Cavity Occupancy By Wild Honey Bees: Need For Evidence Of Ecological Impacts

The European honey bee (Apis mellifera) is managed worldwide for honey production and crop pollination, and is an invasive species in many countries. Wild colonies occupy natural and human-made cavities and are thought to impact other cavity-using species. We reviewed documented evidence of wild A mellifera nesting sites globally via a literature review (27 relevant studies) and citizen-science observations of wild honey bee colonies on iNaturalist (326 observations). Honey bee occupancy rates from published studies were typically low and occupation was often temporary. Citizen-science data showed that most colonies in cavities had small or narrow entrance holes. Current evidence of perceived competition with honey bees in cavities is largely anecdotal and little is known about the long-term impacts on survival and reproductive success of other cavity-occupying species. To guide conservation policy and practice, more empirical research is needed to understand the ecological outcomes of competitive interactions in nesting cavities.