Penning David A, Sawvel Baxter, Moon Brad R
Department of Biology, University of Louisiana at Lafayette, Lafayette, LA 70504, USA
Department of Biology, University of Louisiana at Lafayette, Lafayette, LA 70504, USA.
Biol Lett. 2016 Mar;12(3):20160011. doi: 10.1098/rsbl.2016.0011.
To survive, organisms must avoid predation and acquire nutrients and energy. Sensory systems must correctly differentiate between potential predators and prey, and elicit behaviours that adjust distances accordingly. For snakes, strikes can serve both purposes. Vipers are thought to have the fastest strikes among snakes. However, strike performance has been measured in very few species, especially non-vipers. We measured defensive strike performance in harmless Texas ratsnakes and two species of vipers, western cottonmouths and western diamond-backed rattlesnakes, using high-speed video recordings. We show that ratsnake strike performance matches or exceeds that of vipers. In contrast with the literature over the past century, vipers do not represent the pinnacle of strike performance in snakes. Both harmless and venomous snakes can strike with very high accelerations that have two key consequences: the accelerations exceed values that can cause loss of consciousness in other animals, such as the accelerations experienced by jet pilots during extreme manoeuvres, and they make the strikes faster than the sensory and motor responses of mammalian prey and predators. Both harmless and venomous snakes can strike faster than the blink of an eye and often reach a target before it can move.
为了生存，生物体必须避免被捕食，并获取营养和能量。感觉系统必须正确区分潜在的捕食者和猎物，并引发相应调整距离的行为。对于蛇来说，攻击可以达到这两个目的。蝰蛇被认为是蛇类中攻击速度最快的。然而，只有极少数物种的攻击性能得到过测量，尤其是非蝰蛇。我们使用高速视频记录，测量了无害的德州鼠蛇以及两种蝰蛇——西部水腹蛇和西部菱斑响尾蛇的防御性攻击性能。我们发现鼠蛇的攻击性能与蝰蛇相当或更胜一筹。与过去一个世纪的文献记载相反，蝰蛇并非蛇类攻击性能的巅峰。无害蛇和毒蛇都能以极高的加速度发动攻击，这会产生两个关键后果：加速度超过了能使其他动物失去意识的值，比如喷气式飞机飞行员在极端机动时所经历的加速度；而且它们的攻击速度比哺乳动物猎物和捕食者的感觉和运动反应还要快。无害蛇和毒蛇的攻击速度都比眨眼还快，而且常常在目标能够移动之前就击中目标。
