Honeybees directly outcompete other flower visitors through interference competition on shared resource

Abstract Interspecific competition, whereby individuals of one species are in competition with individuals of another species, occurs naturally throughout invertebrate communities, and in pollinators, it manifests as exploitative or interference competition. Exploitative competition has been suggested as the primary mechanism of competition between managed bees and other pollinators; however, interference competition may also be a significant factor. Apis mellifera Linnaeus, 1758 (honeybee), primarily a managed bee species, where highly abundant, has a negative impact on native non‐ Apis pollinators. It is important to understand the nature of competition between wild and managed species to better conserve wild pollinators. The results presented here add new depth to existing literature about behavioural interactions among honeybees and non‐ Apis pollinators, evidencing interference competition and categorising the incidence of focal behaviours on highly utilised seasonal resources. We observed the behaviours of pollinators foraging on Rubus fruticosus Linnaeus, 1753 (bramble) and Hedera helix Linnaeus, 1753 (ivy), high‐value resources, which are a seasonally important food source for a wide range of pollinators in periods where naturally occurring flowers are scarce. Observations took place across 2 years at UK sites in close proximity to honeybee hives. We documented the outcome of 300 pairs of interactions, amounting to 93 h of observation time. The outcomes were recorded as ‘win’ where one individual gains access to the resource, resulting in a ‘loss’ of forage for the opposite interacting partner, or ‘share’ where two gain access to the resource in parallel with no interaction. Overall, honeybee abundance strongly negatively influenced the abundance of non‐ Apis pollinators. Competitive interactions were more frequent and led to greater than expected ‘wins’ for honeybees. Honeybees were avoided in 28.4% of interactions on bramble and 35.6% on ivy. The honeybee displaced or gave chase when interacting with another pollinator in at least 20% of winning outcomes on both plant species. We conclude that honeybees dominate shared resources by restricting the access of other pollinators to resources and that the importance of interference competition in pollinator communities is being underestimated.