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Author Topic: Population losses. Reposted to correct forum.  (Read 2770 times)

Offline ApisM

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Population losses. Reposted to correct forum.
« on: January 19, 2014, 11:04:49 am »
Hello,

Everyone always talk about winter losses, in regards to how many colonies perished during the winter.  My question is how many bees should one expect to loss during the winter.  For example, if I had 30,000 bees, when spring comes how many bees should be left when spring comes?  10,000? 5,000?

I live in the north where our temps go to -30 quite frequently, and lose alot of bees, due to them flying out on the sunny days.  The warmth gets them active, but when they fly out of the upper entrance the cold instantly freezes them and they die in the snow.  Usually a cleansing flight.

I also have the bottom board full of dead bees at the end of winter, due to the bees dying on the outside of the cluster.

Cheers,

ApisM
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Offline ApisM

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Re: Population losses. Reposted to correct forum.
« Reply #1 on: January 19, 2014, 11:06:12 am »
It is often a topic that is not in print, but gained through practical experience.  As mentioned, everyone talks about losses in regards to perished colonies.  It would be interesting to see a study of successfully overwintered colonies and what population loss they experienced.

I have no mites yet.  I live in one of the last areas unaffected by mites in North America, so I believe.  I do wrestle with Nosema each winter, but trying to breed survivor colonies.  I do not use chemicals, trying to develop a hardy stock.......it keeps my colonies numbers down while improving the genetics.  I am only a hobbyist.   
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Offline Bush_84

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Re: Population losses. Reposted to correct forum.
« Reply #2 on: January 19, 2014, 12:07:21 pm »
Well I can't tell you the quantity of bees that a hive may lose in the winter but I think what you are describing is normal, but in am not sure they are dying from what you think they are dying from.  I'm a fairly new hobby keeper as well.  So take what I say with a grain of salt.  But I don't believe bees fly out when they know it's to cold to fly.  I believe that the bees you see on the outside were either carried out or came out to die.  Also the bees on the floor has been the norm of every hive that I have seen.  Bees die in winter.  It is what it is.

There is one thing I also contend with and that's the common saying that cold doesn't kill bees wet does.  I wholeheartedly disagree with that.  Yes some things are certainly worse on bees such as wet and cold bees, but I won't accept the fact that cold doesn't affect bees.  I think it does increase the winter kill off of individual bees.  I think that is causes starvation in more than one way.  I think it also causes a slow and steady decline in large and small hives.  I also know that it kills hives that would have over wintered in a milder climate.  So IMO those who say that cold doesn't kill bees live in a climate that is much milder than ours. Anyways....done ranting.  :)
Keeping bees since 2011.

Also please excuse the typos.  My iPad autocorrect can be brutal.

Offline ApisM

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Re: Population losses. Reposted to correct forum.
« Reply #3 on: January 19, 2014, 01:38:56 pm »
Thanks for the rant.

The bees were not carried out.  I watch them fly out themselves and get hit by the cold temps and plummet to their death in the snow.  The sun warms the hive inside and they become more active, but the temps are still cold in the air.  So they attempt to do a cleansing flight and die, or maybe they are sick, as you say.

Not sure what to do, but maybe they won't last this year.  I'll keep you posted.

So question.  If you have 30,000 bees in a hive, what is your average population loss of a survivor colony?
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Offline Bush_84

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Re: Population losses. Reposted to correct forum.
« Reply #4 on: January 19, 2014, 02:12:53 pm »
The strength of a colony in spring doesn't always correlate with the strength in the fall in my limited experience, but obviously a strong hive in the fall will do the best.  I have been surprised to see a weaker hive come out strong in the spring and strong hives perish in winter.  I will tell you that it's normal to see a large wad of dead bees on the bottom board. 

I guess the question really is how many frames of bees do you have alive in the hive?  Do they have ample stores? 
Keeping bees since 2011.

Also please excuse the typos.  My iPad autocorrect can be brutal.

Offline ApisM

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Re: Population losses. Reposted to correct forum.
« Reply #5 on: January 19, 2014, 07:38:40 pm »
Hello Bush 84,

That is an interesting comment about the strength in the Fall doesn't necessary equate to survival.  I once got a nuc to overwinter up here, while other full strength colonies perished.  I used a terrarium heater for two hours a day (in the night when the temps were in the -30's), and this seemed to allow the nuc to survive.

In my question 30,000 bees might be 12 frames of bees?  basically a full strength colony...two full hive bodies full.  So what is the average expectation of population survival (10,000, 20,000,.....?)  I guess many factors, but I would imagine that a 40% cull rate is probably the average, right?  This is what I am understanding from you.

Cheers.
It is easier to catch flies with honey than with vinegar

Offline Bush_84

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Re: Population losses. Reposted to correct forum.
« Reply #6 on: January 19, 2014, 08:18:18 pm »
Pretty sure I don't know the answer to your question...the other thing to keep in mind is that in some bee breeds and in some locations there may only be a short time of no brood.  So if the bees start brooding up in January, how do you determine what percentage of fall bees die when the bees you count in the spring may not all be the same bees in the fall?  Either way I'm not sure I have an answer for you. 
Keeping bees since 2011.

Also please excuse the typos.  My iPad autocorrect can be brutal.

