[nguiver]

Somewhere between 20 and 5 million years ago.

"Distribution rights" ... for a hole in a box ? I'm clearly in the wrong job.
LJ

I think there is a little more to it than the hole .. hey ho .. we will see.

 

[gnor]

Hi
So what are the benefits of a bottom entrance considering the fact I have to go to the apiary every night and close it up and then back every morning to open it up again, otherwise i am chilling the brood.

Seely found that bees in trees preferred a bottom entrance about 2 square inches. Gravity helps them clear dead bees, wax cappings, and so on.
They have avoided chilling the brood for hundreds of millennia, so they are pretty good at it.
In Summer, my entrance is 13/16 x 14-1/2 (11.75 sq in). I add a reducer in Fall when I see less bees flying or I see a lot of robbing. Other than that, I let the bees manage things inside the hive.

 

[GregV]

Seely found that bees in trees preferred a bottom entrance about 2 square inches. .......

According to his latest book - this has been revised.
I have exact page to show if asked.
This is not widely advertised either (just kinda in passing).


He now got better at finding the wild bee nests high above the ground.
Turned out - his earliest numbers were biased towards the low-placed nests with bottom entrances.
Back then he could not find the nests high above too well (now days he find them well, no matter how high - by bee-lining).

 

[nguiver]

Seely found that bees in trees preferred a bottom entrance about 2 square inches. Gravity helps them clear dead bees, wax cappings, and so on.
They have avoided chilling the brood for hundreds of millennia, so they are pretty good at it.
In Summer, my entrance is 13/16 x 14-1/2 (11.75 sq in). I add a reducer in Fall when I see less bees flying or I see a lot of robbing. Other than that, I let the bees manage things inside the hive.

Hi Thanks for that .. I suppose that up in trees there is less problems with rodents, and as far as detritus in concerned how do they clear it in feral colonies where the entrances may be anywhere? perhaps "help" is a human preconception. Deep litter in live stock is seen as muck to be cleaned out by some and a heat source by others. So as far as chilling brood is concerned is there any evidence of large bottom entrances in feral colonies? and in managed hives perhaps we should give them a box full of holes and let them decide what they want, propolise the rest and not impose something on them that they keep having to adapt to, every time we decide to change it.

What a facinating animal to study ... the human.

 

[crofter]

I am surprised thet Little John has not taken you to task yet. His colonies survive very well with a wide open hive bottom. It would be fatal though in winter if used with the large upper ventilation that works in other systems.

Very small lower entrance with no upper ventilation is also fatal if some circumstance plugs that small bottom entrance. Ask me how I know about that.

We have to be careful with the vision we get peering through a knothole.

 

[nguiver]

I am surprised thet Little John has not taken you to task yet. His colonies survive very well with a wide open hive bottom. It would be fatal though in winter if used with the large upper ventilation that works in other systems.

Very small lower entrance with no upper ventilation is also fatal if some circumstance plugs that small bottom entrance. Ask me how I know about that.

We have to be careful with the vision we get peering through a knothole.

Hi Frank

i have 3 groups total 47 colonies in 5 acreas. One in amongst the trees, one facing south full aspect sun trap and one east part in the trees. I think we all agree that every location is unique and has its own way of surviving, or not. Pesticides are our main issue which we are addressing.

 

[crofter]

Local conditions. For certain... I have no wax moths or small hive beetles and the Carni style bee I have shows close to zero inclination to swarm. We can get up to 3 feet accumulations of snow and approaching -40 F is not uncommon. I effectively lost most of my colonies last winter from apparent being suffocated by heavy snow and an unusual heavy rain with a quick return to freezing. I had only lower entrances which was a new thing to try. The warm trapped bubble at the top was a convincing image! I bought in.
The previous 6 winters with 6 or 8 hives I had zero winter losses. The autopsies did not point to any of the other typical winter loss causes.

