Recent encounters with rattlesnakes enhance ground squirrel responsiveness to predator cues
Recent encounters with rattlesnakes enhance ground squirrel responsiveness to predator cues
复制标题
DOI：
10.1007/s00265-017-2378-1
复制
发表时间：
2017-10-01
影响因子：
2.3
通讯作者：
Clark, Rulon W.
中科院分区：
文献类型：
--
作者：
Ayon, Rey E.;Putman, Breanna J.;Clark, Rulon W.
当面对活的捕食者时，不同的猎物分类群表现出刻板的反捕食者行为。捕食者线索也会引发反捕食者反应，先前的研究表明，猎物具有区分特定捕食者线索所构成的相对风险的机制，这中介了它们对反捕食者行为(即B威胁敏感行为)的投资。然而，这种捕食者线索的显著程度可能会随着感知的捕食风险而变化，这可能会在时间或空间上发生变化。我们假设，根据猎物最近与捕食者的经验，猎物会改变对捕食线索的反应，这将使猎物关注与捕食者相关的线索。在目前的研究中，我们发现最近与活体系留响尾蛇的接触增加了自由放养的加州地松鼠(Otospermophilus Beecheyi)的感知捕食风险，导致了对捕食者模型表现出的反捕食者行为强度的增加。与新物体相比，蛇遭遇后反捕食者行为的增加更倾向于捕食者模型，这表明松鼠对类似捕食者的物体表现出威胁敏感的反应。然而，松鼠并没有谨慎地对待这两个物体中的任何一个，当没有遇到活蛇时，当他们看到模型或新物体时，它们的反捕食者行为也没有区别。这表明，捕食者遭遇后提高的警觉性调整了对捕食者暗示的反应。这种反捕食者行为的增加有助于快速发现附近的捕食者，但也可能对猎物产生间接影响。意义陈述对捕食者反应不足可能导致死亡，而过度反应可能会减少其他与健康相关的活动所花费的时间。猎物通过使用环境线索来改变反捕食者的反应来平衡这些成本。在环境中检测到活的捕食者可能表明被捕食的机会很高，这可能会增强猎物的反捕食者反应。我们发现，在遇到活生生的被拴住的响尾蛇捕食者后，地松鼠显著增强了对蛇模型和新对象的反捕食者行为。然而，与蛇相遇后的新物体相比，捕食者模型引发了更大的反捕食者行为，这表明松鼠在这种情况下已经准备好注意与捕食者相关的线索。当没有检测到蛇时，这两个物体都得到了类似的处理，而且不那么谨慎。因此，捕食者相互作用后的警觉中介了对后续捕食者线索的威胁敏感反应。
A diverse range of prey taxa exhibit stereotyped antipredator behaviors when confronting live predators. Predator cues also elicit antipredator responses, and previous research indicates that prey possess mechanisms to discriminate between the relative risk posed by particular predator cues, which mediates their investment in antipredator behaviors (i.e., Bthreatsensitive" behavior). However, the salience of such predator cues may change according to perceived predation risk, which can vary temporally or spatially. We hypothesized that prey modify responses to predatory cues according to their recent experience with predators, which would prime prey to attend to predator-related cues. In the present study, we found that recent encounters with live tethered rattlesnakes increased perceived predation risk in free-ranging California ground squirrels (Otospermophilus beecheyi), leading to concomitant increases in the intensity of antipredator behaviors displayed toward a predator model. The increase in antipredator behavior following snake encounters was higher toward the predator model than a novel object, suggesting that squirrels exhibit threat-sensitive responses toward objects resembling predators. However, squirrels did not treat either of these objects with caution, nor did they differ in antipredator behavior, when presented with the model or novel object when no live snake was encountered. This suggests that increased vigilance following predator encounters modulates responses to predator cues. Such increases in antipredator behavior could assist in detecting nearby predators quickly but could also have indirect effects on prey.Significance statementUnderresponding to predators could lead to death, while overresponding could reduce time spent on other fitnessrelated activities. Prey balance these costs by using environmental cues to modify antipredator responses. Detecting a live predator in the environment could indicate that the chance of predation is high, which may enhance preys' antipredator responses. We show that ground squirrels significantly enhance antipredator behaviors toward snake models and novel objects after encountering a live tethered rattlesnake predator. However, the predator model elicited greater antipredator behavior than the novel object following snake encounters, suggesting that squirrels are primed to attend to predator-related cues in this context. Both objects were treated similarly, and with less caution, when no snake was detected. Vigilance following predator interactions therefore mediates threatsensitive responses to subsequent predator cues.