A comparative analysis of foraging route development by bumblebees and honey bees.

Many pollinators, such as bees, hummingbirds and bats, use multi-destination routes (traplines) to exploit familiar plant resources. However, it is not clear to what extent the mechanisms underpinning trapline development and optimisation are comparable across species. Here we compared route formation, repeatability and efficiency by foragers of two social bee species, the solo foraging bumblebee Bombus terrestris and the mass foraging honey bee Apis mellifera, in the same laboratory conditions. In a simple routing task (with four artificial flowers), all bumblebees and honey bees developed a route, although honey bees were slower to do so. In a more complex routing task (with six flowers), however, only bumblebees developed a route between the 6 flowers. Honey bees took a longer time to discover all flowers and developed routes between fewer flowers. Comparing bumblebees and honey bees using the same experimental paradigm thus revealed key behavioural differences likely resulting from their contrasting collective foraging strategies. Significance statement: Pollinators face some of the most complex foraging challenge among animals: collecting small amounts of nectar from large numbers of flowers in a minimum of time. Previous studies report bees, birds and bats rely on spatial memory to develop routes optimising foraging efficiency. Here we compared this routing behaviour in two major pollinators, the buff-tailed bumblebee and the Western honey bee, in the same experimental conditions. We found that bumblebees were much faster and more efficient at visiting flowers following repeatable sequences than honey bees. This behavioural difference suggests bee cognition is shaped by their social ecology and illuminates about the known complementarity of different bee species for pollination. [ABSTRACT FROM AUTHOR]