Thanks, gents. Michael, that was the kind of info I was looking for; what a fascinating article. Center of cluster temperature is basically maintained at ~94F even in the coldest weather. Ian, read the article referenced in Michael's last response; it refutes what you were told about the cluster temp.
Michael, you and I were using "matters" in different ways. I understand now that you were talking about practical considerations with the bees. I was talking about understanding more about these little critters and better appreciating how it is that they survive, when they survive.
Many thanks, again.
>>Ian, read the article referenced in Michael's last response; it refutes what you were told about the cluster temp.
I have read the study, actually I posted it to this fourm from the Bee-L disscussion fourm. It is alot to go through, but full of very interesting info on cluster temps through out the winter. I found it very facinating to read. Maybe you should read it again,
The study is done in a cold wintering climate. The honeybee holds cluster at 23degreesC from Nov through Feb regardless of the outside temp. It rises to 31degreesC in March when brooding starts. www.beesource.com/pov/usda/thermology/fig4.htm
[This message has been edited by Ian (edited February 10, 2004).]
Ian, I've looked again at the article. Fig. 4 pictorially demonstrates their description of the cluster changing positions within the hive during the winter months. If you will look again at Fig. 2, I think you will see that even in the coldest temps (7F for the data of Fig 2) the center of the cluster was kept at 94F. Figure 4 doesn't show the temperature at the center, and presumably uses only 3 isotherm lines for purposes of showing the cluster's position changes because no more data than that was necessary to effectively make the point.
Whether you agree or not, many thanks for posting the article in the first place.
David in Baltimore
Perhaps, but usually all data is shown when drawing conclusions, and this is a study on wintering bee cluster throughout the winter. Why show the increase in temp in March and no other month.
Maybe I"m miss interpereting the data, but it follows the knoledge that has been given to me else where. I have never tested cluster temp in the hives through winter,
Anyone else here interperet this info as I did? Im going to look at the data again...
Fair points, I agree. But look at figure 4, note how large an area it is that lies within the warmest isotherm (closest to the center of the cluster), and note how quickly the temp increases over such short distances when moving in the diagrams from one isotherm to the next one moving closer to the center of the cluster. I think you'll have to conclude that they simplified the diagrams b/c their point in Figure 4 had only to do with cluster movement rather than the specifics of temperature maintenance within the cluster. It would be hard to believe, especially given the data in the earlier figures that the temp within that warmest-shown isotherm was uniform.
In any event, you've taught me a remarkable thing about wintering honey bees with this paper and this discussion, and I'm grateful.
David in Baltimore
It looks like I am right out to lunch. I looked over the study and,also looked for back up else where last night and found nothing to back up my previous statement. My beebible talks very little about wintering temps, and my other local bee management book stated a slight difference in winter clustering temp through out the winter period, but nothing even close to what I boasted.
I have believed the change in cluster temp right from my beginnings in beekeeping. Well, you can learn a new thing every day, and I guess am one step closer to beeing one with the bees...
I think I have to agree, they simplified the data inthe diagrams.
[This message has been edited by Ian (edited February 11, 2004).]
I can feel the difference on the glass surface of my observation hive when they start rearing brood. It's noticably warmer. There will be bees just as thick in other places but not that much heat.
I think you were not that far off.