This winter they have a 1" hole below the handle in the top brood box and a half by three quarter hole in the feed shim. Most of the colonies have partially propolized the feed shim holes to one or two bees width. Bottom entrance with mouse guard is roughly 3/8 by 3 inches.

 

[little_john]

I am surprised thet Little John has not taken you to task yet. His colonies survive very well with a wide open hive bottom.

LOL ...

I've actually been more focused on this claim of bees preferring to live in cavities with a bottom entrance. I'd suggest that early hive designers simply copied this particular feature, and many of us have stayed with it - essentially because it works. If it didn't work, then I'd be the first to change to something better.

But preferring implies that the bees had made a choice, and one can only talk in terms of a choice having been made if some nearby cavities with different entrance positions had also been identified, with bees having refused to live in them - which of course Seeley wasn't able to do - or anyone else, afaik.

Far more likely, imo, is that tree cavities represent rare and valuable real estate in the Natural World, especially as other creatures also value them - and so in practice bees occupy whatever cavities they can find.

But how come so many cavities have entrances near their bottom ? The answer is deceptively simple. Cavities are formed by the rotting of heart wood following traumatic damage to the tree bark. This can occur either near the tree's base (from forest fires or deer), or higher up from limbs having been snapped-off by neighbouring trees falling and striking them as they crash to the ground.

With damage near ground level, rising damp from the earth causes the heartwood to rot, and with limb damage at height the remnants of the limb act as an efficient rain-catcher, initially causing rot of that limb, with this rot then continuing into the trunk itself. Following damage at ground level, it's obvious that the entrance will be at the bottom of the cavity which then forms, but with limb damage the entrance position which develops is slightly less obvious.

The organisms (bacteria, fungi etc) which cause rotting of wood thrive in a damp environment, but not one which is soaking wet. This can readily be seen when wooden fence posts are driven into wet ground - where the maximum rate of rotting will always be observed close to the soil's surface - for these are aerobic organisms (i.e. they require oxygen to live). Hence back in our developing tree cavity, maximum rot will be occurring at it's upper surface, and far less down at it's bottom - so that the original point of entry appears to move downwards as the cavity itself develops in an upward direction.

This tree cavity formation mechanism is described on many arborist's sites - I didn't make this stuff up - honestly !

Another point I'd like to mention is that the diagram on Seeley's paper which shows a single relatively small entrance ... was only ever meant to be representative of what he found - it was never meant to be a blueprint upon which to base hive designs. Tree cavities result from random traumatic damage and each one will be unique - these cavities are 'Natural' in the sense that they occur in Nature, but are totally 'un-Natural' in the sense that very few trees will ever develop such cavities.

Finally, a rather sobering description (perhaps ?) of a tree cavity by ROB Manley:

Of course it is far better not to keep bees in places that are not exactly right, but needs must when the devil drives, and bee farmers find themselves driven that way more often than is exactly convenient. So if you have bees so situated, take a lot of bits of wood one-eighth of an inch thick, or less, section wood will do, or matchsticks, or even some two-inch wire nails, place one of these small objects under each corner of the inner cover, and your hives will usually keep dry enough. This question of dissipation of the moisture thrown off by the bees is a very important one; much more so, I believe, than packing and double-walled hives, for in my opinion bees do not need to be insulated, packed or ****ered up in any way in Britain. After all, they winter perfectly well in chimneys, roofs, and all sorts of cold, draughty places. I remember one lot in an old pollard willow when I was beginning to take an interest in bees. The combs were all of four feet long, the tree was split from top to bottom, and the combs could be seen in half a dozen places. It had been there for many years, the farm men said, and might have been there much longer had I not come along.
Again, I saw some of Madoc's hives in Norfolk one winter, when woodpeckers had made large holes. In some cases the holes were big enough to put your fist into, and the clustered bees could be seen through them, but the bees wintered all right, I believe. I have seen bees come through the winter well when housed in old cracked boxes that were about as airtight as a colander ...

And - for the benefit of 'Top Entrance' beekeepers ...

