Fig 1.
Experimental setup of the apiary in Uddevalla.
A Radio Frequency Identification Technology system was installed at each colony to track tagged bees’ activities. Bees were tagged with passive ultra-high frequency tags for the experiment in the first four hives from the left in A) and in the first four hives from the right in B). Each hive entrance consisted of an open tunnel system with integrated antennas recording the direction of movement of a tagged bee, as shown in C). An example of a tagged drone is shown in D). The weather station was placed in the middle of the apiary. Picture A) was taken on 23rd of May 2022, B) on 24th of June 2022, C) on 26th of May 2022 and D) on 18h of May 2022.
Table 1.
Behaviour interpretation in terms of the length of flight categories.
Fig 2.
Effect plots of the covariances used to determine differences between Buck and Mel drones.
The effect of A) age, B) temperature, C) light intensity, and D) wind speed in interaction with subspecies on the number of hourly registrations for Buck and Mel drones. Mel showed significantly higher hourly counts with age compared to Buck [Buck: hybrid Buckfast, Mel: Apis mellifera mellifera].
Fig 3.
Kaplan-Meier survival curves of drones.
A) Buck drones’ survival in spring (light blue) and in summer (dark blue), B) Buck (light blue) and Mel (dark blue) drones’ survival in summer. The survival curves were compared with the log rank test. A significant difference between the survival of spring and summer Buck drones was found. No difference was found between Mel and Buck drones in summer [Buck: hybrid Buckfast, Mel: Apis mellifera mellifera].
Fig 4.
Age at first registration (days) and lifespan (days) of Buck (light blue) and Mel (dark blue) drones tagged in spring and summer.
The size of the points is based on their occurrence in the dataset (i.e., the larger the point the more occurrences) [Buck: hybrid Buckfast, Mel: Apis mellifera mellifera].
Fig 5.
Relative number of Buck (light blue) and Mel (dark blue) drone registrations in spring and summer.
Relative numbers are here presented as the relation between the number of registrations per hour to the total number of registrations. Mel showed a later peak activity than Buck in summer. [Buck: hybrid Buckfast, Mel: Apis mellifera mellifera].
Fig 6.
Correlations of the daily number of registrations against environmental parameters.
Daily spearman’s rank correlation of the number of registrations of A) Mel and B) Buck against temperature in red, light intensity in blue, wind speed in green and rain sum in purple. The boxplots at the bottom show the median (line), interquartile range (box) and the top and bottom one percentile (whiskers) for each weather parameter. Outliers are marked with black points [Buck: hybrid Buckfast, Mel: Apis mellifera mellifera].
Table 2.
Differences and similarities between Buck and Mel drones in summer.
Fig 7.
Kaplan-Meier survival curves of worker bees.
Worker bees’ survival A) in spring (light orange) and summer (dark orange), of Buck (light orange) and Mel (dark orange) in B) spring and C) summer. No significant difference between the survival curves was found with the log rank test. [Buck: hybrid Buckfast, Mel: Apis mellifera mellifera].
Fig 8.
Age at first registration (days) and lifespan (days) of Buck (light orange) and Mel (dark orange) worker bees tagged in spring and summer.
The size of the points is based on their occurrence in the dataset (i.e., the larger the point the more occurrences). All worker bees with registered activity within the first four days of tagging did not show further registrations. [Buck: hybrid Buckfast, Mel: Apis mellifera mellifera].
Table 3.
Differences and similarities between drones and worker bees.