Data from: Monitoring free-living honeybee colonies in Germany: Insights into habitat preferences, survival rates, and Citizen Science reliability

Our understanding of the western honeybee (Apis mellifera) predominantly
stems from studies conducted within beekeeping environments, leaving the
presence and characteristics of honeybees outside managed settings largely
unexplored. In this study, we examined the habitats, nesting sites, and
survival rates of free-living colonies through personal monitoring of nest
sites in Munich (N = 107) and the coordination of Citizen Science
monitoring across Germany (N = 423). Within seven years, we collected
2,555 observations on 530 colonies from 311 participants. Overall, we
found that 31 % of the occupied nest sites were in buildings and 63 % in
mature trees, with clear preferences for specific tree species. Nesting
preferences differed between urban, rural, and forested areas. On average,
only 12 % of the personal monitored colonies in Munich survived annually,
a figure that aligns well with other published studies but contrasts
sharply with the significantly higher survival rates reported by Citizen
Science (29 %). We found that Citizen Science yielded significantly fewer
updates per colony, underreported abandoned sites, and that 46 % of
overwintering reports overlapped with the swarming season and had to be
excluded. To gain reliable survival data in Citizen Science projects,
consistency and timing of reports need particular attention and regional
swarming should be monitored too. This study enhances our understanding of
the ecological dynamics, liminal state, and conservation needs of
free-living honeybee cohorts, addresses potential monitoring biases, and
suggests standardized data collection protocols for future monitoring
projects.