ONBG meeting, 12th Dec 2015: Hive design

Some of the tradeoffs and variants discussed

Some of the tradeoffs and variants discussed

Fifteen folk gathered at Gareth’s house to discuss the design of hives, and organising a Warré hive building workshop for the group next year. We were joined by Matthew Mercy, a professional Warré maker (website: zorbanet.com)

Gareth gave a detailed and exhaustive presentation on hive construction and the tradeoffs between bee / beekeeper preferences. A key point was that in the last year or two, people have begun questioning all kinds of received wisdom…

Tree beekeeping

Recently, European beekeepers have been trying traditional techniques preserved by the Bakshirs of Eastern Russia, who shape forest trees and create deliberate cavities. This takes perhaps 60 years, but can be simulated by hoisting log hives up a tree as shown in this video by Matt Somerville and John Haverson. Note how thick its walls are – about 6 inches of solid wood.

These Russian tree hives have shown that some assumptions are just that; bees adapt nest structure to the available cavities. The premise that bees always store excess honey at the top of the hive is now realised to simply be an artefact of most hives having bottom entrances! These Russian tree colonies have top entrances cut in their tree hives and honey is stored and harvested from below the brood area, the brood being near the (top) entrance. (Brood is always next to the entrance, and this determines where everything else is packed, as we realised in this blog post.) Gareth remarked, “this has literally turned beekeeping upside down!”

Seeley’s classic studies in the 1970’s seemed to show that bees prefer tree cavities with bottom entrances, but Seeley now thinks that was an artefact of how most nests he located were at head height. Later he learnt to look up, and found there are more nests way up in trees! It is not known if high-up cavities naturally have top or bottom entrances. At this point Graham interjected – he is a tree surgeon – that top cavities, typically formed when a branch falls off, invariably rot downwards, so they have top entrances. Within 2 days this information was being repeated on discussion groups: the serendipity of bringing the right experts together.

Mary's log hive

Mary’s log hive

Re-examining tree colonies has also drawn attention to the fact that bees seem to like narrow tall cavities with really long combs. Gareth intends experimenting with thinner, taller Warrés next year.

Mary has been making a hive by hollowing out a tree trunk. She reflects: “Next time I’d change the orientation of the top bars, remove less of the rotten wood in a longer log.  Maybe not have top bars, let the bees build where they want.  A window would be good.”

Derek Mitchell‘s recent work comparing hive types has shown how “you can’t have too much insulation”; both for survival, and because easier temperature control allows the bees to use their energy to make more honey. Six inch thick tree walls are ideal; Warrés and skeps are pretty good; but thin walled Nationals require a lot of fuel (honey) to be used to keep them warm in winter. People have experimented with making octagonal hives to reduce cold corners, but it’s remarkably complicated to do – some complex joints which are tricky to seal, the bars need to be different lengths, a slight error in an angle and things don’t line up, etc. In really cold climates, people usually just put triangular wedges in the corners of rectangular hives to form a more compact, octagonal core cavity.

Natural nest positioning

Bees like their nests 15 feet up or more. There are many reasons – out of the way of some predators, for example. What most people aren’t aware of is, temperature above head height. Cold air sinks. Frosts and mists tend to form at ground level. By being up a tree, the daytime temperature may be a little cooler, but many frosts are avoided and day/night fluctuations are greatly reduced.

Woods for hives

Some woods are really bad for hives. Plywood, for example, doesn’t breathe, and the inside of the hive ends up damp and mouldy as the bees’ breath condenses on it. Question: does this mean you should not seal the outside of a hive with paint or linseed oil? Answer: no, that’s OK, the important thing is that moisture (vapour) can migrate through the wood so the mass of the wood does not get waterlogged.

Pine and fir are cheap and often used for hives, but be aware that they need painting to extend their life in rain. Use a paint which doesn’t contain heavy metals and be sure the wood is seasoned, or it will warp and paint won’t adhere well.

Larch is strong but Matthew warned it is nasty stuff to work with, it creates many small sharp splinters and irritant dust.

Cedar is preferred for making hives for many reasons. It doesn’t warp. A given thickness of cedar is a better insulator than almost any other wood, yet it is lighter than pine or larch. It is rot resistant and lasts decades in Britain’s damp climate. When sawn, it doesn’t splinter. Cedar is, however, corrosive to screws unless you use good quality stainless steel ones.

Top bar design

Warrés can suffer from comb going across bars instead of along them. Gareth has experimented with thinner bars and confirmed bees follow sharp edges as guides. With a wide bar they can get confused and start using one side (the corner) as a guide! They don’t seem to need wax starter strips along edges, in fact they sometimes strip it off before building their own comb. So he is now using bars along the lines of the right hand image below.

The standard bar used in Warrés, a wide flat strip, is probably not ideal and may be a cause of bees not expanding into new boxes (stuck box syndrome, a.k.a. false floor syndrome). This may be due to the bees looking down and seeing mainly wood ‘floor’ rather than space (see left hand photo below); or it may be due to thermal or ventilation effects. People are now experimenting with narrow bars tapering to a sharp edge at the bottom.

Helen's design uses pegs to space the bars, allowing easy spacing adjustment

Helen’s design uses pegs to space the bars, allowing easy spacing adjustment and avoiding squashed bees

Helen demonstrated her bar design. This goes in a modified horizontal Top Bar Hive which uses Warré style gaps between bars, with a hessian ceiling, above the bees.

Windows

Matthew has found most people want windows in their boxes – he even finds himself converting returned plain boxes to windowed ones, which he’s happy to do. We examined different designs of window for Warré hives. Gareth has developed one which uses fewer parts / cuts, the tradeoff is that it views the flat side of one comb, and most people prefer to see the edges so they can judge how full a box is. We were advised to use glass, not perspex for windows – it doesn’t warp, and perspex is a nightmare to cut.

The meeting concluded with a discussion of how to organise a Warré hive building workshop. We settled some details – we have enough people committed to this to make it viable; we’ll use kits made from cedar from Matthew Mercy; we will aim for this taking place in February. We are in the process of sorting out a suitable location.

So in summary…

  • Entrances don’t have to be at the bottom of a hive, honey doesn’t have to be at the top
  • Thick walls are best
  • Cedar is the best wood to make hives from
  • Thin top bars with a sharp edge underneath give fewer comb problems
  • Matthew Mercy makes very high quality hives

Many thanks to Gareth and Lynne for generously sharing their house, and all the cake!

Post Script

Following this meeting, the workshop was arranged for April 2016 in association with Matthew Mercy and the Sylva Foundation. The course is now full, but contact us if you would like to be added to a “wait list” for future workshops.

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