22 Apr 2012

Comparing hives 7: History and Legislation

This post forms part of a series on hive comparisons.

Here we are setting aside discussion of ancient or traditional honeybee hives and limiting ourselves to so-called 'modern' hives. I note that the use of that word has implications! This is not to say that 'pre-modern' hives were not 'natural', in many cases their design and construction was much closer to the origins of the bee's natural home of hollow trees, caves and rock cavities. But when we are talking about beekeeping in (typically) the urban/suburban environment as hobbyists, we recognise that the practicalities of our urban environment and the existing legislation lead us to only consider modern hives.

Some history
The history of modern hives can be traced back to the 1700's as apiarists sought alternatives to traditional hives, such the skep. In those days, skep beekeepers extracted honey and wax by first killing the colony with (for example) sulphur fumes. Skep beekeeping is still practiced today, but without the extermination. The general idea of the modern hive was to allow beekeepers to extract honeycomb from the hive without killing the colony.

The main issues were that traditional hives did not allow easy access to the inside of the nest and that the bees attached their comb to the walls of the container. Both limited the ability of the beekeeper to removed honey. At some point, moveable frames were introduced into hives which encouraged bees to build their comb within them, rather than attaching it to the hive walls. Development of framed hive continued in various directions until the 1800's saw a rise in the scientific approach to understanding the world.

Ultimately, in the 1852, Rev L. L. Langstroth patented his self-named removeable frame hive based on (his or another's) discovery of 'the bee space'. This is a gap of around 6-8 mm and related to the size of the body of the bee. It was noted that gaps inside the hive which were:
 - smaller than the bee space were eventually 'glued' together with propolis and made the parts (for example frames and lids) difficult to remove;
 - larger than the bee space were joined by comb;
 - within the range of the bee space, they were left open.
Hives designed with the bee space had major advantages for beekeepers (though not necessarily for the bees, as it happens) in terms of convenience, scalability and honey yields. Langstroth's hive remains the predominant type in use to this day in much of the 'westernised' world.

In response to the various threats facing bees, the Natural Beekeeping (NB) movement has formed in the last decade. It is both a philosophy and a practical approach to beekeeping which aims to be bee-friendly/bee-centric in order to (aside from any other moral obligations) allow bees to build immunity through their own natural processes. Many NB practitioners generally view framed hives as a part of the (esp. disease) problem facing bees.

Framed hives
  • Allow, possibly encourage, beekeepers ('beeks') to intervene in the life of the hive by opening it up and pulling out and (re)moving sensitive frames of brood. This challenges the colony, the bees and their young on a number of levels.
  • They also deny the bees the ability to fasten their comb to the roof or the walls of the nest (hive). Essentially, combs constructed in frames are islands floating in a sea of air and do not allow the bees to form heat and scent retaining galleries (dead ends) which retain these properties. See this article by Thur on why this principle of NB is important.
  • Are (generally .  . . ) a requirement if you wish to use a honey extractor and this promotes the use of frames with wires and foundation - more non Natural practices which we posted about here.
So, NB beeks consider (often promote) the use of alternatives to the framed hive. If one does not use frames, then top bar hives (TBHs) are the next step towards 'natural'. This is because TBH's generally allow the bees to build the comb in a way which suits them rather than suits us. The original (non framed) Warre and the Kenyan hives are contemporary hives supported by NB beeks. The Warre derived in the 1950s and the Kenyan lineage arguably going back to ancient Greece.

