The BeeBIT team wishes you a happy new year 2020!
Since the start of the project in 2013 a lot of work has been put in development and operation of the eHives. In 2015, the first eHives were shipped and the association »BeeBIT e.V.« was founded. Our database is growing daily ever since. As the decade ends, we had a brief retrospective of 2019 in mind to thank the people and institutions that are working with our/their eHives. Enjoy the following text and make sure to check out the supplementary materials!
The aim of this blog post is to show a huge amount of data (often more than 60 MB per eHive) in a figure that is small in size and reasonably easy to understand. We picked eHive AUT-BIE-1 as an example because this hive collected data over the whole year 2019 without interruption. However, other eHives with enough data were not ignored and a figure similar to the one shown beneath was created and can be downloaded from our website, c.f. supplementary materials at the bottom of this blog post.
Don't worry, the following figure is explained in detail in the text underneath.
The data from the temperature sensor of the weather station (as well as all other data shown) was downloaded from the website's diagram viewer and averaged over 24 hour long intervals. The calculated daily mean is plotted as a line graph where the lines connect daily mean values (365 points) and are colour-coded according to the mean value of the two connected points. The colourbar is shown on the right. On the x-axis the beginning of each month is labeled for better orientation. Dates were calculated using local summer time (that is UTC+2 for Austria where AUT-BIE-1 is located).
On a second y-axis the solar irradiation is visualized in a bar chart. Please note that since we calculated daily mean values, the irradiation during daytime (especially at noon) may be considerably higher.
The temperatures inside the eHive are visualized as one block consisting of 365x6 colour-coded tiles (365 days and 6 sensors). The same colourbar as for the outside temperature is used. This approach makes it easy to track the colony's position inside the hive just by looking at the colour of the tiles: If we take a look at the months March and October, we observe that the colony moved from between sensors 3 and 4 in March to sensors 2 and 3 in October.
The breeding temperature of a bee colony is circa 35 °C. We can use this information to track when and at which position inside the hive the colony might breed. Therefore, we visualize the deviation from this target temperature. Of course, we have to use a different colorbar for this task. If the deviation is small for an extended period of time, it is very likely that we found the breeding combs. In our example breeding begins around the midst of March and ends mid-August to September.
In the last subfigure, the hive weight is shown in a line graph. The 365 mean values are connected by colour-coded lines. The colour corresponds to the weight change rate between two connected points (and is therefore a measure for the line's inclination). Again, the colourbar can be seen on the right. In the data, some jumps with a change rate of more than 1 kg/day can be seen. Most likely, this is a result of the beekeeper's work, e.g. adding or removing a honey shroud. A sudden drop in weight (especially during summer) might also signalize a swarming event.
On a second y-axis the rain rate is visualized in a bar chart. Please note that mm/day is equal to litre/(m² day), using 1 litre = 1 dm³. By taking a look at the beginning of June (around the 6th or 7th), one can see how extensive rainfall leads to a decrease in the weight change rate.
Data from the following eHives was visualized:
DEU-DHG-1, DEU-FKG-1, AUT-WIS-1, AUT-BIE-1, DEU-MNG-1, DEU-OEG-1, DEU-FDG-1, DEU-LPG-1