Hello readers,
Last Read and Write I commented on a report from Honey Bee Valley co-worker Dries Laget. A project where they use Arnia hive scales and monitoring systems to collect data and draw conclusions from that data. The report from last time was released shortly after the implementation of the project, and at the end of that I wondered if I could find any follow ups.
As I am all over the place when looking for new information I had no clue where I found that report. Maybe it's an idea to take notes on what my sources are for future reference. That being said, I started my search on the Honey Bee Valley Website, a site packed full with information about bees and plants that are good for pollinators. A site that is still growing! But I didn't find what I was looking for. So not to waste too much time I drafted up an email and sent that to Dries asking him if the follow up reports were 'free to acess' and where I could find them.
The day after I received an email directing me to those reports, you guessed it, on the very website I was looking for them... (facepalm myself much?)
First follow up, shortly after the first report from september, there's one from october and november.
The first difference is that now 28 of the 35 systems are up and running (instead of the 22 from last time). The trend that started in september continued till october 25th (flow was on even though it's supposed to be fall here). A little side note to that is for some data only 20 systems were used (as the others were not active during some periode)
The most important conclusion remains: beekeeping is local. Out of 20 hives 5 lost weight where the rest gained weight through influx of nectar, in 2 hives there was an influx of more than 16 kg! On average the overall influx was around 4,5 kg.
A second observation is that after a periode of bad weather, when the bees can go out again, there is a drop in weight. The hypothesis is that this weightloss is due to bees dying. In one hive the loss was
2,5 kg, and that hive is no longer alive...
What the monitoring system fails to do is letting you know with absolute certainty when the queen stops laying. The sensor you put inside the broodnest is stationary, so when the broodnest shrinks down, the sensor could very well be outside the brood, making the measurments unreliable. The advice here is: after a night with frost, it'll take 3 weeks to be sure there is no brood left in the hive.
You can combine the data from the sensor with the weight of the hive to see if the colony is still alive. Fluctuating temperatures with a steady drop in weight shows the bees are still alive. This fluctuating temperatures with an even, unchanging weight tells you that hive is dead.
The next report looks at november 2018 to march 2019. For some reason only 18 systems were operational during that time (dead hives?)
The winter was rather warm for our climate, this means pathogens have an easy time surviving. This is disastrous in bigger colonies, as the pressure put on them is bigger. The smaller, weaker hives, that might have died if the winter was harsher, took advantage of rising temperatures early in the year to find extra resources sooner than normal and thus they were given a boost, instead of collapsing.
The report doubles back on the difficulty to determine when the colony no longer has brood, as this is input you want to know when you want to treat for varroa mites. The sensors did see that some beekeepers did an oxalic acid treatment in december, which in hindsight was too early. In fact the data in some hives suggests there was no broodless periode at all.
In the hives were broodbrakes did occur the queen started laying again early in february (around the 12th) as the temperatures started rising above 12°C at that time.
The switch in winterbees to summerbees is not visable in the data, it happens too gradual and with other things going on (cleansing, gathering of resources...)
Looking at the data from individual systems the corrolation between the local weather and how the hive fares is clearly present.
Winter stores were used up faster by smaller colonies, as the bigger colonies have more bees to keep the temperatures in check. But overall the average use of stores can be noted as 66g per day (give or take 18g). The consumption of stores increases the moment the queen starts laying again, an observation that is easy to explain as generating heat requieres consumption of sugars.
Suppose the queen would continue laying during the winter, the consumption would raise to 120g per day!
Cleansing flights! You may not expect this, but the cleansing flights show up in the data. The first few days of good weather, the weight drops with this as the only explanation, the drop in weight continues and one could say the cleaning in the hive also is part of this data, and this is very plausible, but the first few days of nice weather does point towards cleansing flights.
Next we have the start of the spring; march and april 2019, again with 22 systems in operation.
The data shows we did not have a good spring time. Every couple of good days, with hives collecting resources and increase in weight for the hive were interupted by a day or a few days of bad weather and consumption of what was brought in, or what they had left from winterstores. It is only starting from 16 april that the real 'spring' started for the bees, but even that early start was again interupted 10 days later.
Weightloss during the night shows how many nectar vs the amount of pollen was brought in. Higher loss of weight means more nectar was brought in, as the water is vaporised from the nectar during the night. Hives that gain weight during the night are affected by the weather, moisture is absorbed in the wooden hives, adding to the weight.
First weightloss in the morning is tied to the outside temperature; 12°C -15°C is the starting signal for the scoutbees to leave the hive. If the drop in weight is significant and takes a while to climb back up, this is an indication that the landscape does not provide for the bees and they have to fly to far to be effective. The data collected shows the diversity in the landscape, the north of Belgium is better for the bees during spring. West- and East-Flanders have not much to offer to the bees, according to the arnia monitoring system.
The final report that is up looks at the remaining months up until july 2019. The amount of monitoring systems used now is very diverse. Batteries running out, problems with connections and other problems took some systems out of commision.
The data is also difficult to interpret as the beekeepers go into their hives and are managing their bees, the notes they took didn't always explain what the readings after the interventions meant. But one observation can be made: it is only when temperatures start hitting the 20°C that the increase or stability of the hive-weight starts. Unfortunatly the year 2019 was not the best year for the bees. After a good periode of flow, and harvest for some beekeepers, there was a setback in weather conditions, and beekeepers hade to give back to the bees as the stores started to decline as bees needed the resources to survive.
One hive, where the beekeeper reported a swarmcells, the hive did not swarm but the data shows this internal switching of the queen has cost 16 kg of honey.
A stop of nectar flow is an annualy recurring aspect in Belgium, in the end of may - beginning of june it's waiting for the Tilia trees to start flowing. In 2019 this was a short break as from 17 june you can see the bees bringing in more nectar again. Even though this was a short periode, the loss in weight per hive has an average of 8,2 kg!
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So what do these reports tell me? In my opinion this data could be usefull for scientists, but not so much for the beekeeper himself. Maybe, in the future, when these measurements are wide-spread and projections can be made into the future this will be viable for beekeepers too. But as it stands, I believe the beekeeper has to know his bees and his environment. As a beekeeper you want to know when to do what, as putting supers on too early can have a devastating effect, but putting them on too late is maybe even worse. So as long as these monitoring systems are uncapable of giving you a heads up; Saying it's time to do this or that, I don't see them being used all that much, especially if you look at the prices of these things.
It's ok if you're tech savy and you only have a couple of hives, but I don't see myself purchasing a base for 10 hives each...
The report itself is also clear that some readings have to be accompanied by the notes of the beekeeper, they have not much value if you don't know what's happening in the hive at that moment, or what the weather is like...
We'll see what my BEEP-base brings me ... (Not an Arnia system, but simmilar)
Bob Out
-I did not proof read this, there could be a lot of spelling mistakes in here, sorry for that! -