Which brings us to beekeeping legislation. Most legislation (and esp. true for Australia) says that beekeepers must keep their bees in hives with 'easily removable frames' which 'break no comb' when being removed.
  • WHY would the legislation require this? The answer is - to make it easy for beeks and  government inspectors to check the comb (specifically the brood comb) for diseases.
  • WHY do hives need to be inspected for diseases? Because diseases not only threaten bees, they threaten our food supply and the beekeeping industry. Fair enough.
  • BUT - from early the 1900s, observers of beekeeping (such as Steiner - who BTW in 1920 predicted that our modern method would lead to the downfall of the bee in 80-100 years . . .) increasingly made a link between the increased prevalence of diseased bee colonies with the introduction and widespread use of framed hives. Some propose that some of the more serious diseases (such as AFB) were unknown before the advent of framed hives.
  • SO - are we now in a situation where a significant factor (framed hives) in the causation of disease is also legislated as part of the solution to these diseases? In other words, are we are locked into a vicious cycle.

The legislation requires (in Australia) the use of frames, but does not specifically ban the use of top bars.
  • The Langstroth hive - no problem - fully complies with the legislation - in theory. However, in practice, the Australian built version does have some issues with bees building ladder comb between the frames and that does require breakage.
  • The Warre TB hive - when used with top bars will produce combs which are joined to the hive walls and (under ideal conditions) are arguably removeable for inspection - but does require the combs to be separated from the walls with a special tool. Not what the law requires.
  • The Warre framed hive - is very similar to the Langstroth in box/frame design, just that it's square (see post 1 in this series). It is fully complient with the law, at the compromise of using frames - but the bees benefit from other aspects of Warre's design (such as the sealed roof and square box).
  • The Kenyan hive - is a pure TBH - with no frames. The reason is has sloping sides is to encourage the bees to leave a bee space around the comb and not attach it to the sidewalls of the box. For the most part, this is successful. However bees will sometimes attach a few cm of the top of a heavy honeycomb to the walls. Does it comply with the spirit or the letter of the law? It is an open question. In 2012, in New Zealand - Kenyan hive beekeepers were required to fit fames into their hives. Not an easy thing to do, given the shape and the fact that they are occupied by bees . . .

Given the above discussion:
  • The framed Langstroth and Warre hives are equally acceptable under the Australian legislation.
  • The top bar Warre is probably not.
  • The Kenyan is in a grey area.

13 Apr 2012

Comparing hives 2: Frames & Comb

This post forms part of a series on hive comparisons.

After the size (volume and box dimensions) and the shape of the hive which we discussed in Part 1, the next level of consideration is the size (area) of comb supported by the hive.

This is important because, in the end, the hive boxes only exist to provide shelter and support for the bees and they live on the comb which they construct inside the walls. So the amount of comb they are able to build within the hive has an impact on:
  • the number of bees it can accomodate;
  • the ability to breed and grow the colony within the season;
  • the amount of honey and other resources they can store;
  • the amount of energy required to keep the cavity warm;
  • the overwintering characteristics.

Aside from the area of comb, there is also the consideration as to how that comb is fixed within the hive, there are two possibilties (within the hive types under discussion, Langstroth, Warre, Kenyan):
  • Top bars - these are simple, horizontal bars of wood held in place in a rebate at the top of the hive box.
    The bees attach the top of the comb to the underside the bar and are free to build downwards in any way they wish. They may or may not attach the sides of the comb to the sides of the hive boxes. They usually leave a space at the bottom of the comb, just above the floor of the hive or the bars of the next box below.
  • Frames - this is a four sided frame, usually (but not always) made of wood. It has two lugs at the top which allow it to be suspended from the rebate a the top of the hive box. The frame hangs suspended inside the box, with a 'bee space' all around it - rather like a folder in a suspended filing cabinet.
    The bees attach the top of the comb to the (inside) top of the frame, the sides to the (inside) sides of the frame and the bottom to the (inside) bottom of the frame.

Which hive has which?

