Understanding what conditions are optimal for honeybees seems to be a lifelong quest for me and during our winter season, there is time to do a bit more research.
Plus for a Christmas gift my daughter gave me the most exquisite gift…a remote monitoring via Wifi weather station that includes an app that can be downloaded onto the my cell phone. So each morning when I have coffee, I log on to the data to see what the humidity and temperature readings are inside my beehouse where I have 20 hives wintering.
I’m trying to establish some optimal temperature and humidity levels inside the wintering beehouse…especially with reference to brood rearing initiation. But I’m looking for information that represents hives not necessarily being kept indoors.
Have any of you beekeepers in various parts of the world charted humidity levels inside your hives during winter or summer conditions that you would care to share? Or have you come across some scientific research that you could post the link to?
I have an Arnia hive monitor, which is currently not working after it got soaked in a rain storm last year. However, when it did work, the brood nest humidity was reliably between 40 and 60%. I think @Webclan has a couple of Arnia monitors too, so she may be able to give you some Australian data. You could also ask the people at Arnia. They are slow on communications, but very nice, helpful people. https://www.arnia.co.uk
F. Battalov did extensive research on the subject. He was measuring humidity between frames in hives made of 2 boxes of 12 frames. Summary of data he published (1959):
Spring and autumn in absence of honey flow - humidity around 88% (76.6-91.1%).
In time of strong nectar flow humidity drops to 54-66%. Strong colonies keep humidity below 55%. Week colonies - below 65.6%.
General idea: bees keep humidity quite high in usual circumstances but drop it in case of strong nectar flow to facilitate evaporation of excessive moisture from nectar. Strong colonies are more efficient in humidity regulation. There could be serious deviations from the norm but they do not last long.
I’ve run temp humidity probes for a few seasons between brood frames and between honey frames. The humidity of brood frames where more stable in the brood than else where in the hive. I’ll dig them out and post them for you. My info correlates with the paper ABB cites.
Thanks for those numbers and Arnia’s link…when I factor in the temperatures with those humidity levels I get a true picture of the moisture available to the bees. So for the fun of it this morning I got the temperature and humidity levels at Orland, California…that area of California (including Chico & Redding) used to supply packages to this part of the world. The temperatue was 8C and the RH was 54% in Orland…and if you look at my beehouse temperature and humidity data from yesterday posted below, it is almost identical. The bees appear to be controlling those temperatures and humidity levels. From your observations and what you have heard of happening, do the bees brood all winter in your area?
ABB Thanks for posting that research by F. Battalov…have you ever checked your hives during mid-winter for brood rearing in Australia…& pre-Australia? I think you will find the charts below interesting.
AdamMaskew Here are my temperature and humidity trends for yesterday that you may find intertesting…not inside the hive like yours but inside the beehouse (super-hive equivalent…they control ambient conditions inside the beehouse) while the outside temperature was -15C…you can see the ventilation fan starting and stopping. Notice how quickly the temperature and humidity rebound after the fan shuts off.
Yes, I have nice frames of brood even now. They shrink the nest size down to about 40-50% of peak season, but the queen lays all year. She stops laying drones in about August/September, then starts again in late December/early January.
That is very interesting. I bet if you had probes between the frames your results would be very different.
Here is the data from three temp/humidity probes in a long Lang in Western Australia over a year period Oct 18 to Oct 19. You can see the difference in the honey (flow frames) and the two brood locations. I’ll find a photo of the hive so you can see where the probes are.
Hi Dawn.
I had 2 Arnia gateways , but both failed after just 2 years. So now I’m out of pocket for quite a number of scales and sensors that don’t give me any readings. I’m basically offline.
After what I paid for the whole thing, I’m quite upset.
But the Arnia team promised there will be a replacement.
Hope soon.
Where I live currently winters are mild and brood rearing never stops, but it goes on reduced scale. Here is a graph showing high/low temperatures from the last winter:
Before, where temperature was falling below -20°C and -30°C on occasion, I don’t think there was any brood rearing at all. But I never had a chance to open a hive to check personally. Hives were stored in small holiday house and temperature inside was not much different from outside. It was more for protection from wind and more stable environment.
By the way, side effect of such storage was winter part of varroa mite management. We were covering room floor with thin layer of wood shavings mixed with wood-tar creosote. About 2 table spoons of creosote prepared as water emulsion before mixing with shavings per ~30 square metres of room. The purpose was to deter mice. Not sure about mice, but it caused massive death of varroa mites and very healthy colonies by spring time.
When swept up in the spring, that would make fantastic smoker fuel!
In the UK, I used to use corrugated cardboard soaked in creosote and dried as rolled up cylinders. It burned for ages, and the creosote had a kind of sedating effect on the bees. Maybe that is why we never had varroa problems in the UK, on the other hand, it was 25 years ago, and varroa was not such a big deal at that time in my region.
The problem in the US is that you can’t get pure creosote, it always has fire retardants and other junk… Sorry for rambling on, but I enjoyed the nostalgia, thank you!
Great info AdamMaskew…your data shows the range of broodnest relative humidity that doesn’t fluctuate much…indicating to me the bees’ comfort zone. Could you give me a typical temperature for the brood nest during mid-winter?
@Doug1 I’m not sure I get a real winter when I see your photos and listen to your management issues. A cold day for us is a minimum over night of 2 or 3oC with a day time max of 8oC.
My winter and summer brood nest temps are the same 35-36oC. I don’t get a brood break, the brood just shrinks to a few frames. If you look at the screen shot with the temp info that is what I see in Winter. But on only one of the brood nest locations (#2), near the hive entrance.
