When do bees die from cold?

[ArmucheeBee]

Please excuse my ignorance, but we do not have the degree of cold some of you have.  My question is:  with it going down to -46 in Minnesota last night, will that not freeze a cluster solid?   Could some of the Minnesotans respond?   I get worried about the bees here when it gets under 20F.

[iddee]

A large cluster can survive it if they have the food available.

[ApisM]

I live 8 hours north of Minnesota, and we think N. Minnesota is warm.  We have -40 for several weeks sometimes up here.

The key is to have plenty of food (60lbs), and make sure they have a vent.  Cold does not kill bees!  It is moisture and no food.  Wrapping them is very helpful to.  I usually bury my hives in the snow with vent holes (usually you don't have to bury them, the snowfall just does it for you).  Make sure you allow the proper vent hole to be unobstructed if the snow covers it.  Usually I have 100% success rate.  I don't have mites here in this part of North America yet.

Cheers

[AllenF]

The cluster makes its own heat.   Bigger the cluster, more heat they can make.   But they burn more food with the more heat they make.   Skip ahead and look at about 4 minutes on the video. 
Bee Vision and Heater Bees

[Michael Bush]

The severe cold will kill a small cluster sometimes.  A larger cluster usually does fine.

[FRAMEshift]

The video mentions at 6:25 that incubation temperature controls whether a bee becomes a house bee or a forager.  This seems to contradict all the research I've read about individual bees moving from one role to another as they age.  Anybody know a credible reference for this stuff, or is this just garbage?

[T Beek]

That's one of the coolest vids ever 8-) 8-) 8-) 8-)Spectacular!!!!

FRAMEshift, for answers to your Q, check out BeeNatural site/heater bees.  Dennis did a pretty good job on the essay.  And NO its not just garbage, its science, we/humans don't know nearly as much as we think we do about many things, including honeybees.

thomas

[BjornBee]

Those cold temps will take it's toll.

Hives with not enough fall brood raised last September and October, will have lost their older bees by now. Making smaller than usual clusters vulnerable to extreme temps. Also bees with disease and other issues will die for reason of extreme cold or long cold snaps. Many old advice simply stated that "cold does not kill hives". And that just is not true. It may be for many reasons leading up to it, but cold will kill weaker hives. That's called mother nature taking out the weak. Something most beekeepers do everything in their power to stop. Which is not always a good thing.

[FRAMEshift]

FRAMEshift, for answers to your Q, check out BeeNatural site/heater bees.  Dennis did a pretty good job on the essay.  And NO its not just garbage, its science, we/humans don't know nearly as much as we think we do about many things, including honeybees.

thomas

Thomas, I agree, that's a very cool video.  Excellent quality photography.  I read Dennis's essay but it does not address the issue of temperature regulation of the role of bees.... whether they will become house bees or foragers.  If this is real science, where is it documented?  My search so far has not found any scientific references.

Oh, I must say the Bee Natural site has been totally revamped since the last time I looked at it.  Dennis's exhaustive work is what convinced me  some time ago that natural comb / foundationless was the way to go.

[T Beek]

Those cold temps will take it's toll.

Hives with not enough fall brood raised last September and October, will have lost their older bees by now. Making smaller than usual clusters vulnerable to extreme temps. Also bees with disease and other issues will die for reason of extreme cold or long cold snaps. Many old advice simply stated that "cold does not kill hives". And that just is not true. It may be for many reasons leading up to it, but cold will kill weaker hives. That's called mother nature taking out the weak. Something most beekeepers do everything in their power to stop. Which is not always a good thing.

Thanks BjornBee, I knew you were a "let em die" advocate, but it don't make it any easier.

FRAMEshift; please let us all know what, if anything, you find out.  I've been turning beeks and friends on to this vid ever since I saw it, hate to be sending bad science out.

thomas

[FRAMEshift]

Thomas, I knew I had seen this before.  It comes from Jurgen Tautz, a professor at Wurtzburg University in Germany.  The video is from Richard Hammond's Invisible World and was shown on BBC One on March 23, 2010.  Tautz wrote a book called "The Buzz about Bees" which also has great pictures and advances the idea that bees are a superorganism that controls it's own internal development in order to reduce resource consumption. 

