Hive sensors, some cause and effect

We had problems with the original broodminder unit set into the hive on the scale last fall, the issue was batteries going dead in a couple of days. The weather turned cold and I stopped trying to deal with that problem, we had reached the time of year where we dont want to open hives anymore, bees have the propolis seals in place for winter and I dont want to break those seals at that time of the year. Earlier this week we had some nice weather, and on Monday we got out to do the first spring look at the bees. We popped the lids off of all of them, put on the first round of spring supplements, and while we had the lid off of the scale hive, I replaced the temperature and humidity sensor. So far, the replacement seems to be working much better, battery levels are reporting consistently in range of 87%. By Thursday the snow had melted enough I could get the lawn tractor into the back lot, so we took the chance to do a round of oxalic acid vapor to try knock down the mite population before the spring brood starts in earnest. When we fed the bees, the pollen supplement went directly over the cluster and the temperature sensor right beside the supplement. I watched the graphs for a couple days, and the data looks good this time around, consistent measurements. The Broodminder is set to take a reading hourly, and it is providing temperature updates every 58 minutes like clockwork. The data proved to be very interesting, with definite patterns. The sensor went in on Monday, and thu till Friday we can see that the internal hive temperature is slightly above outside temps, and goes up and down with the ambient temp. On Friday this changed. Through the day on Friday the internal temperature went from around 15c strait up to 30c, which is approaching brood incubation temperatures, and it did not take the big drop overnight like we see on previous nights. BroodStarting We normally see brood starting in early February, this winter has been much colder than years gone past, with hives buried in snow last week. But the internal temperature is fairly definitive this morning, the bees have started to incubate brood. The 2017 bee season has begun in Campbell River. The question to ponder this morning. We put supplement on the bees on Monday, they have started to incubate brood by Friday. Is this a cause and effect relationship, or, is it just the normal time of year for them to start brooding ? As an aside, the hive weight graphs are a bit skewed right now, but we did learn something interesting in the process. Last week the snow just dumped on us, it just kept on falling. At the peak, scale showed there was almost 80lb of snow sitting on top of a beehive. On the bright side, nature’s snowplow (rain) made it go away as fast as it came. There is a dramatic weight loss on the hive scale on Monday morning, that came about as we swept the remaining snow off the covers when lifting lids to check the bees. It was a nice warm day, the bees were flying, and we saw endless yellow spots on the snow as the bees got out to relieve themselves. That was a sure sign the bee season is about to begin, and the sudden increase in brood nest temperature is a confirmation, bee season has started.