Format: ORAL

Jonathan G. Pattrick

University of Oxford

One way in which nectar sugar concentration can contribute to partitioning of pollinator floral preferences is through between-species differences in how viscosity influences rates of nectar transport. However, preferred nectar sugar concentrations may also vary between species depending on the strategy, or currency through which pollinators are optimising their foraging. Here I discuss our recent work in bumblebees investigating both of these factors. Firstly, we investigated how nectar viscosity influences multiple aspects of nectar transport. Secondly, to explore the energetics of foraging, we used a lab-based assay using a biomechanical foraging challenge to test if bumblebees can make a trade-off between nectar valence and the time/energy expended obtaining it. Bee foraging behaviour in this paradigm was in agreement with maximisation of the currency of net rate, but not in agreement with maximisation of the currency of energy efficiency. Given this currency differs from reported results in honeybees, we consider the implications for expected floral preferences between these two important generalist pollinators.