cluster movement?

[Papakeith]

At what temperature is the cluster capable of moving around in the hive?

How about with brood, without brood?

at -14 C  I'm temped to take some clear plastic and throw it over the hives to get some greenhouse effect going.

[blueblood]

I figured the cluster didn't move very much at all unless it was above the freezing mark without brood.  And, if the weather tricks the bees and brood is set, a smaller cluster warming the brood will stay with the brood and possibly die if they don't join the larger cluster after it turns freezing.  At least that's my take.  I would think it is hard to say for sure unless someone has opened the their lids in winter and exposed their hive to more harmful cold weather and observed the bees for movement.

[Jen]

My only thought on the clear plastic is that a green house effect causes moister, moister kills bees. My two cents 

[Riverrat]

at -14 C  I'm temped to take some clear plastic and throw it over the hives to get some greenhouse effect going.

I dont think you would gain much. The plexiglass is not a very good insulation source.  And if the temps in you area are as unpredictable as they are here. You might find yourself setting at work thinking about the solar wax melter you made if the temps should jump up higher than predicted.

[Papakeith]

agreed, that's why I'm tempted, but not doing! 

Although I've often thought that a low tunnel under the hive could gather enough heat to help the hives weather the extremes of winter up here a bit better as long as there was a method of evacuating the heat if it rose above a certain temp.

[Jen]

Keith-    I know you know this... but I've been taught with such care on this forum to not worry so much about the heat of the cluster, or how cold it is. It's the wind and moisture that will kill our bees. My2cents

[riverbee]

"At what temperature is the cluster capable of moving around in the hive?"
"How about with brood, without brood?"

pk, in general, ambient temps above 45 d farenheit will allow the cluster to expand and move to honey stores.
brood; bees will not abandon brood, and will sometimes die covering brood when the cluster expands and when temps drop in a cold snap in the spring.

if you have a copy of it, there is a good chapter on the winter cluster in 'the hive and the honey bee' on this, chapter 20 'wintering productive colonies'.
there really is more dynamics to the biology of the bee in overwintering, and they are more cold hardy than we think.

we have had about 50 successive days or more with sub zero temps, and brutal windchill factors, and my bees are still hanging in there.

[Ray]

ANYBODY have a source on cluster movements in the hive? I'm with blueblood I don't think they move at all when they have brood to protect and I think that is what kills some of the hives. Both of my dead out had frozen brood and starved bees with two inches of empty comb around them and honey just out of reach for the cluster.

[Riverrat]

ANYBODY have a source on cluster movements in the hive? I'm with blueblood I don't think they move at all when they have brood to protect and I think that is what kills some of the hives. Both of my dead out had frozen brood and starved bees with two inches of empty comb around them and honey just out of reach for the cluster.

What you are referring to sounds like cold starving. If it stays cold for an extended period of time to where the bees cant loosen up the cluster to get to stores they will starve

[riverbee]

"ANYBODY have a source on cluster movements in the hive? I'm with blueblood I don't think they move at all when they have brood to protect and I think that is what kills some of the hives. Both of my dead out had frozen brood and starved bees with two inches of empty comb around them and honey just out of reach for the cluster. "

ray, you yelling at us?........
chapter 20 hive and the honey bee; winter cluster

real quick:
Seasonal Cycles of Activities in Colonies

also i might have some articles from ABJ or Bee Culture..

[Ray]

Thank RB, I've got that book and actually read that chapter . The link helps too, but I was hoping for more.

[riverbee]

one bee culture article, read the full article here:

Wintering Beehives, Parts I & II


"Individual bees are cold blooded, but a healthy cluster of bees within a hive, with honey positioned correctly, has a great deal of control over its group temperature. As the outdoor temperature approaches about 55-57°F, depending on wind and sun conditions, bees within a hive begin to loosely centralize themselves near the bee nursery area (the brood nest) or near stored honey combs if the nursery has already been closed down for the season. As the day really cools to the 40s or so, bees will have clearly centralized themselves and will have begun to cozy-up. Colder still and the bees, just like our chilled, hypothetical human test population, will compact tightly. Some bees are in the interstices between combs while others are laying head first in empty cells. This tight configuration forms a solid, living cluster having roughly the volume of a soccer ball. The population at this point consists of adult worker bees, possibly some immature bees and the queen. No drones. They were all 'eliminated' during the Autumn and will be reproduced during the following Spring season. If baby bees are present, the nursery area will be kept at around 90-95°F while bees making up the outer layer will be nearer 40°F. If no developing bees are present, the center of the cluster will be around 70°F. Now suppose it gets really cold – down around 0°. Those bees making up the outer boundary get cold rear-ends, get agitated, and in their own bee way, begin to vociferously complain. This agitates bees that are closer to the center and that are warmer. All bees begin to flex (micro vibrations) their flight muscles, which increases the burn rate of their honey firewood, and the temperature of the cluster is increased. No honey = no heat = frozen bees. Every few weeks, a warm period is needed to give the cluster an opportunity to reposition itself onto more honey; carrying out the ashes is a human analogy for this. A bee cluster can withstand a bitter amount of cold for many weeks and survive very well. Indeed, the bee cluster may even survive better during a cold Winter. They live so closely that contagious Winter diseases can spread rapidly; however, some authorities feel that coldness suppresses bacterial spread."

"The cluster’s composition

Other investigators speculate that the cluster is simply a condensed environment that is controlled by temperature. On warm days, the environment is opened up and bees fly freely. On cold days, in an effort to control the temperature of the cluster, the large environmental expanse compresses itself into a volleyball-sized volume. Nurse bees and the queen are at the epicenter while house bees and foragers make up the insulating shell. It is as though the bees’ environment collapses on itself. It goes from being acres and acres in size to hardly 10 inches in diameter. Just as in warm weather when nurse bees make decisions concerning the nest’s temperature needs, nurse bees make the Winter temperature decisions, too. Said a different way, the bees cannot heat the ecosystem to 60°F, but they can form a cluster and heat themselves to 60°F."

ps ray, oops.....okay

[Ray]

Thanks RB (again) 
snip: "Now suppose it gets really cold – down around 0°. "
Isn't that a heat wave in your neck of the woods?

[riverbee]

pretty much ray, i don't think it's been above zero here for months......

here are a few more, some of my links were outdated, so i had to chase the articles down

The Thermology of Wintering Honey Bee Colonies
if you go over there, best come back otherwise we will send a posse after you to bring you back.....

The Biology and Management of Colonies in Winter

Endothermic heat production in honeybee winter clusters

[Papakeith]

thanks for the links. 
I guess I've got some reading to do before next winter.