Two new papers on honey bees

[Repwoc]

In summer, do you have any hive ventilation other than the entrance?

 

[TooBee...]

...Did you see any water running out of the hive?

That's a very good point actually!

(I'll try and pay more attention to my maths this time )

7 Litres of water per day (we'll use Finmans max. example) is 291.66ml per hour, which is 4.861ml per minute, there are about 20 drops per ml (I think) which is 97.2 drops per minute, which is 1.6 drops per second or put another way every 2/3 second a drop would have to drop from the hive entrance / floor, etc. to drain out 7L of water (assuming a constant rate, which it will not be, I think most curing occurs at night), does make one think, I see you too are thinking about the same things I'm pondering, whereabouts does all that water go, which then begs the question how do they get rid of it that's a lot of work to have that many air changes ... makes me think about Clark's Condensation Hive again.

In summer, do you have any hive ventilation other than the entrance?

No... not even an Open Mesh Floor, like all the old time beeks.

 

[Repwoc]

If there was any water lying on the floor it would push the humidity to almost 100%, which would bring nectar desiccation rate down to near zero.

I'm thinking the water must leave the hive as vapour by advection through the entrance (in the absence of alternative ventilation) which suggests that large volumes of air must be exchanged. If the external temperature is 35 C as Finman said then the bees don't need to warm it up by much.

Finman - how high is the relative humidity in your summer when the temperature is 35 C?

 

[Beefriendly]

Maybe all you theorists should learn how the bees do it.....

 

[user 6228]

If there was any water lying on the floor it would push the humidity to almost 100%, which would bring nectar desiccation rate down to near zero.

I'm thinking the water must leave the hive as vapour by advection through the entrance (in the absence of alternative ventilation)

if the temperatture near the nectar is higher than near the floor then you have a difference in humidity.

And all that yellow rain contains water so it doesnt all leave in the vapour phase

 

[Finman]

If there was any water lying on the floor it would push the humidity to almost 100%, which would bring nectar desiccation rate down to near zero.

I'm thinking the water must leave the hive as vapour by advection through the entrance (in the absence of alternative ventilation) which suggests that large volumes of air must be exchanged. If the external temperature is 35 C as Finman said then the bees don't need to warm it up by much.

Finman - how high is the relative humidity in your summer when the temperature is 35 C?

I meant temp inside the hive.

There is no permanent relative humidity in Finland.

Water laying in floor in summer!!!... Pure imagination.
After rain it is possible if floor continues as landing board.

Your calculations are really mad, I must say.
You cannot help hives with those calculations.
.

 

[Finman]

In summer, do you have any hive ventilation other than the entrance?

I have main entrance wide open in June, and there are 2-3 upper entrance open in 6 box hive. Upper entrances are 15 mm diameter.

Lowest brood box becomes cool and bees store mostly pollen there.

 

[Repwoc]

if the temperatture near the nectar is higher than near the floor then you have a difference in humidity.

Probably.

And all that yellow rain contains water so it doesnt all leave in the vapour phase

Are you suggesting that they drink it all?

Obviously the bees consume nectar to enable them to generate heat and waft the air about in the hive. That will produce yellow rain.

 

[Repwoc]

I meant temp inside the hive.
Your calculations are really mad, I must say.
.

Why are they mad? The basic calculation of how much water must be evaporated from the nectar to make honey is pretty straight forward.

 

[user 6228]

Probably.



Are you suggesting that they drink it all?

Obviously the bees consume nectar to enable them to generate heat and waft the air about in the hive. That will produce yellow rain.

They may be... research is noticeably absent about the collection of condensate and the excretory behaviour of A.m.
I have seen bees drinking condensate. ~I have seen them excrete a liquid. So it isnt impossible
That all I can reliably say,

 

[Finman]

Why are they mad? The basic calculation of how much water must be evaporated from the nectar to make honey is pretty straight forward.

But bees have done it millions of years without human help, and they continue to do it. But now this forum will reviele it out without any research.

Derekm has seen that bees drink condensation water.... During heavy nectar flow... And yellow rain contains water...

 

[Repwoc]

But bees have done it millions of years without human help, and they continue to do it. But now this forum will reviele it out without any research.

Derekm has seen that bees drink condensation water.... During heavy nectar flow... And yellow rain contains water...

