Estación Experimental de Zonas Áridas, EEZA-CSIC, Ctra. de Sacramento S/N, La Cañada de San Urbano, 04120 Almeria, Spain.
Proc Biol Sci. 2013 May 22;280(1763):20130886. doi: 10.1098/rspb.2013.0886. Print 2013 Jul 22.
Predator avoidance and foraging often pose conflicting demands. Animals can decrease mortality risk searching for predators, but searching decreases foraging time and hence intake. We used this principle to investigate how prey should use information to detect, assess and respond to predation risk from an optimal foraging perspective. A mathematical model showed that solitary bees should increase flower examination time in response to predator cues and that the rate of false alarms should be negatively correlated with the relative value of the flower explored. The predatory ant, Oecophylla smaragdina, and the harmless ant, Polyrhachis dives, differ in the profile of volatiles they emit and in their visual appearance. As predicted, the solitary bee Nomia strigata spent more time examining virgin flowers in presence of predator cues than in their absence. Furthermore, the proportion of flowers rejected decreased from morning to noon, as the relative value of virgin flowers increased. In addition, bees responded differently to visual and chemical cues. While chemical cues induced bees to search around flowers, bees detecting visual cues hovered in front of them. These strategies may allow prey to identify the nature of visual cues and to locate the source of chemical cues.
捕食者回避和觅食常常存在冲突的需求。动物可以通过寻找捕食者来降低死亡率，但寻找会减少觅食时间，从而减少摄入量。我们利用这一原理，从最优觅食的角度研究了猎物应该如何利用信息来检测、评估和应对捕食风险。一个数学模型表明，独居蜜蜂应该根据捕食者线索增加对花朵的检查时间，而错误警报的频率应该与所探索花朵的相对价值呈负相关。捕食性蚂蚁 Oecophylla smaragdina 和无害蚂蚁 Polyrhachis dives 在释放的挥发性物质的特征和视觉外观上有所不同。正如预测的那样，独居蜜蜂 Nomia strigata 在有捕食者线索的情况下比在没有线索的情况下花更多的时间检查处女花。此外，随着处女花相对价值的增加，从早上到中午，被拒绝的花朵比例下降。此外，蜜蜂对视觉和化学线索的反应不同。虽然化学线索诱导蜜蜂在花朵周围搜索，但蜜蜂检测到视觉线索时会在它们前面盘旋。这些策略可能使猎物能够识别视觉线索的性质，并找到化学线索的来源。
