Flower movement balances pollinator needs and pollen protection

Flower signaling and orientation are key characteristics, which determine a flower’s pollinator guild. However, many flowers actively move during their daily cycle, changing both their detectability and accessibility to pollinators. The flowers of the wild tobacco Nicotiana attenuata orientate their corolla upwards at sunset and downwards after sunrise. Here, we investigated the effect of different flower orientations on a major pollinator of N. attenuata, the hawkmoth Manduca sexta. We found that although flower orientation influenced the flight altitude of the moth in respect to the flower, it did not alter its overall attractiveness. These behavioral observations were consistent with the finding that orientation did not systematically change the spatial distribution of floral volatiles, which are major attractants for moths. Moreover, moths invested the same amount of time into probing flowers at different orientations, even though they were only able to feed and take up pollen from ...