It has been said that no form of beekeeping can be natural and the term seems to irritate the hell out of some beekeepers. However the phrase has been chosen with good reason, emphasizing how far some orthodox beekeeping practices have come from the ways bees would behave in the wild, ‘naturally’.
Dead tree trunks are typical of the kind of place that honeybees choose for their home. Tall and thin with excellent thermal properties, the hollow tree trunk provides space for them to build their comb down as far as they need, allowing them to expand and contract as required. The position will be high off the damp ground with plenty of air circulation.
As soon as we put them in a square box, close to the ground we start to compromise their ideal des res. Place rectangular frames inside on which they are to make their comb and again their natural instincts are denied.
The comb bees build has been likened to an organ in its own right. Not only do they make cells different sizes according to whether they will lay a worker, drone or queen but it seems they can communicate with vibration sent over this flexible structure. It is however extremely fragile and makes extracting honey from the hive and inspection more difficult.
Rectangular frames that can be lifted out of the hive make inspection and honey removal much easier. But the foundation dictates cell-size, not the bees, and enclosing the foundation in a rigid frame prevents subtle vibrations being passed on.
Natural beekeeping hives use top bars, equivalent to the top of a frame with no sides or bottom. The bees can make cells the size they want and the vibration isn’t compromised as much as with a solid frame. Top bars can be lifted out for inspection and honey extraction although it is more delicate affair!
The most popular top bar hives at the moment are the vertical Warré and horizontal top bar hive.
You can see how a Warré (left, with thanks for the photo to the Natural Beekeeping Trust) mimics a tree trunk by stacking high relatively small but thick-sided boxes. It is possible to have top bars only in the top box and allow bees to make long combs however many beekeepers place top bars in each box to keep it manageable.
The Golden Hive or Einraumbeute if you prefer, is a long box (below right, with thanks for the photo to the Natural Beekeeping Trust). The ‘Golden’ refers to the golden section on which the measurements are based. Typically long frames are used rather than top bars. The hive is used more commonly in Germany and it and its parts can be difficult to find here. For a good discussion about this hive see Biobees forum.
The relatively newly designed Sun Hive goes even further towards providing bees with a home that respects the choices they make naturally. It is made from straw like a skep so can achieve a circular shape. It is suspended in a shelter so keeps warm and dry and airy. To see the amazing construction see Sun Hive.
I hope this provides a useful summary of the choices open to natural beekeepers but for a comparison of these hives including the practicalities, see Comparison of Natural Beekeeping hives.