Wildlife passages are currently built at roads and railway lines to re-establish connectivity. However, little is known about whether predator-prey interactions may reduce the effectiveness of the crossing structures. We evaluated the co-occurrence patterns of predator-prey species-pairs at 113 crossing structures, noting their coincidence at the same structure and/or on the same day. We built occupancy models using presence-absence matrices for three prey and five predator types obtained during 2076 passage-days of monitoring. The results indicate that predators and prey do not use passages independently. Attraction or segregation effects occurred in 20% of predator-prey species-pairs and were detected in 67% of cases with respect to same-day use. Our results show that both predator and prey species used the same structures to cross fenced roads. However, the spatial and daily patterns of crossing suggest that there were predators that attended crossings to search for prey and that prey species avoided using crossings in the presence of predators. Our results support two recommendations to avoid crossing structures losing effectiveness or becoming prey traps: (i) increase the number of wider structures to reduce the risks of predator-prey encounters and (ii) include inside them structural heterogeneity and refuges, to reduce the likelihood for predator-prey interactions.

中文翻译：

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道路野生动物过境点上的食肉动物与猎物之间的吸引力和回避

目前在公路和铁路线上修建了野生动物通道，以重新建立连接。但是，鲜有关于捕食者与猎物之间的相互作用是否会降低交叉结构有效性的鲜为人知。我们评估了113个交叉结构的捕食者与被捕食物种对的共现模式，并指出它们在同一结构和/或同一天的巧合。我们使用了在场状态不存在矩阵，针对在2076个监测日内获得的三种猎物和五种捕食者类型建立了占用模型。结果表明，捕食者和猎物没有独立使用通道。吸引或隔离效应发生在20％的捕食者-猎物对中，并且在当日使用率的67％的情况下被发现。我们的结果表明，捕食者和猎物物种都使用相同的结构穿越围栏道路。但是，越境的空间和日常模式表明，有掠食者参加过越境以寻找猎物，并且在有掠食者的情况下避免使用越境来捕食物种。我们的结果支持两个建议，以避免越过结构失去效力或成为捕食陷阱：（i）增加更广泛的结构的数量，以减少捕食者与猎物相遇的风险；（ii）在其中包括结构异质性和庇护所，以减少可能性用于捕食者与猎物的相互作用。