That doesn't make the calculations mad. Most theories are based on observation and hypothesis followed by experiment and/or data gathering leading to proof. The above discussion is just hypothesis based on what we know (nectar contains water that is evaporated to increase the sugar concentration) and other observations (no one has seen water dripping from hives and bees make yellow rain) together with some conjecture, assumptions and calculations (eg if the water is removed by advection, how much air would need to be exchanged).

If we can determine how the bees remove all the excess water from the hive and we can help them to do it more efficiently, then that may improve honey yields. Would that be mad?

 

[Repwoc]

They may be... research is noticeably absent about the collection of condensate and the excretory behaviour of A.m.
I have seen bees drinking condensate. ~I have seen them excrete a liquid. So it isnt impossible
That all I can reliably say,

We know that bees do forage for and transport water into the hive. Presumably they could carry it out by the same means, rather than drinking it. That would require a lot of bee activity (leaving the hive to remove water and then returning) during honey ripening which apparently happens mostly at night.

 

[TooBee...]

Derek's right about this, there's very little research, and we're now having to guess at what happens...

We do know that water does not drip out from the entrance ... but the number of total volume air changes in the hive seem extremely excessive?

Water could collect on the bottom floor, maybe not necessarily in a puddle, the floor temp. presumably would be warmer (certainly at night) than outside, in a natural tree cavity the floor is below the entrance, which we know from research increases the natural passive air flow between the inside and outside of the hive floor area. If there is a temp. differential (which I think we can agree that there is - even with an Open Mesh Floor) then there would be an exchange of air ... could this be one way in which the high internal humid air is exchanged for less humid external air.

IF you have a room in which the temp. is the same throughout, and there is little or nothing to cause air movement in the room, and then IF the air at one side is made (somehow) more humid, how does this affect the movement of air within the room, does the humidity equalize within the room, or is the (presumed) Phase Change (???) that occurs cause a temp. differential, which in turn will cause air flow within the room and it is the temp. that equalizes and not the humidity - I'm not sure what this would be called, and I haven't been able to find a clear answer online.

 

[Repwoc]

Derek's right about this, there's very little research, and we're now having to guess at what happens...

That's how it is with any research; hypothesis (educated guessing) followed by experiment/observation to determine its validity.

We do know that water does not drip out from the entrance ... but the number of total volume air changes in the hive seem extremely excessive?

If the water doesn't dribble out as liquid, and the bees don't carry it out (which they may well do) then the only other mechanism I can think of is advection, ie by exchange of air to the outside. I used the on-line data to calculate the volume of air needed to remove a gram of water, with some assumptions regarding internal and external temperature and RH (which may or may not be valid).

IF you have a room in which the temp. is the same throughout, and there is little or nothing to cause air movement in the room, and then IF the air at one side is made (somehow) more humid, how does this affect the movement of air within the room, does the humidity equalize within the room, or is the (presumed) Phase Change (???) that occurs cause a temp. differential, which in turn will cause air flow within the room and it is the temp. that equalizes and not the humidity - I'm not sure what this would be called, and I haven't been able to find a clear answer online.

If you have a concentration gradient of something - in this case water in air - then the something will diffuse from the region of high concentration to the region of low concentration. See Fick's laws of diffusion: https://en.wikipedia.org/wiki/Fick's_laws_of_diffusion

 

[Gilberdyke John]

We know that bees do forage for and transport water into the hive. Presumably they could carry it out by the same means, rather than drinking it. That would require a lot of bee activity (leaving the hive to remove water and then returning) during honey ripening which apparently happens mostly at night.

On a sample of one, my first give was a WBC with a solid floor. During the autumn of my first year the landing board was wet in the mornings with streaking of water coming out of the hive.
Going to OMF the phenomenon disappeared.

 

[charlievictorbravo]

That doesn't make the calculations mad.....

If we can determine how the bees remove all the excess water from the hive and we can help them to do it more efficiently, then that may improve honey yields. Would that be mad?

We should not underestimate the importance of understanding how bees remove moisture from the hive. Tom Seeley suggests that, in a natural tree hollow nest, the bees favour a single entrance with a fairly small area - 40 mm square if memory serves. Nobody, as far as I have seen, knows exactly how that small hole into the bee enclosure copes with in and out traffic plus moisture removal. Even discounting the in and out traffic of foragers, how does moist air exit and ambient air enter through such a small hole?

If sensible people don't use science and observation to work it out, the matchstick men will win the day!

CVB