Does intraspecific behavioural variation of pollinator species influence pollination? A quantitative study with hummingbirds and a Neotropical shrub

• Floral visitors differ in their efficacy as pollinators and the impact of different pollinator species on the pollen flow and plant reproduction has been frequently evaluated. In contrast, the impact of within-species foraging changes on their efficacy as pollinators has been seldom quantified. • We studied a self-incompatible shrub Palicourea rigida (Rubiaceae) and its hummingbird pollinators which adjust their behaviour according to floral resources availability. Fluorescence microscopy was used to access pollen tube growth and incompatibility reaction in pistils after a single visit of territorial or intruder hummingbirds in two populations. To characterize the plant populations and possible differences on resource availability between areas we used a three-term quadrat variance method to detect clusters of floral resources. • Within species variation in foraging behaviour, but not the species identity affected pollinator efficacy. Effectively, hummingbirds intruding territories deposited more compatible pollen grains on P. rigida stigmas than territory holders in both study areas. Additionally, territory holders deposited more incompatible than compatible pollen grains. • Our results imply that intraspecific foraging behaviour variation has consequences for pollination success. Quantifying such variation and addressing the implications of intraspecific variability contribute to a better understanding of the dynamics and consequences of plant-pollinators interactions. This article is protected by copyright. All rights reserved.