Honey bees adjust colour preferences in response to concurrent social information from conspecifics and heterospecifics

y Bees efficiently learn asocial and social cues to optimize foraging from fluctuating floral resources. However, it remains unclear how bees respond to divergent sources of social information, and whether such social cues might modify bees' natural preferences for nonsocial cues (e.g. flower colour), hence affecting foraging decisions. Here, we investigated honey bees', Apis mellifera, inspection and choices of unfamiliar flowers based on both natural colour preferences and simultaneous foraging information from conspecifics and heterospecifics. Individual honey bees' preferences for flowers were recorded when the reward levels of a learned flower type had declined and novel-coloured flowers were available where they would find either no social information or one conspecific and one heterospecific bumble bee, Bombus terrestris, each foraging from a different coloured flower (magenta or yellow). Honey bees showed a natural preference for magenta flowers. They modified their inspection of both types of flowers in response to conspecific and heterospecific social information. The presence of a conspecific demonstrator on the less-preferred yellow flower increased honey bees' inspection of yellow flowers and the likelihood of foraging on them, thus outweighing the original preference for magenta flowers. The presence of a heterospecific on a magenta flower increased honey bees' inspection of magenta flowers, but this effect was not observed when bumble bees fed on yellow flowers. Our results indicate that flower colour preferences of honey bees are rapidly adjusted in response to both conspecific and heterospecific presence, in different ways, with a preference for conspecific information possibly favouring the transmission of adaptive foraging information within species. (C) 2020 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.