Cost-effective measurement of honey bee hive weight as a measure of pollination success
By Omar Anwar ( PhD Candidate at University of Western Australia ) and Liz Barbour ( CEO , Cooperative Research Centre for Honey Bee Products )
WITH flower pollination being a significant factor affecting almond crop yield , growers are continuously looking for methods to measure honey bee hive health and performance . This is where electronic monitoring of beehives may be able to play the important role of gauging the contribution of each hive towards pollination . A recent PhD project at the University of Western Australia , funded by Cooperative Research Centre for Honey Bee Products ( CRCHBP ), focused on designing and delivering ‘ Smart beehive monitoring for remote regions ’. Multiple beehive data acquisition systems were developed and deployed to collect sensor data from beehives with the aim to improve the communication aspect of these electronic systems for better remote deployability within Australia , and to reduce the upfront and running costs of hive monitoring .
To meet these project aims , this required careful selection of sensors to keep the power consumption low and minimise the data generated by the sensors . With a low data rates , the latest NB-IoT communication for remote deployment could be used . Hive deployments during this study were across the south-west of Western Australia , where the honey bees collected pollen and nectar from a variety of floral resources . Temperature , humidity , atmospheric pressure , CO2 , acoustics , vibrations and the weight data from the hives was collected every 10 minutes . The location of hives was used to collect the weather related data such as external temperature , humidity , rain and wind speed from Bureau of Meteorology ( BOM ). All this data provided useful insights into daily bee activity , their foraging patterns , and the productivity of the hives . Between December 2020 and January 2021 , two of these data acquisition systems were deployed in hives placed in clover fields owned by Bell Pasture Seeds at Capel , WA . Due to the surrounding bush flowering , the colony was mostly restricted to clovers for foraging . Data collected from hives during this period shows a strong correlation between hive weight and the bee foraging .
Impacts on hive weight
Figure 1 shows the hive weight data for two systems , System 14 and System 15 for first half of December 2020 . The dips in the hive weight each morning are caused by bees leaving the hive in large numbers in search of pollen and nectar . The magnitude of these dips is dependent upon two factors , first is the number of bees in the hive , and second is the availability of foraging resources . When early-morning scout bees find good pollen and / or nectar , they return to the hive and use waggle dance to communicate the location of the resource to other bees . This triggers a massive outflow of honey bees . The weather conditions also play a role , and bees prefer to stay inside the hive if it is too hot or too cold outside . On a typical day , the hive weight increases when bees return with the pollen and nectar , with evenings as the most productive part of the day ( increase in weight ) during this experiment . The hives lose weight at night as the bees inside the hive consume food to
36 In A Nutshell - Spring 2022 Vol 23 Issue 3