Data from: Monitoring free-living honeybee colonies in Germany: Insights into habitat preferences, survival rates, and Citizen Science reliability
Data files
Apr 15, 2026 version files 172.40 KB
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README.md
12.12 KB
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rutschmann_remter_roth_dataset.xlsx
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Abstract
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.
https://doi.org/10.5061/dryad.fj6q57452
Description of the data and file structure
| Key for "nestsites" | |
|---|---|
| Data table provides information about the nestsites of free-living honeybee colonies in Germany. Each row contains data for a single cavity. | |
| column header | content |
| "id" | Unique identifier for each nest site |
| "height" | Height of the nest site in meters. |
| "direction" | Orientation or direction of the nest site entrance (e.g., north, south-west). |
| "type" | Type of cavity where the colony is located, such as tree cavity, rock crevice, house wall, chimney, or open-hanging comb. |
| "tree_species" | Tree species hosting the cavity, if the nest site is located in a tree (e.g., Oak, Maple, Lime). |
| "circumference" | Trunk circumference of the tree cavity in meters, measured at breast height. |
| "number_of_reports" | Total number of reports for this nest site over the study period. |
| "user_id" | Unique identifier for the user or observer who reported the nest site. |
| "discovered_by_us" | Indicates whether the nest site was discovered by the authors ('1') or by citizen scientists ('0'). |
| "monitor_by_us" | Indicates whether the nest site was monitored by the authors ('1') or not ('0'). |
| "land_cover_class" | Specific land cover class (e.g., broad-leaved forest, coniferous forest, urban fabric) for the nest site location, based on the CORINE Land Cover classification. |
| "broad_category" | Generalized land cover category (e.g., Urban, Deciduous forest, Coniferous forest) derived from the land cover class. |
| "coniferous_perc_in_2k" | Percentage of coniferous forest cover within a 2-kilometer buffer around the nest site. |
| "cropland_perc_in_2k" | Percentage of cropland within a 2-kilometer buffer around the nest site. |
| "deciduous_perc_in_2k" | Percentage of deciduous forest cover within a 2-kilometer buffer around the nest site. |
| "grassland_perc_in_2k" | Percentage of grassland within a 2-kilometer buffer around the nest site. |
| "settlement_perc_in_2k" | Percentage of settlement or urban areas within a 2-kilometer buffer around the nest site. |
| "water_perc_in_2k" | Percentage of water bodies (e.g., lakes, rivers) within a 2-kilometer buffer around the nest site. |
| "open_perc_in_2k" | Percentage of open land (e.g., bare soil or sparsely vegetated areas) within a 2-kilometer buffer around the nest site. |
| Key for "reports" | |
| Data table provides monitoring reports at the different nestsites at different times. Each row is a single report. | |
| column header | content |
| "id" | Unique identifier for each nest site. |
| "number_of_reports" | Total number of reports for this nest site over the study period. |
| "date" | Date of the observation. |
| "flight_activity" | Observed flight activity of the colony at the entrance of the nest site during the observation. |
| Key for "survival table" | |
| Data table provides life-histories and survival rates of free-living honeybee colonies in Germany. Each row contains data for a single cavity. | |
| column header | content |
| "id" | Unique identifier of the cavity. |
| "W14" till "W23" | Information on the overwintering status of a colony in the nestsite is provided in the columns 'W14' through 'W23.' For each year represented by these columns, the following numeric codes indicate the fate of the colony: '0' = colony did not survive the winter; '1' = colony successfully survived the winter; '2' = colony died in the fall (thus considered lost over the winter); '3' = colony died between winter and spring (thus considered lost over the winter). |
| "destroyed" | This column indicates whether a nest site was destroyed. A value of '1' means the nest site was destroyed. |
| "killed" | This column indicates whether a colony was killed. A value of '1' means the colony was killed. |
| "S09" till "S23" | These columns provide seasonal status information for each nest site over multiple years. 'S' stands for summer, 'H' for fall (Herbst), and 'F' for spring (Fruehling). In these columns, 'A' means the nest site was actively occupied during that period; 'D' means it was not occupied (e.g., the colony died); 'Z' means the nest site was destroyed; and a lowercase 'a' means the nest site was inferred to be active, even though it was not directly observed (based on logical deduction from adjacent active periods). |
Note: Blank cells and "N/A" cells indicate missing data or inapplicable.
