Brood volume and winter cluster
Bees expend a lot of effort in raising more bees, and bee brood volume is an excellent measure of colony health. Fortunately, bees maintain their brood at a constant temperature, 35C (95F), so brood volume is easy to measure with a matrix of temperature sensors in the brood box. The more sensors placed in the brood area, the more accurate the estimate of brood volume can be.
Temperature sensors placed in the area where the bees will cluster and consume feed in winter will also allow beekeepers to follow the size, shape, and movement of the winter cluster.
At this time, we are unaware of any temperature monitoring effort that provides a brood volume measurement, or a more precise characterization of the brood situation. We are also unaware of any similar effort to monitor overwintering progress. However, several beekeeping technologists have installed one or two temperature sensors in the brood nest.
Websites reporting simple brood area temperatures include:
A somewhat more complex approach is found here:
- Michael Mietz’s Colony Monitoring Project (in Germany, website is in English) This site has animations showing the placement of an array of temperature sensors in the brood area and further animations showing patterns of temperature change – indicating brood volume, or cluster position – over time, in both summer and winter, as well as capturing the swarming process and the disturbances caused by treating for mites. From this research project it is possible to imagine a commercial version of a sensor matrix that reports brood volume in the summer and cluster size in the winter.
A device for researchers, one that monitors the temperature in many cells, is described in this article in the Apidologie journal:
- A new device for continuous temperature measurement in brood cells of honeybees by Matthias A. Becher, Robin F. A. Moritz, Apidologie, Sept 2009
The utility of a single temperature sensor above the brood nest is described in this article available for purchase, which has an excellent reference section, many available online:
- Temperature changes above the upper hive body reveal the annual development periods of honey bee colonies by Egils Stalidzans and Almars Berzonis, Computers and Electronics in Agriculture, January 2013