Langstoth hives were designed specifically for use with frames.
Pic. Newbees

Warre hives were designed for use with top bars (lower pic) - but also had an alternative design specification to accomodate frames (upper pic). In the top bar version, the bees generally attach the comb to the hive box walls.
Pic. Biobees 
Kenyan hives were designed for use with top bars. Some people are experimenting with frames in Kenyans. With top bars, the bees generally do not attach the comb to the sides of the hive, except for combs full of honey where they may make a small side attachment at the top.
Pic. Berkshire Farms Apiary
Comb area comparisons
  • Langstroth - per frame: 0.173 m2 - per box: 1.41 m2 - per hive: 4.32 m2
  • Warre - per top bar: 0.12 m2 - per box: 0.96 m2 - per hive: 3.50 m2
  • Warre - per frame: 0.108 m2 - per box: 0.97 m2 - per hive: 3.84 m2
  • Kenyan - per top bar: 0.125 m2 - per 30 bar hive: 3.5
  • These figures count both sides of the comb - i.e. the total area of cells.
Note that:
  • For typically configured hives of 4 boxes - both variants of the Warre hive actually accomodate 90% of the comb area that the much larger Langstroth hive does.
  • The Kenyan provides 81% of the area of the Lang.

We can now make a comparison of the hives' dimension characteristics by combining the results of volume with the results of comb space by calculating a ratio. That ratio is the amount of hive volume per unit area of comb.

Why is that important? The more 'non-comb' volume there is in a hive, the more energy and resources (bee time) the bees have to apply in order to keep the comb, brood and themselves warm. More energy use = less honey stored and more stress on the bees.

The ratios in order of merit of 'hive volume efficiency':
  • Warre (top bar) - 19.69 litres of hive volume per m2 of comb face;
  • Kenyan (top bar) - 23.57 litres;
  • Warre (frames) - 23.96 litres;
  • Langstroth (frames) - 25.67 litres. 30% more than the top bar Warre . . .
This means that, inside the Warre, the bees have much less volume to maintain at a given temperature.

Why is it that framed hives are much less volume efficient than top bar hives? Two reasons:
  • The wood of the frame takes up a remarkably large volume inside the box. The frames inside a typical Lang take up 11.5 litres of space - that's around 10.5% of the volume. The bees need to keep that volume of wood warm.
  • Frames require a bee space around each side (see Post 7), otherwise the bees with propolise of comb over any gap and attach the frame to the hive box wall, rendering it immobile. In hollow trees, the bees build comb upto the edges of the hollow.
Interestingly, the Kenyan performs on a par with the framed hives in this regard. This is because the bees (usually) leave their own bee-space around three sides of the comb. This is a design feature of the Kenyan (the sloped sides) to allow the combs to be easily removed (easier than the Warre TB at least). The Kenyan may compensate for this lower performance because, as a horizontal TB hive (HTBH), it has different heatflow charateristics to a vertical TB hive (VTBH) such as the Warre?

11 Apr 2012

Comparing hives 1: Dimensions & Shape

Common hives - Langstroth | Kenyan | Warre
One could arguably distill Natural Beekeeping (NB) thinking and approaches into two categories:
  1. The beekeeping equipment we use - mainly the hive type.
  2. The beekeeping methods we use - how we interact with the bees and the hive.
The intention of this post is to tease apart some of the (sometimes thorny) issues related to selecting a hive. This is especially relevant to beginning beekeepers. Once you select a hive type, you are likely to undergo training and invest in equipment. This can lead to a financial and perhaps psychological 'lock-in' to that system. This may be OK if you are happy with your initial choice, but not if you later decide you should have gone in a different direction.

Perhaps we should aim to make informed decisions with good information, rather than with wisdom received from someone already locked into a system?

We'll review (within the context of Victoria, Australia) the following aspects of the the three most commonly used hives (Langstroth, Warre, Kenyan):
  1. Dimensions/shape
  2. Frames & comb
  3. Yield
  4. Availability
  5. Cost
  6. Usability
  7. History & Legislation
In this post, we will cover the first topic and the others will be written under their own post.

1. Dimensions/shape
The most relevant dimension of a hive is its internal size, primarily its volume (we use litres) because that is the overall space a colony has to work with. For conventional beekeeping this is possibly the only consideration. The larger the volume, the more space for bees/comb/honey storage.

