Figure 1 : Hive weight data from December 2020 . System 14 is represented by the colour blue and System 15 by orange .
Figure 2 : Weight data of two hives for January 2021 . System 14 is represented by the colour blue and System 15 by orange .
keep themselves warm , and the fresh nectar loses weight because of evaporation . The occasional sharp changes in the weight are caused by the beekeeper undertaking hive manipulations . The natural weight variations within a day indicate healthy foraging activity for first 10 days as both the hives gain weight . After the increase around 10 December , both colonies maintain their weight which indicates that the foraging was just enough to sustain the nectar / pollen reserves in the hive .
Trend in weight change
For the month of January 2021 , the long-term trend in weight change of the same hives in Figure 2 tells a more interesting story . The hive with System 15 starts the month with a net weight of 45kg , and by the end of month has a weight close to 65kg . Whereas the hive with System 14 has a weight of 48kg at the start of the month , and 57kg by the end . The weight change of a hive over a period of time is the net result of increase in the number of bees in the hive , as well as the stores of pollen and nectar . Even these two parameters are related as only a hive with access to adequate pollen and nectar is able to grow in numbers and sustain a bigger bee population . This makes it clear that bees from hive with System 15 visited significantly more flowers and contributed more towards pollination compared to the other hive .
Measuring hive weight
Monitoring the hive weight , with its daily variations as well as long-term gains is a very good measure of its contribution towards pollination . Measuring hive weight , however , has its own set of challenges . Beehive weighing scales are cumbersome and do not facilitate rapid deployment , especially when movement of hives from one field to another is required . Harsh weather conditions can significantly impact the performance of these scales . And the most
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