Social prey species respond to predation risk by modifying habitat selection and grouping behaviour. These responses may depend on both actual predation risk (predator probability of occurrence) and/or on perceived predation risk associated with habitat structure. Other factors like food availability and co‐occurrence with other species may also affect habitat selection and group formation. We analyse habitat selection and grouping behaviour (group size and cohesion) of lesser rhea (Rhea pennata subsp. pennata), a ratite endemic of South America inhabiting steppe shrublands and grasslands, in relation to actual (puma probability of occurrence) and perceived (habitat structure: openness, visibility) predation risk, co‐occurrence with other herbivore species and forage availability in the Chilean Patagonia. We used data from 9 sampling seasons in 5 years. Results show that habitat selection, group size and cohesion in lesser rhea were mainly driven by variables associated with perceived predation risk and by co‐occurrence with other herbivores both during breeding and non–breeding season. As expected, lesser rhea preferred open habitats (vegas and grasslands) that allow a behaviour of ‘watch and run’ to avoid predation and formed larger groups in them. Moreover, lesser rhea positively selected year‐round habitats where livestock occur, forming large groups during non–breeding season there. Group size and co‐occurrence with other herbivores significantly decreased group cohesion, suggesting a reduction of perceived predation risk. Therefore, lesser rhea seems to take advantage of forming mixed interspecific groups to reduce predation risk. These results suggest that lesser rhea habitat selection and grouping behaviour are preferentially driven by factors related to perceived predation risk than by actual predator occurrence or food availability.

中文翻译：

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栖息地的结构和与有蹄类动物的联系驱动着栖息地的选择和小瑞亚的分组行为（Rhea pennata subsp。pennata）

社会猎物物种通过改变栖息地选择和分组行为来应对捕食风险。这些反应可能既取决于实际的捕食风险（发生捕食者的可能性），又取决于依赖于栖息地结构的捕食风险。其他因素，例如食物供应和与其他物种的共存，也可能影响栖息地的选择和群体形成。我们分析栖息地的选择和分组行为较少瑞亚（（集团规模和凝聚力）雷亚禾亚种禾），南美草原特有种，栖息于草原灌木丛和草原，与实际（美洲豹发生概率）和感知（栖息地结构：开放性，可见性）的捕食风险，与其他草食动物物种的共现以及智利牧草的可利用性有关巴塔哥尼亚。我们使用了5年中9个采样季节的数据。结果表明，在较小的Rhea中，栖息地的选择，种群规模和内聚力主要是由与捕食风险相关的变量以及在繁殖和非繁殖季节与其他草食动物的共生所驱动的。不出所料，较少的美洲红树喜欢开放的生境（维加斯和草原），这些生境允许人们“观察并逃跑”以避免掠食，并在其中形成较大的群体。此外，较少的美洲红树为人们全年选择的牲畜栖息地，在非繁殖季节形成大群。小组规模和与其他草食动物的共生显着降低了小组的凝聚力，表明减少了被捕食的风险。因此，较小的土卫八似乎利用形成混合的种间基团来降低捕食风险。这些结果表明，与实际捕食者的发生或食物供应量相比，较少的土生动物栖息地选择和分组行为是由与感知到的捕食风险相关的因素驱动的。