Maybe I ought to say a word about top entrances for wintering. The trouble is that I have never tried them. I'm always intending to; but when the time comes we are all so dreadfully busy that it gets put off until next year. All I can say is that it seems well established that bees winter well with these entrances arranged at the top of the hive, combs do not get mouldy and hives keep dry and sweet. I must try some - next year. The difficulty seems to me to lie in the changing over, at the time of putting bees into winter shape, from the bottom to the top entrance, and in the reversing back again in the spring ...
ROB Manley, 'Honey Farming', 1945.

LJ

 

[Juhani Lunden]

Local conditions. For certain... I have no wax moths or small hive beetles and the Carni style bee I have shows close to zero inclination to swarm. We can get up to 3 feet accumulations of snow and approaching -40 F is not uncommon. I effectively lost most of my colonies last winter from apparent being suffocated by heavy snow and an unusual heavy rain with a quick return to freezing. I had only lower entrances which was a new thing to try. The warm trapped bubble at the top was a convincing image! I bought in.
The previous 6 winters with 6 or 8 hives I had zero winter losses. The autopsies did not point to any of the other typical winter loss causes.

This winter they have a 1" hole below the handle in the top brood box and a half by three quarter hole in the feed shim. Most of the colonies have partially propolized the feed shim holes to one or two bees width. Bottom entrance with mouse guard is roughly 3/8 by 3 inches.

In heavy winter conditions it works well to have wide bottom entrance or whole bottom open. The most deadly set-up is one smallish bottom entrance.

I have entrances both ways in winter (=entrance is double size in winter compared to summer) and my bees have consumption just like in this article. https://www.beeculture.com/winter-management/

Abundance of bottom ventilation does not make bees consume more than nearly optimum.

"E.B. Wedmore calculated the amount of honey required to overwinter a measured population of bees in his influential 1947 book, The Ventilation of Bee-Hives. Wedmore converted the caloric content of honey to watts and then using wattage he calculated that the basic needs are about three lbs. per month between mid-October and mid-April. Therefore, if Wedmore is correct, and the primary Winter honey requirements of an average population of bees are in the range of ~21 lbs., it seems like our need to provision Winter stores at four times that amount, may indicate something about the burden on bees to generate additional heat beyond their basic needs. One obvious reason is the loss of heat by an abundance of added ventilation.
For many decades, beekeepers have devised ways to use the inner cover’s conveniently placed Porter bee escape hole to ventilate all that warm moist air, without regard for the consequences of lost heat.
The next question is how much of our current practice of provisioning 60-100 lbs of honey per wintering colony, then providing supplemental fondant, and in some cases ending with the need for emergency food, is being driven by removing lots of heat the bees must replace?
There’s no question that ventilation is needed, but I think if we could refine our understanding of how much is needed and when, modify our boxes to direct the convective flows away from the cluster’s center, and increase insulation around the Winter cluster, we could help our bees live healthier, lessen the burden of Winter provisioning, and reduce Winter losses."

 

[little_john]

"There’s no question that ventilation is needed, but I think if we could refine our understanding of how much is needed and when, modify our boxes to direct the convective flows away from the cluster’s center, and increase insulation around the Winter cluster, we could help our bees live healthier, lessen the burden of Winter provisioning, and reduce Winter losses."

There's another issue which keeps occurring to me, although it would need a lot more thinking about before any trials were undertaken ...

... and that is the whole issue of ventilating to eliminate moisture. Who says that bees need to live in a nice warm dry snug cavity ? For many millions of years bees have survived by living in tree cavities, which are formed by the rotting of wood, which only ever takes place when that wood is kept moist - either from rainfall, or from rising damp. The bees then carve away that rotten wood, smear the remaining surface with propolis, and begin drawing their wax combs onto wood which is now largely protected from further rotting.

