Department of Zoology and Animal Cell Biology, Faculty of Science and Technology, University of the Basque Country UPV/EHU, Leioa, The Basque Country.
Behavioural Ecology and Conservation Group, Biodiversity Research Centre, Earth and Life Institute, UCLouvain, Louvain-La-Neuve, Belgium.
J Anim Ecol. 2019 Oct;88(10):1587-1600. doi: 10.1111/1365-2656.13055. Epub 2019 Jul 28.
The degree of trophic specialization determines the ability of predators to cope with changing foraging conditions, but in predators that prey on hundreds of species it is challenging to assess, especially when prey identity varies among predator individuals and across space and time. Here, we test the hypothesis that a bat species foraging on flying insects like moths will show ample flexibility in trophic niche, and this irrespective of phylogenetic relationships among moths, so as to cope with a high diversity of prey types that vary across seasons. We predict that individual bats will show functional dietary differences consistent with energetic requirements and hunting skills. We used DNA metabarcoding to determine the diet of 126 Mediterranean horseshoe bats (Rhinolophus euryale) from two different sites during three seasons. Simultaneously, we measured moth availability and characterized the traits of 290 moth taxa. Next, we explored the relationship between phylogeny and traits of all consumed and available moth taxa. Finally, we assessed the relationship between individual traits of bats and traits related to prey profitability, for which we used the RLQ and fourth-corner statistical techniques. Seasonality was the main factor explaining the functional dietary variation in adult bats, with moths consumed irrespective of their phylogenetic relationships. While adults consumed moths with a broad range in wing loading, body mass and echolocation detection ability, juveniles consumed slower, smaller and lighter moths, which suggests that young individuals may undergo some fitness gain and/or psychomotor learning process during which they would acquire more effective foraging skills. Our approach revealed a degree of functional flexibility in the trophic niche previously unknown for an insectivorous bat. Rhinolophus euryale consumed a wide variety of moth taxa differing in profitability throughout seasons and between ontogenetic stages. We showed the validity of trait-based approaches to gain new insights in the trophic specialization of predators consuming hundreds of species of prey.
营养特化程度决定了捕食者应对觅食条件变化的能力，但对于捕食者来说，捕食者捕食数百种物种，很难评估，尤其是当捕食者个体和跨越空间和时间的猎物身份不同时。在这里，我们检验了这样一个假设，即一种以飞蛾等飞行昆虫为食的蝙蝠物种在营养生态位上会表现出足够的灵活性，并且这种灵活性与飞蛾之间的系统发育关系无关，以便应对跨越季节的各种不同类型的猎物的高度多样性。我们预测，个体蝙蝠将表现出与能量需求和狩猎技能一致的功能饮食差异。我们使用 DNA 代谢组学来确定来自两个不同地点的 126 只地中海马蹄蝠（Rhinolophus euryale）在三个季节期间的饮食。同时，我们测量了飞蛾的可用性，并描述了 290 种飞蛾类群的特征。接下来，我们探索了所有消耗和可用飞蛾类群的系统发育与特征之间的关系。最后，我们评估了蝙蝠个体特征与与猎物盈利能力相关的特征之间的关系，为此我们使用 RLQ 和第四角统计技术。季节性是解释成年蝙蝠功能饮食变化的主要因素，消耗的飞蛾与其系统发育关系无关。虽然成年蝙蝠消耗了翅膀负荷、体重和回声定位检测能力范围广泛的飞蛾，但幼蝠则消耗速度较慢、体型较小和重量较轻的飞蛾，这表明年轻个体可能在一定程度上获得了适应性增益和/或心理运动学习过程，在此过程中，它们将获得更有效的觅食技能。我们的方法揭示了一种以前未知的食虫蝙蝠的营养生态位功能灵活性。欧亚马蹄蝠在整个季节和不同的个体发育阶段都消耗了各种盈利能力不同的飞蛾类群。我们展示了基于特征的方法在研究捕食者对数百种猎物的营养特化方面的有效性。
