emerge from foliage for a brief time, fly in erratic three-dimensional paths before returning to cover. Bats typically take less than one second to detect, localize and capture such insects. We used high speed stereo infra-red videography to study the three dimensional flight paths of the big brown bat, Eptesicus fuscus, as it chased erratically moving insects in a dark laboratory flight room. We quantified the bat's complex pursuit trajectories using a simple delay differential equation. Our analysis of the pursuit trajectories suggests that bats use a constant absolute target direction strategy during pursuit. We show mathematically that, unlike CB, this approach minimizes the time it takes for a pursuer to intercept an unpredictably moving target. Interestingly, the bat's behavior is similar to the interception strategy implemented in some guided missiles. We suggest that the time-optimal strategy adopted by the bat is in response to the evolutionary pressures of having to capture erratic and fast moving insects. Analysis of the three dimensional flight paths of the big brown bat reveals a similar strategy to intercept targets as used by some guided missiles.