The fear of unseen predators: ground squirrel tail flagging in the absence of snakes signals vigilance
The fear of unseen predators: ground squirrel tail flagging in the absence of snakes signals vigilance
复制标题
对看不见的掠食者的恐惧：地松鼠在没有蛇的情况下尾巴下垂表示警惕
DOI：
--
复制
发表时间：
2015
期刊：
影响因子：
--
通讯作者：
R. Clark
中科院分区：
文献类型：
--
作者：
Breanna J. Putman;R. Clark
许多动物并没有逃避捕食者，而是表现出引人注目的表现，人们认为这些表现是通过广告质量（身体能力）或对捕食者的认识来阻止攻击。然而，当捕食者不在时，猎物通常会表现出相同的反捕食者表现。在这种情况下发出的信号要么不诚实地表明捕食者的检测，要么诚实地表明警惕，但没有研究通过实验检验这些假设。我们通过模拟蛇的攻击并量化信号松鼠和非信号松鼠的攻击避免行为，测试了尾巴标记的警戒广告功能，这是加州地松鼠（Otospermophilus beecheyi）向响尾蛇（Crotalus oreganus）发出的信号。我们通过模拟攻击消除了蛇的存在对信号的影响：1）有响尾蛇存在，2）没有蛇存在，或3）在松鼠最近遇到不再存在的蛇的区域。当松鼠与蛇互动时，尾巴最容易下垂。松鼠也会在最近遇到蛇的区域发出信号，在这种情况下，它们对模拟攻击的反应更快，并且更有可能垂直或水平跳跃远离攻击。尾巴下垂率还与松鼠的身体位移时间和逃跑方式有关。在没有蛇在场的情况下，松鼠很少发出信号或表现出躲避跳跃。这些结果表明，即使捕食者未被发现，在没有捕食者的情况下的展示也可以诚实地表示警惕或准备避免攻击。这种反捕食者的展示可能很普遍，因为当不确定捕食者的位置时，许多物种可以从广告警觉中受益。
Rather than fleeing from predators, many animals exhibit conspicuous displays that are thought to deter attacks by advertising quality (physical capabilities), or awareness of the predator. However, prey commonly exhibit the same antipredator display when predators are absent. Signaling in this context could either dishonestly indicate predator detection, or honestly indicate vigilance, but no study has tested these hypotheses experimentally. We tested the vigilance advertisement function of tail flagging, a signal given by California ground squirrels (Otospermophilus beecheyi) to rattlesnakes (Crotalus oreganus), by simulating snake strikes and quantifying strike avoidance behaviors in signaling and non-signaling squirrels. We removed the effect of snake presence on signaling by simulating strikes 1) in the presence of a rattlesnake, 2) with no snake present, or 3) in an area where squirrels had recently encountered a snake that was no longer present. Squirrels tail flagged most when interacting with a snake. Squirrels also signaled in areas of recent snake encounters, and in this context, they responded faster to simulated strikes and were more likely to leap vertically or horizontally away from the attack. Tail flagging rate was also related to squirrels’ body displacement time and flee modality. Squirrels rarely signaled or exhibited evasive leaping with no snake present. These results indicate that displays in the absence of predators can honestly signal vigilance, or the readiness to avoid an attack, even if predators are undetected. Such antipredator displays may be widespread as many species could benefit from advertising alertness when uncertain of the location of predators.