Hi
Long post.
First some bee biology.
Bees have evolved over many millions of years to build their comb (the fixed
part of the superorganism) in cavities. For many reasons (eg heat rises) comb
is built from the top of the cavity downwards. The top of natural cavities is
fixed; it does not move. Hence, in natural conditions, no bee has ever come
across a situation where space suddenly appears above the top of the combs.
One could reasonable expect that, were this to happen, the bees might well get
more than a little freaked out. Yet this is exactly what beekeepers do as a
matter of course. Firstly, it’s easier to put boxes on the top of a pile
rather than at the bottom. Secondly, the reaction of the bees is to fill that
space as quickly as possible, by building comb and filling it with brood,
honey, pollen etc. In other words, the bees seek to recreate the nest
arrangement that was there before the space appeared. BUT beekeepers want
honey, so they place a physical barrier in the way which prevents the nurse
bees accompanying the queen up to the new space. Hence the bees respond to the
"empty attic" by filling it with honey. The beekeeper thinks this is
wonderful, little realising that this is a stress response.
Dear old Abbé Warré realised at least some of this when he developed hives in
the late 1800’s and early 1900’s. Hence the concept of nadiring, or adding
boxes below rather than above. One might reasonably assume that bees would be
less sensitive to new space suddenly appearing below the colony than they would
be to space appearing above. This may be so, or it may not. But that is
perhaps for another day.
With all this in mind, and after conversations with Torben Schiffer the German
researcher (who coined the phrase "empty attic"), I have been experimenting for
a couple of seasons to see if I can answer the following question: is there any
volume one can add to the top of the hive that does not cause the bees to
respond by thinking the attic is empty and entering into the stress response of
reconfiguring the internal arrangement of the colony?
Ideally, the bees would leave the brood nest exactly as it is and just store
honey in the newly added super when the main body of the hive is full. I have
been working with Golden Hives, not Warrés, but the principles seem pretty clear
I have used two variants of hive, one which holds 12 combs and one which holds
8 combs. The 8 comb variant has exactly the same cross section as a Warré,
whereas the cross section of the 12 comb hive is like a Warré with an
additional half box on the side. The depth of the main hive in both variants
is 485mm. The volume of the 12 comb hive body is roughly equal to 3 ½ Warré
boxes. The 8 comb variant comes in at roughly 2 ⅓ Warré boxes. I say
"roughly" not because I can’t do the sums but because I see no point in getting
into considerations of whether one measures the volume externally or internally
to the frames. For me, that falls under the label "false exactitude".
Just before the start of the main honey flow (ie about the first week in June)
I added a super to several of each hive variant. The super is 100mm deep. On
the small variant, this is a volume of half a Warré box. On the large variant
the super has a volume of about 3/4 of a Warré box. I am thus adding about
1/5th to both the volume and height of the hives. Both supers have frames in
them which have bottom bars but no foundation. Comb guides are minimal and of
the line of wax type. These are on both the top and bottom of the frames;
because I find that bees often build in such supers from the bottom upward. If
there is no bottom bar, one ends up with comb in the super that is attached to
the top bar of the box below.
Results
In both hives the bees take up to a couple of weeks to discover the extra
space. I see this as a good thing. It means there is no panic caused by empty
attic syndrome; ie the bees do not feel worried that the attic is empty. What
happens is that a few bees discover the space, probably comb building bees
rather than nurse bees, and comb is built at a relaxed pace. It is then filled
with honey which is ultimately capped. I have seen no tendency for brood to be
put in the supers. BUT one has to remember that, when the supers are put on,
the tops of all the combs in the main hive body contain capped honey. Nurse
bees and queens generally will not cross capped honey; they see it as marking
the limit of the brood nest. The result is a super full of capped honey in
new, clean comb. If there is not capped honey at the tops of all the combs, I
would expect the brood nest to expand upward into the super.
Is there a difference between the two hive variants? Most definitely. In the
smaller hives the bees do rearrange the brood nest. They don’t expand it into
the super but they do expand it in the main hive body, so that the super
becomes the main honey store with little honey left in the hive body. Hence,
if one harvested the super, one would be taking most of the hive’s honey. Last
year, I found that honey was stored in the hive body towards the end of the
season which meant that, by late September, the super was indeed surplus to
immediate requirements and could be harvested. But this might not be the case
in all seasons. Hence the small hive variant does not avoid the need to
exercise judgement when harvesting.
By contrast, in the large hive variant, the bees still had ample honey in the
main hive body throughout the season. So when the super was full it could be
harvested without worry.
The reason for the difference between the two hives is, I suspect, one of brood
nest volume. The smaller hive variant, at 2 1/3rd Warré box equivalents is
perhaps not quire big enough to satisfy the full potential of the bees in terms
of brood nest development. Hence, before the super is added, the bees are
somewhat constrained. After the super is added, I suspect that, as space
becomes available in the main hive body due to honey close to the brood area
being consumed this space is filled with brood and new nectar is placed in the
super. In the larger hive, of 3 ½ Warré box equivalents, I suspect the brood
area is already at a maximum and there is no pressure to expand it.
It is important to note here that different strains of bees have different
sized brood nests. The bees in my hives have relatively small brood nests. So
the larger variant of hive is plenty big enough. One hears of cases where
Golden Hives need more than 12 combs to accommodate a fully grown colony. The
same principles would apply, however; ensure that the volume prior to adding
the super is adequate. In the smaller variant I have tested, this condition
may not quite be satisfied.
As to Warrés, I have given the Warré equivalent volumes, so you can make a
comparison. I would suggest 3 Warré boxes and then add a super that is half
depth if possible. A full sized box added to the top of a 3 box stack might
trigger the empty attic response. On an existing four box stack one may well
get away with adding a full sized empty box to the top. In fact, I have done
this more than once in prior years and it was fine, except that I had only top
bars in the boxes, so harvesting was messy, as the comb was attached to the top
bars in the box below.
Hope this all helps and does not just confuse matters.
Gareth
________________________________
In the nothingness, the heart of the world has space to spin, has silence to
sing: L Vaughan-Lee
On 27 Mar 2020, at 12:56, Helen Nunn <helenmaynunn@xxxxxxxxx> wrote:
Thanks Paul. Look forward to Gareth's input! Yours was v helpful, as always.
All the best
Helen
On Fri, 27 Mar 2020 at 12:44, Oxnatbees <oxnatbees@xxxxxxxxx
<mailto:oxnatbees@xxxxxxxxx>> wrote:
It's your call. I can offer some insights on alternatives.
A more elegant solution - if it works - would be to add the box on top
without a Queen Excluder, relying on the fact that queens don't cross honey,
and there will be arcs of honey above the extant brood.
If you do go for a QE, get a plastic one you can cut to size, because it will
be made for a National which is bigger.
Bear in mind that you will cool the 2nd box, the one full of brood, by adding
a space (box) above. The bees will need to work harder (need more forage to
burn) to keep the brood warm. But Warres are well insulated.
The 2nd box would then be a permanent brood area, and one principle of the
Warre hive is that boxes with old comb gradually migrate up the stack until
harvested full of honey. My gut feeling is that old comb is good, and of
course when you harvest honey from a (normal) Warre in re-purposed brood
comb, it is full of cocoons, which makes it trickier to process, so I'm not
sure if I'm arguing for or against adding a box on top here!
Let's hope Gareth has an opinion and we can all nod and say "yes I was going
to say that".
I'm not trying it this year because my Big Change this year is orienting my
comb cold way. Change one factor at a time or you don't know why stuff
happens.
Paul