So why has evolution chosen these two materials: wax and propolis, both of which are water repellant, rather than (say) the paper nests which wasps employ ? Could it just be that evolution has 'chosen' these in order to survive within a very damp environment ? There is of course the additional requirement of effective food storage which the wasp doesn't have, so it can't be that simple - but I do sometimes wonder if we humans aren't projecting our own environmental requirements onto those of other creatures.
LJ

 

[Robert Holcombe]

I have read and saw a pic showing a PVC pipe vent from the bottom of the hive up to provide a vent to the void that normally forms under the snow. I would guess it was a CO2 issue as it is heavier than air. I have no idea how much diffusion would occur via the pipe, how CO2 saturates the snow - assume bigger diameter pipe the better. I rarely have that kind of issue of any magnitude. It happens often here but with much smaller amounts of snow. I run a no-top-vent, insulated hive configuration and a screened bottom vent + reduced exit with good results. I call it the "living bubble" controlled by the bees.

 

[GregV]

........ [/B]Therefore, if Wedmore is correct, and the primary Winter honey requirements of an average population of bees are in the range of ~21 lbs., it seems like our need to provision Winter stores at four times that amount, may indicate something about the burden on bees to generate additional heat beyond their basic needs. One obvious reason is the loss of heat by an abundance of added ventilation.........

At least in the US (with the abundance of the commercial Italian bee lineage mixed in, and oversized Langstroth equipment used) - wintering exclusively large clusters is both a problem and a necessity (try wintering in 3 deep/10-frame Lang tower).
Here is a rough attempt to show the problem numerically:
https://www.beesource.com/forums/sh...-wintering-cluster-size&p=1764593#post1764593

People around me routinely advice to have 100-120-140 lbs of stores to winter.
They try to winter huge clusters for no obvious benefit.
Just how they are told to do by the experts.

I contend my strongest bees winter fine on about 50 lbs of honey.
Reduced to about 8 jumbo frames (similar to 10-frame Lang; single box for everything - bees and food).
No more is needed for successful wintering - not frames, not honey, not bees.
More of these things are needed in spring and summer, not in winter.

 

[Fusion_power]

I live in a very humid climate so can answer LJ's speculation about moisture. It will absolutely kill a colony of bees if too much builds up inside the hive. I tried to keep bees with just a small bottom entrance (3 inches by 3/8 inch high) when I started keeping bees 50 years ago. The result was abject failure with loads of nosema, mold covering the combs and woodenware, and bees that either were very weak or already dead by the time I realized something was wrong.

Here in the Southeastern U.S. the most critical winter requirement is to have enough ventilation to prevent excess moisture buildup in the hive. It does not take much. Just a tiny crack near the top of the hive will let most of the moisture out without too much heat escaping. No, I don't use matchsticks. For years, I used a notch cut into the hive cover that was 3/4 inch wide by 3/8 inch high. For small weak colonies or nucs, I close the notch with a small block of wood. They don't need the ventilation. Strong colonies do.

 

[Robert Holcombe]

Ventilation or moisture controll is a difficult issue to discuss. Dereck Mitchell has done a nice job of critiquing E.B. Wedmore's conclusions which are based on one thermometer reading that a hive needs a top ventilation hole. He repeated the experiment with multiple thermocouples. I have not read Wedmore's minimum consumption calculation but I find nearly all related literature about metabolic consumption descriptions deficient in explaining heat transfer boundary conditions (which should include fluid dynamics) when collecting or publishing data. I have worked hard on trying understanding this internal environmental issue. I have also conducted testing using very crude but seemingly effective sensors on a number of hives for two winters. I find a 5-sided insulated (R10) hive with no top vent supports bee activity in winter quite well ( I am in a humid coastal location that also goes below 0 F occasionally, single digits often. I see data showing bees regulating hive top bubble temperatures from 50 - 60 F but raising it in high humidity, cold rainy weather significantly. Given a hive design which supports their heat generating ability( equaling or exceeding heat loss) , they seem to be able to control the upper internal surfaces above the dew point. I seem, with crude sensing especially humidity sensors, to have measured controlled temperature - RH regulation over time. I am repeating my efforts this winter now that I have some clues. I believe the bottom of the hive provides a vapor diffusion zone ( screened bottom board and entrance) and a cold condenser, hives sides and possibly empty cells(?) This likely is providing recyclable water (a big plus?). This dta is mostly weakly supported data but provides a hypothesis based on conservation of energy principles, thermodynamics of the water cycle and specifically focused on heat & mass transfer both by the bees and the hive design. I may be smart enough now to design a viable experiment to prove the point(s). The test problem is being able to sense multiple temperature and humidity data at multiple locations within a hive(s) in a short time frame at reasonable cost for a backyard beekeeper.

