Floral humidity as a reliable sensory cue for profitability assessment by nectar-foraging hawkmoths.

ABSTRACT: Most research on plant-pollinator communication has focused on sensory and behavioral responses to relatively static cues. Floral rewards such as nectar, however, are dynamic, and foraging animals will increase their energetic profit if they can make use of floral cues that more accurately indicate nectar availability. Here we document such a cue--transient humidity gradients--using the night blooming flowers of Oenothera cespitosa (Onagraceae). The headspace of newly opened flowers reaches levels of about 4% above ambient relative humidity due to additive evapotranspirational water loss through petals and water-saturated air from the nectar tube. Floral humidity plumes differ from ambient levels only during the first 30 min after anthesis (before nectar is depleted in wild populations), w

SUBMITTER: von Arx M 

PROVIDER: S-EPMC3386090 | biostudies-literature | 2012 Jun

REPOSITORIES: biostudies-literature