Abstract:
Predation threat is a major driver of behavior in many prey species. Animals can recognize their relative risk of predation based on cues in the environment, including visual and/or chemical cues released by a predator or from its prey. When threat of predation is high, prey often respond by altering their behavior to reduce their probability of detection and/or capture. Here, we test how a clonal fish, the Amazon molly (Poecilia formosa), behaviorally responds to predation cues. We measured aggressive and social behaviors both under \'risk\', where chemical cues from predatory fish and injured conspecifics were present, and control contexts (no risk cues present). We predicted that mollies would exhibit reduced aggression towards a simulated intruder and increased sociability under risk contexts as aggression might increase their visibility to a predator and shoaling should decrease their chance of capture through the dilution effect. As predicted, we found that Amazon mollies spent more time with a conspecific when risk cues were present, however they did not reduce their aggression. This highlights the general result of the \'safety in numbers\' behavioral response that many small shoaling species exhibit, including these clonal fish, which suggests that mollies may view this response as a more effective anti-predator response compared to limiting their detectability by reducing aggressive conspecific interactions.
摘要:
捕食威胁是许多猎物行为的主要驱动因素。动物可以根据环境中的线索识别它们的相对捕食风险,包括捕食者或猎物释放的视觉和/或化学线索。当捕食威胁很高时,猎物通常通过改变其行为来降低其检测和/或捕获的概率。这里,我们测试克隆鱼,亚马逊莫利(Poeciliaformosa),对捕食线索的行为反应。我们在“风险”下测量了攻击性和社交行为,存在来自掠食性鱼类和受伤物种的化学线索,和控制上下文(不存在风险线索)。我们预测,由于侵略可能会增加它们对捕食者的可见度,而浅滩则会通过稀释效应减少捕获它们的机会,因此在风险环境下,对模拟入侵者的侵略将减少其社交能力。正如预测的那样,我们发现,当存在风险线索时,亚马逊莫利斯花了更多的时间与特定对象在一起,然而,他们并没有减少他们的侵略。这突出了许多小型浅滩物种表现出的“数量安全”行为反应的一般结果,包括这些克隆鱼,这表明,与通过减少积极的特异性相互作用来限制其可检测性相比,莫利斯可能将这种反应视为更有效的抗捕食者反应。