Pollinators can be a limited resource and natural selection should favour differences in phenotypic characteristics to reduce competition among plants. Bats are important pollinators of many Neotropical plants, including the Bromeliaceae; however, the pre-pollination mechanisms for isolation among sympatric bat-pollinated bromeliads are unknown. Here, we studied the mechanisms for reproductive segregation between Pitcairnia recurvata, Pseudalcantarea viridiflora, Werauhia noctiflorens and W. nutans. The study was conducted at Los Tuxtlas Biosphere Reserve, in Veracruz, Mexico We carried out ex situ and in situ manual pollination treatments to determine the breeding system by assessing fruiting and seedling success and sampled bat visitors using mist-nets and infrared cameras. We determined the nocturnal nectar production pattern, estimating the energetic content of this reward. All four bromeliads are self-compatible, but only P. recurvata appears to require pollinators, because the physical separation between anthers and stigma prevents self-pollination, it is xenogamous and presents a strictly nocturnal anthesis. The bats Anoura geoffroyi, Glossophaga soricina and Hylonycteris underwoodi are probable pollinators of three of the studied bromeliads. We did not record any animal visiting the fourth species. The flowering season of each species is staggered throughout the year, with minimal overlap, and the floral morphology segregates the locations on the body of the bat where the pollen is deposited. The most abundant nectar per flower is provided by P. viridiflora, but P. recurvata offers the best reward per hectare, considering the density of flowering plants. Staggered flowering, different pollen deposition sites on the body of the pollinator and differences in the reward offered may have evolved to reduce the competitive costs of sharing pollinators while providing a constant supply of food to maintain a stable nectarivorous bat community.

中文翻译：

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凤梨科动物变得活跃：传粉者在同伴性手翅类凤梨科中分配。

授粉媒介可能是有限的资源，自然选择应有利于表型特征的差异，以减少植物之间的竞争。蝙蝠是许多新热带植物（包括凤梨科）的重要传粉媒介。但是，尚不清楚蝙蝠传粉同胞异粉虱之间的分离前传粉机制。在这里，我们研究了Pitcairnia recurvata，Pseudalcantarea viridiflora，Werauhia noctiflorens和W. nutans之间生殖隔离的机制。该研究在墨西哥韦拉克鲁斯州的Los Tuxtlas生物圈保护区进行。我们进行了异地和原地人工授粉处理，通过评估结果和幼苗成功来确定繁殖系统，并使用薄雾网和红外摄像头对蝙蝠访客进行了采样。我们确定了夜间花蜜的生产方式，估算此奖励的能量含量。所有四个凤梨科植物都是自交的，但是似乎只有花粉线虫需要传粉者，因为花药和柱头之间的物理隔离阻止了自花授粉，它是异种的，并且表现出严格的夜间花粉。蝙蝠Anoura geoffroyi，Glossophaga soricina和Hylonycteris underwoodi可能是三个研究凤梨科的传粉者。我们没有记录有任何动物造访第四种。每个物种的开花季节全年交错，重叠最小，花的形态将蝙蝠体上花粉沉积的位置隔离开。每朵花中最丰富的花蜜是由绿色假单胞菌提供的，但考虑到开花植物的密度，P。recurvata可以提供每公顷最佳的花蜜。