Grason Emily W
Am Nat. 2017 Mar;189(3):213-226. doi: 10.1086/690217. Epub 2017 Jan 12.
Though prey use a variety of information sources to assess predation risk, evolutionary cohistory with a predator could constrain information use, and nonnative prey might fail to recognize risk from a novel predator. Nonnative prey might instead use generalized risk assessment, relying on general alarm signals from injured conspecifics rather than cues from predators. I tested the influence of shared predator-prey history on information use, comparing responses among three native and four nonnative prey species to chemical cues from a native predator and cues from injured conspecific prey. Nonnative prey demonstrated information generalism: (1) responding stronger to alarm cues released by injured conspecific prey than to cues from predators and (2) responding similarly to alarm cues as to cues from predators consuming injured conspecific prey. By contrast, for native prey, multiple information sources were required to elicit the greatest defense. The influence of other sources of chemical information was not predicted by cohistory with the predator: only one nonnative snail responded to the predator; digestion was important for only two native species; the identity of injured prey was important for all prey; and predator and prey cues contributed additively to prey response. Information generalism, hypothesized to be costly in coevolved interactions, could facilitate invasions as a driver of or response to introduction to novel habitats.
尽管猎物会利用多种信息来源来评估捕食风险，但与捕食者的进化共同历史可能会限制信息的使用，而且外来猎物可能无法识别来自新捕食者的风险。相反，外来猎物可能会采用通用的风险评估方式，依赖于受伤同种个体发出的一般警报信号，而非来自捕食者的线索。我测试了捕食者与猎物的共同历史对信息使用的影响，比较了三种本地猎物物种和四种外来猎物物种对来自本地捕食者的化学线索以及来自受伤同种猎物的线索的反应。外来猎物表现出信息通用性：（1）对受伤同种猎物释放的警报线索的反应比对捕食者线索的反应更强；（2）对警报线索的反应与对正在捕食受伤同种猎物的捕食者线索的反应相似。相比之下，对于本地猎物，需要多种信息来源才能引发最强的防御反应。与捕食者的共同历史并不能预测其他化学信息来源的影响：只有一种外来蜗牛对捕食者有反应；消化作用仅对两种本地物种很重要；受伤猎物的身份对所有猎物都很重要；捕食者和猎物的线索对猎物反应的影响是相加的。信息通用性在共同进化的相互作用中被认为是有代价的，它可能作为入侵新栖息地的驱动因素或对引入新栖息地的反应，从而促进入侵。