Offline ApisM

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Re: Population losses. Reposted to correct forum.
« Reply #7 on: January 19, 2014, 08:59:38 pm »
Hi Bush,

My queen is done with all brood rearing by November.  there are no capped brood at this time.  She then starts laying in April.  So during the main part of the winter, there is no brood to replace any lost bees.  So I don't have a unique breed.

My cluster moves around from frame to frame during the winter, feeding on the stores, so no time or ability to rear anything at this time in the extreme cold.

I appreciate your comments, I guess nobody else has anything to contribute in this forum.  It would be nice to hear what other people are encountering with survival colonies and their losses.

Apis.
It is easier to catch flies with honey than with vinegar

Offline Bush_84

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Re: Population losses. Reposted to correct forum.
« Reply #8 on: January 19, 2014, 09:46:00 pm »
How can you be so sure there is no brood?  I would have thought the same except I just dissected a dead out, which revealed a patch of brood 4-5 inches in diameter on each side of a single frame.  Our winters in Minnesota are also fairly nasty and it has been a cold one this year.  Food for thought.
Keeping bees since 2011.

Also please excuse the typos.  My iPad autocorrect can be brutal.

Offline ApisM

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Re: Population losses. Reposted to correct forum.
« Reply #9 on: January 19, 2014, 11:09:15 pm »
Now that is interesting. 

I have previous experience with dead-outs and never saw capped brood.  Just uneaten honey.  I related the dead-out with cold starvation; bees unable to move to the next frame to get the honey because it was too cold.  Your observation now has me rethinking some things that I was not aware of previously.  It has been great chatting with you Bush_84
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Offline edward

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Re: Population losses. Reposted to correct forum.
« Reply #10 on: January 19, 2014, 11:34:09 pm »
Cold Winters doesn't kill strong hives.

Cold will kill weak hive that don't have a critical mass of bees able to keep warm.

In Cold Winters hives that have brood consume stores and wear down the hive, eating more food fills the bowls, make the bees need to poop. The also have to generate a lot of extra energy to keep the brood warm.

- 10oC is the best temp for bees to ball together and keep warm using a minimal amount of stores.

Bees fly out of the hive through out the Winter, better to die outside away from the hive.

40000 - 60000 bees is a strong hive.

You also have to go into the Winter with the right kind of bees, Young bees that hatched in late summer and early fall.
If the hive is only old worked out worker bees it will not survive well.

The bee mass can dip in the early spring when old bees die and not enough new bees have hatched yet, there numbers can reach 12000, under this period the beekeeper should restrict ventelation to help them keep the brood nest warm.


mvh Edward  :-P

Offline Bush_84

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Re: Population losses. Reposted to correct forum.
« Reply #11 on: January 20, 2014, 12:19:09 pm »
Cold may not kill a strong hive overnight but it will certainly wear them down.  It is also possible for a strong hive to die in a long cold snap in which they have a tight cluster and are unable to move to a new location.  Next winter I am going to see what i can do about wintering in a shed, but that's for another topic.  :)
Keeping bees since 2011.

Also please excuse the typos.  My iPad autocorrect can be brutal.

Offline edward

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Re: Population losses. Reposted to correct forum.
« Reply #12 on: January 20, 2014, 04:17:28 pm »
If they have food and can reach it and they are strong, then it is not a problem. My Winters are from November to April with temperatures - 8 oC to - 20oC as normal with dips to -30oC 35oC. With out problems.

One of the bigest problems is dampness and condensation in the hives. Also if the temperature variations are large the hive has to work harder to regulate the temperature and use more stores.

mvh Edward  :-P

Offline ApisM

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Re: Population losses. Reposted to correct forum.
« Reply #13 on: January 21, 2014, 12:19:37 am »
Thanks Edward for you comments as well.  I guess what I experience is somewhat normal.  However, it is a topic that is not discussed.  In warmer climates, how do the bees fair in the winter?  does the bottom board fill up with dead bees too.  I have colonies that are 40K strong and come out of winter with only 10k left.  Does this happen in southern climates?

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Offline edward

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Re: Population losses. Reposted to correct forum.
« Reply #14 on: January 21, 2014, 12:38:40 am »
Our Winters may bee cold, but even in warmer climates they have a winter.

No pollen and no nectar coming into the hive and the bees are still flying  :-x

I Think I prefer our cold winter. Kind of like Peace and quiet when the kids go to bed insted of running around.

The warmer Winter they have to feed the bees all the time.


mvh Edward  :-P

Offline Joe D

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Re: Population losses. Reposted to correct forum.
« Reply #15 on: January 21, 2014, 02:19:37 am »
Down here I don't have a big build up of dead bees on the bottom boards.  Usually there are a few days at least per week where they clean the bottom boards and fly around.  I try to leave enough honey so I don't have to feed.  This past year and this winter have been worst for my bees.  Late freezes and rain in the spring, this winter it is in the teens then in the sixties, up and down.  I have been in my hives since late fall, some still are heavy some not so much.  I have feed a little under one gal of sugar syrup per hive in the last week.  Today they were flying everywhere, temp got up to 68F.  Thursday the high is supposed to be in the low 30's.  You have the loss of the drones in the fall, the loss of some workers as the winter goes on and hopefully in the spring you still have a good size hive.  Good luck to you all.


Joe