 

[Robert Holcombe]

Congratulations on the "treatment free" hives! I'm 50 years into applied engineering going into 5th years of beekeeping. I raise my own bees and some queens but have to treat in the Fall winter.

The "mold" in the hive observation clearly indicate condensed free water. The walls or hardware in the hive were getting too cold, causing condensation. It could be a resultant of weak bees or inability of a large cluster to match heat loss all the time. If the surfaces do not fall below the dew point base on internal hive's surfaces you will not have condensation.

You should see the water collect between my covered boat's inner and outer hulls all winter. I have to leave an open drain plug and raise the bow. There are no bees or honey in there

 

[little_john]

I live in a very humid climate so can answer LJ's speculation about moisture. It will absolutely kill a colony of bees if too much builds up inside the hive.

And yet we observe the bees' gluing-up of cracks within a beehive (which would otherwise provide some ventilation) - with their priority always being to seal the topmost area first. And - they can often be observed to have reduced the size of an entrance too. It would appear that their behaviour is directed towards sealing-up their cavity as tight as possible, leaving just the smallest of entrances - i.e. zero passive ventilation.

Yet the amount of water produced by dessication of nectar into honey, and the amount produced as a by-product of honey/sugar metabolism during winter is phenomenal.

How do we square these two observations ? Are we to accept that bees have some kind of inherent 'death-wish' and are hell-bent on suicide - or is there another explanation we're overlooking ?
LJ

 

[GregV]

Yet the amount of water produced by dessication of nectar into honey, and the amount produced as a by-product of honey/sugar metabolism during winter is phenomenal.

How do we square these two observations ? Are we to accept that bees have some kind of inherent 'death-wish' and are hell-bent on suicide - or is there another explanation we're overlooking ?
LJ

At least in the temperate forest setting, here is a typical wild bee dwelling.
Both observations coexisted beautifully for very long time.
Bees, unfortunate to settle in sub-standard homes simply got terminated (today bees placed in sub-standard homes get propped up by various tweaks).

 

[Fusion_power]

How do we square these two observations ?

Ask the bees. They have never lied to me.

 

[crofter]

Congratulations on the "treatment free" hives! I'm 50 years into applied engineering going into 5th years of beekeeping. I raise my own bees and some queens but have to treat in the Fall winter.

Robert what is your thoughts regarding possibility that an overabundance of insulation would result in the bees being too warm and therefore not entering the low metabolic state and thus consuming more stores. Other words is there an optimum amount of insulation.

Three colonies I have wrapped have propolized the 1/2 sq. in. hole in the feed rim area down to a hole barely bee diameter. They have also started to reduce the 1" diameter hole at the handle of the upper brood box. I have used some 4" foamboard because it was free, not that I thought that thick was necessary. The upper box is shavings filled and vented.

 

[little_john]

I live in a very humid climate ...

My location is 'damp' - i.e. 'humid', but without the heat. This is a turning area alongside my driveway:



So I kill off the moss every 3 or 4 years, but it just keeps coming back. The water table can be as high as 12-18" below ground in Winter - only then then do they turn the drainage pumps on.
We've had a lot of rain recently and many fields are flooded - the drainage ***** (ditches) are nearly full, and so I'm expecting pumping to start any day now. Good conditions for ducks, geese, frogs ...
LJ