Nectar Robbers, Pollinators, and Plants: The Importance of Direct and Indirect Effects on Individuals and Communities

[806501]艾莉森·布罗迪进化生态学家的一个基本目标是了解物种之间的相互作用如何决定它们的数量和设计。多年来，植物与传粉者之间的相互作用受到了广泛的关注，这些研究对物种相互作用的生态学和进化产生了许多见解。然而，一些访花者不给寄主植物授粉，事实上，这可能会造成严重的危害。其中一群动物是花蜜劫匪——在不影响授粉的情况下掠夺花蜜的动物。本研究的重点是研究掠夺花蜜的大黄蜂（Bombus occidentalis）如何影响其亚高山寄主植物红gilia （Ipomopsis aggregata）的成功，并间接影响开花植物群落的其他成员。该研究将操纵性实验与观察相结合，以检验三个主要假设：(1)抢蜜者影响了被蜂鸟传粉的植物红百合实现的雄性和雌性适合度；(2)在吸引传粉者中已知的重要花性状也吸引了抢蜜者，从而可能介导花的进化；(3)抢蜜者通过改变蜂鸟传粉者对被抢和未被抢植物的行为，间接影响了共生植物物种的成功。这项工作是及时的，因为它解决了生态学家和进化生物学家长期感兴趣的问题，即多物种相互作用的重要性及其相互之间的直接和间接影响。该研究在了解多物种相互作用如何影响动物传粉植物的种子生产、花的进化和群落水平动态方面也具有应用意义。

9806501 Alison Brody A fundamental goal of evolutionary ecologists is to understand how interactions among species govern their abundance and design. The interactions among plants and their pollinators have received considerable attention over the years and these studies have yielded much insight into the ecology and evolution of species interactions. However, some floral visitors do not pollinate their host plants and, in fact, can do significant harm. One such group of animals is nectar robbers -- animals that rob flowers of nectar without effecting pollination. The focus of this study is to examine how a nectar robbing bumblebee, Bombus occidentalis, affects the success of its sub-alpine host plant, scarlet gilia (Ipomopsis aggregata), and indirectly affects other members of the flowering plant community. The research combines manipulative experiments with observations to test three overarching hypotheses: (1) nectar robbers affect realized male and female fitness of the hummingbird-pollinated plant, scarlet gilia, (2) floral traits known to be important in attracting pollinators also attract nectar robbers which may thus mediate floral evolution, and (3) nectar robbing indirectly affects the success of co-occurring plant species by changing the behavior of hummingbird pollinators toward robbed and unrobbed plants. The work is timely in that it addresses a question of long-standing interest to ecologists and evolutionary biologists, i.e., the importance of multiple species interactions and their direct and indirect effects on each other. The work also has applied significance in understanding how multiple species interactions combine to affect the seed production of animal pollinated plants, their floral evolution, and community-level dynamics.