I still have found nothing I could call science associated with this.  Tautz's website has been closed down (it says until July 2011.)    I would say there is nothing new about the idea that bees generate heat by flexing their flight muscles.  What would be new is the idea that there is a special class of bees that do this.  But I have seen no real evidence that there are "heater bees" that are different from other bees.  And the thesis that small changes in temperature determine whether a bee will be a forager or a house bee is in contradiction to much research showing that bees move from one role to another during their lives. 

Here is an article on Tautz's claims (http://www.telegraph.co.uk/earth/wildlife/7435950/Honey-bees-secret-world-of-heat-revealed.html).  Notice the statement near the end:
Professor Tautz has asked us to make clear that the temperature changes brought about by the heater bees alter the probablity of the tasks that will be performed by larvae when they mature.

There is something that does not smell right here.  Maybe it's a case of journalistic exuberance, trying to create excitement for stories.  Maybe there is some real research behind this and not just an attempt to make money by selling a picture book.  So far I haven't seen it.

[jhs494]

FRAMEshift,
 There is an article in January 2011 Bee Culture about this hive thermoregulation and the role of the heater bees. He also, within the article, references to many sources for his information.( written by Clarence Collison, Audry Sheridan)
 In rereading this article I don't see where the role of the heater bee is limited to only certain bees but rather a step in the bees age or development.   references to (Stabentheiner et al. 2010)

This article is excellent! Once I read it I search for more info on thermoregulation in honey bees and came across the video.
This video left me the same as you, not quite sure about its accuracy in with regards to heater bees and how they become heater bees.

[FRAMEshift]

I would like to believe that Tautz is for real.  He has a long record of publication on insect biology (most of it in German).  But these recent claims about bee behavior are amazing.  How does he measure which cells in the hive are at which temperature and how does he know what the probabilities are that this changes the role of a bee at maturity.    Many studies using paint dots have shown that bees change from one job to another as they age.  Tautz seems to be saying that bees are programmed for one job.

Here are some other claims.  I wonder how some of these things can be determined:

Bee orientation flights are not for orientation but are practice flights for bees that will accompany a virgin queen on her mating flight. 
I thought it had been shown that the bees that are orienting are the ones that are moving from inside jobs to outside jobs.  And orientation flights occur when there are no virgin queens.

Bees turn off color vision as they are returning to the hive in order to save energy.
You might be able to determine that color vision is turned off, but energy savings seems an unlikely reason.... and how could you determine that?

Fascinating ideas but it just doesn't smell right.

[T Beek]

Thanks FRAME shift and jhs494 for the info and effort. 

Seems we may have "another" bee mystery on our hands. :)

thomas

[Finski]

.
 When cold kills the hive?

Normally food will be finish and then hive dies.

Poor insulation and wind via bottom or entrance add food consumption.

Too small cluster cannot stand cold. They must make too much work to keep themselves warm.

Outside my smallest colonies must be 5 frames of bees.
With electrict heating I may over winter one frame of bees.

It it better join hives before autumn that they are strong enough to stand the winter.
You may take brood frames from biggest hives to aid small nucs in late summer.

Does cold kill hives? - yes it surely does

if the hive has bad infestation of varroa, 75% of wintering bees may die when they emerge out. That makes the colony too weak and a beekeeper notes nothing. So I have lost 4 hives this winter. They seemed strong when I feeded them.

[FRAMEshift]

Here is an article on thermo-regulation.

http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0008967

[Finski]

.
In my country swarms' favorit places are brick chineys of houses. The house may be habited or nonhabited. However non of those hives survive over winter. Stone conduct heat so well that chimney is too cold place to survive.

[woodchopper]

Seems we may have "another" bee mystery on our hands. :)

Seems like the more I learn the less I know.

[FRAMEshift]

Ok, here is the article that was behind the mention at 6:25 in the video that incubation temperature of pupae causes different behaviors in mature bees.  So at least there is a real scientific basis for it, although I think the journalists who reported on it got carried away.  :-D

http://www.pnas.org/content/100/12/7343.full

[BjornBee]

Journalist comment to me upon my pointing out the false facts being reported on a particular story....

"Never let facts get in the way of a good  story".

Of course nowadays, most are just political hacks anyways.