Thermal experiments by Derek Mitchell of Basingstoke indicated that straw and log hives could be much more thermally efficient than modern thin walled hives. Better insulation reduces stress and energy consumption, maintaining warmth during winter; it also helps to prevent overheating in hot weather.
Our observations and research indicate that tree cavities are long and narrow with small restricted entrances as well as thick walls. Cavity volume is typically between 40 and 60 litres.
The heat will be usefully concentrated at the top of the cavity during the construction of a new nest. Colonies will be able to build long uninterrupted combs and to sit under their honey stores during the winter; thus avoiding isolation starvation.
Fashioned from trees blown down in storms or felled when at risk of falling, our log hives are a minimum of 18 inches in diameter and 32 – 36 inches ( 80 – 90cms) long. The cavity is between 10 and 12″ in diameter and is fitted with top cover board and rain cover and then a removable board is rebated into the bottom. This allows for inspection of colony growth and any debris.
Bees like to be off the ground. Ideally in trees 12-15 ft off the ground but the log can also be mounted on legs which still allows inspection from underneath.