Brood Nest Shape In Honey Bees
The actual nest shape of honey bees, within a set of frames that are themselves within a box (or set of boxes), changes relative to geographic latitude and varies from an American (or Rugby) football lying on it's side in hot regions (so that there is a larger surface area on the top for heat dissipation).
In lowland, temperate regions the nest is roughly spherical.
In more Northern and higher altitudes the nest is Rugby ball or egg shaped, but standing on it's end (thus giving minimum heat loss from the smaller top surface.
The shape of nests in UK varies from the South coast to the North of Scotland.
The relatively broad Langstroth frame should be more suited to hot areas and in cold northern areas it would seem that a Jumbo Langstroth or a British 14" x 12" (future link) or Unified frame would be more suitable so that the nest would be kept to one single set of frames.
During 2004 on the Irish discussion list in a thread about standard sizes of frame, I made some comments about nest shapes that occur in various places in the UK. Some variance was found, between what I said and what was found in Cornwall by James Kilty. My information came from notes that I made in conversation with Beowulf Cooper, some of which were later published in 'The Honey Bees of the British Isles'. As much time has passed since my original conversations with Beo, I reproduce the message thread and follow it up with quotes from the book. My comments are in blue text
David Smith asked... What is the preferred shape (if any) for feral nests ?
There is plenty of evidence that shows a shift in shape... In UK midlands it tends to be ovoid with the longest dimension horizontal and an aspect ratio around 2:3.
In South of UK the longest dimension is horizontal and an aspect ratio might be nearer to 1:2.
Somewhere near to Newcastle on Tyne, nests are roughly spherical and further North than this the longest dimension becomes vertical.
James Kilty replied...
Interesting that in my 14" sq frames, in the spring I can see the preferred shape readily and it is mostly ovoid with the long dimension vertical. Some colonies keep this shape throughout the season, though it is more usually like a half ellipse, going right down to fill the frame at the bottom. Others fill the frame completely, in the centre at least, so are constrained by the frame shape.
Now this really is different to my observations...
I have never used the 14 x 14 (unified) frame myself, nor have I ever seen any Amm bees on 14 x 12 frames, but I have seen them on B.S. Commercial frames and B.S. deep frames.
I was under the impression that James's bees were good specimens of Amm (by morphometry and behaviour) but I have found that the better specimens of Amm limit the bottom of the nest quite strongly with a pollen arch all the way underneath the nest as well as above. I have also seen exactly the same in some Irish Amm stocks. The only cases where I have seen bees building the nest out to the woodwork have been with hybridised bees. The Amm bees hardly ever hit the woodwork and sometimes their total mid season nest only occupies six or seven frames (normal deep).
Having said the above, I should explain that one of my selection criteria has been the evidence of an underneath pollen arch. My choice of this characteristic is not so much that I have done any research on it, but my information came from Beo Cooper and I thought it was based on Ruttner's work (at a time when I might not have been listening to all that he said) :-)
Perhaps I have influenced what I have seen by my own selection.
Quotes from the book[edit | edit source]
Nest Characters... Page 26
17. COMPACT BROOD PATTERN. Besides the shape of pollen stores referred to earlier, the native brood pattern is more compact: generally spherical in bees of lowland areas and southern districts, or taller than broad in those of hilly areas and northern latitudes. Continental and Mediterranean bees frequently show a broader than tall pattern in summer: in South Africa one frequently sees brood nests twice as broad as they are tall. The spherical and tall patterns are evidently related to the need in our climate to conserve spring and summer heat, and the broad pattern to an equal need to dissipate it in hot climates.
BROODNEST SHAPE This has also been discussed in Chapter 3. We may usefully distinguish one nest shape, as observable on the face of a comb from the centre of the broodnest, common to most strains early in spring, and four different nest shapes at the peak of brood production in about early June. The early season pattern is roughly spherical or triangular, with the apex pointing upwards. At brood peak, the shape may be spherical or "normal", tall (i.e. up to one and a half times as tall as broad), very tall (over one and a half times as tall as broad), or broad (broader than tall). Broodnests which are exaggeratedly broad are seldom found in the British Isles, even in imported strains.
The queen excluder, though it may curtail the upward spread of brood, does not prevent one from spotting a taller-than-broad pattern. If the bees favour a tall broodnest and there is not room for it in the broodchamber, they will at first leave an area in the supers free of honey and pollen where they would like to have brood. In a prolonged honeyflow this space may eventually get filled up.
The pattern of brood cells within the broodnest area is also of interest. The keeper of Italian bees likes to see a "nice frame of brood" filled to the edges with a slab of brood of similar age. This is the product of a fast-laying, often prolific queen. Native queens who lay more slowly and temper their rate of laying in the nectar dearth will create a concentric pattern of brood of different ages, often dotted about with enclosed pollen cells.
Conclusions[edit | edit source]
Several things are evident... I believe that I was wrong to say "In South of UK the longest dimension is horizontal and an aspect ratio might be nearer to 1:2.", but I am confused as to why I have it fixed in my mind even after 20 odd years. I am not used to seeing colonies that are so prolific as to reach the side bars of the frames and so I am used to seeing a more strongly defined shape of brood pattern than most, as an example Beo's picture above (plate 10 from the book) shows two frames, the like of which would only occur in my area with hybridised bees. The weather in Cornwall is a good deal warmer and sunnier than where I live, which could account for difference in colony size, but I do not think that smallness should automatically be associated with Amm type bees as many colonies in Ireland belonging to Micheál Mac Giolla Coda show larger nest bulk than I am used to seeing and Micheál's Galtee bees are probably the purest examples of Amm known.