temperature your bees cluster

Little John said:

But there's no box to tick for 'don't know, don't much care', or 'none of the above' or similar ...

Why on earth do you want to know what people's impressions are - as opposed to hard facts ? Or is that a secret for now ? Methinks this be psychology

LJ

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its always good to do a bit of surveying before you attempt to change the landscape.

derekm said:

No I 'm asking about your impressions of when clustering occurs and where you got the info from. not what Canadians do, I 've looked that up already in some detail.

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derekm said:

its always good to do a bit of surveying before you attempt to change the landscape.

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I`m off the hook

Mine are basically all over all the top bars still - they have only contracted into a ball the few times the temperature has been below 5 degrees. In the wooden hive this appears to happen a degree or so sooner than the polys. The bees have been noticeably more spread out in this hive since I replaced the conventional coverboard with a clear one and added insulation.

The reading on the thermometer above the top bars in my polynuc has been within one degree of 15 degrees pretty much all through Winter so far. We have only had a few frosty days though.

at 18C my bees are in full flight
at 15C my bees are in full flight
at 12c my bees are foraging at about 1/3 strength
at 9C there is a steady trickle of bees from the hive
At 6c just the odd bees flying
below 3C bees remain in the hive, but if you look under the hive through the open mesh floor, you will see the bees in a loose cluster , but slight movement around the cluster.
I really don't think our bees go into full winter cluster, where they are in a tight ball with little or no movement till it is about 0c

A lot of depend on the weather conditions. Take today for instance. It was 7'c and a bitter cold damp cutting breeze that goes straight to the bone, and not a bee stuck its nose out of the entrance .

It`s a great observation, Keith. I`m pretty much agree with that. It’s just important to remember that hive design and materials will also affect a state of a cluster IMHO.What are yours(wood/poly)?

mostly timber hives, but I have about 6 polys

I believe they cluster at 6c because this is what I have been told. Has this observed anywhere please?

I think that clustering is part of a much wider continuum. The ideal brood nest temperature is 34.5C but fluctuations in the region of 1-2C either side are tolerable. Thankfully, the ambient temperature rarely (if ever) gets to that temperature around here. Whilst the brood will generate a bit of heat for itself, this will be nowhere near enough to maintain a satisfactory brood temperature, even in the middle of summer.

Therefore I suggest that above 34.5C there will be some kind of dispersal behaviour, combined with a range of other cooling activities in the brood nest area. Somewhere just below 34.5C will initiate clustering behaviour in some (but not many) of the nurse bees.

These days, we believe that a great deal of honey bee behaviour is genetically hard-wired. Individual bees will initiate a particular behaviour when the relevant individualised environmental threshold has been crossed. The genetic diversity within a colony ensures that there is a tapered response to any stimulus. This avoids all-or-nothing responses that would be catastrophic to a super-organism that has to perform many different tasks concurrently. Furthermore, the magnitude of an all-or-nothing response to an environmental stimulus risks being too harsh: the colony would constantly have to counteract previous responses that overshot the desired goal!

I would have thought that, as the temperature falls further below 34.5C, the threshold temperature for clustering is crossed for more and more worker bees. Therefore the “cluster” gets more densely populated.

At what temperature are 100% worker bees in the cluster? Well, ideally they should all be in the cluster just before the ambient temperature is the same as the chill-coma temperature. Knowing bees, this temperature will be genetically determined and will vary slightly between colonies.

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My hives are in cluster when out temps have been a month around + 5C and nothing to pick from outside.

When hives make a winter cluster, they first stop brood rearing. They carry out last capper brood and fill the open cells with Sugar. They move food from coldest parts of the hive.

If I push a digital thermometer into the cluster, its temp is about 23 C.

When brooding starts in spring, colony has during cold night a tight cluster around brood.
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difficult to give an answer. some of my colonies do this some to that...

thenovice said:

difficult to give an answer. some of my colonies do this some to that...

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I agree, idepends on the size of the cluster. (if they have one) we've had frosts of minus 3 all this week. Some have clustered, some havent. I have a clear plastic frame cover, like many. Midday, when the sun is out and its a little warmer you can have a very quick 2 second look without them even noticing.

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Colonies are what they are in winter, and it is better to stay far from hives.
You cannot put them into cluster. If some one die, you get ridd of wrong genes. So simple.

And you can nurse bees without knowing in what temperature they over winter. France and Britain are easy
places to keep bees.

Further more, that knowledge you find from internet researches, but not from forum discussions.


Endothermic heat production in honeybee winter clusters.
http://jeb.biologists.org/content/jexbio/206/2/353.full.pdf