From an NB perspective we are very concerned with hive temperature and heat retention within the hive. The inside of a hive needs to be warmed to (and then maintained at) a suitable temperature, around 35 degrees C for the brood area. This requires the bees to generate that heat using nectar/honey to vibrate their wing muscles. The larger the volume, the more stress the bees are under in order to maintain the required temperature. There is another factor here and that is how the hive is configured - if there is lots of empty space above the brood area, stress is increased dramatically.

For Natural Beekeeping, there are two additional concerns with dimensions beyond volume:
  1. The shape of the box (i.e. when viewed from above)
  2. The dimensions and area of a section that shape
If, as Natural Beekeepers, we wish to replicate the bees' natural environment as closely as possible. If so, then we are looking for something that mimics the internal hollow of a tree (usually a vertical tree, but it could be a horizontal/fallen tree or log - see diagram below). This would be a hive forming an internal cylindrical shape and this requires a box which is square, rather than rectangular, when viewed from above. This shape fits the tendancy that bees have to work within a spherical shape when rearing brood or clustering for winter.

A typical 'wild' honeybee nest in its natural envirnonment
The size (area) of that square shape is also important because as the brood area moves down a hive box, the bees have to heat a greater volume (of air and comb). If the area is large, they have a greater volume to heat, per cm of depth. The dimensions (the cm measure of the square sides) is important because it should closely match the natural clustering of the bees. There are a number of reasons for this. For example, in winter, bees cluster together for warmth and eat their way upwards into their honey stores. In a square box (of appropriate size) they fill the square and this minimises heat losses. It also ensures that all honey is accessible to them from below. In a rectangular shaped box, in winter, there is unused/cold space to each side of the cluster, the honey there is not readily accessible and there is also the potential for condensation to form on the hive walls.

Let's compare the internal (a single box) dimensions of the three hives:
  • Langstroth
    - 'deep' box - 46.4 cm (l) x 30.7 cm (w) x 24.3 cm (h) = 34.6 litres
    - 'ideal' box - 46.4 cm (l) x 30.7 cm (w) x 14.6 cm (h) = 20.8 litres
    - this is a frame (only) hive
  • Kenyan
    - 110 cm (l) x 38 cm>13 cm (w) x 30 cm (h) = 82.5 litres
    - note that the useable volume can be infinately varied using the follower boards
    - the is the Phil Chandler (www.biobees.com) varient of the Kenyan
    - this is a purely top bar (only) hive (TBH)
  • Warre
    - The TBH version - 30 cm (l) x 30 cm (w) x 21 cm (h) = 18.9 litres (60% of the Lang)
    - The framed version - 33.5 cm (w) x 33.5 cm (h) x 20.75 cm (h) = 23.3 litres (68% of the Lang)
Please note though that for the framed hives, these are the GROSS volumes.  Actual usable (i.e. can build comb or otherwise reside in) volumes are lower because the wood of the frames takes up a percentage (9.1% for the Lang and 7.7% for the Warre) of the space inside the hive. This is very important because it means the bees are warming up space which is unusable to them.

Other heat retention related points to volume and hive design and are:
  • The amount of space within that volume available to build comb - it's an insulator.
  • Whether the comb can be formed into 'gallaries' which are sealed - they trap heat.
We'll cover these in more depth later posts.

Based on the above discussion, the hives perform as follows, in order of preference:
  1. Warre - a square section box, with a small volume. Vertical stacking. Higher frame volume efficiency.
  2. Kenyan - a trapezoidal shaped box, large volume, which can be finely managed with 'follower boards'). Horizontal direction.
  3. Langstroth - a rectangular shaped box with large volume. Lower frame volume efficiency.
The Warre - a hollow tree trunk?
Inside the Kenayn - a fallen log?
Langstroth's box -  a natural shape for bees?