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 90 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 20 inches (50cms) in diameter and 32 – 36 inches ( 80 – 90cms) long. The cavity is 12 inches (30 cms) in diameter and is fitted with top cover boards and a floor hatch. Cavity volume is approximately 55 – 65 litres.
Log hives can be placed high in trees or on the ground.
In July 2017 I inspected this log and found that the bees had grown comb to the base of the log and were still very active.
The log can also be mounted on legs which still allows inspection from underneath.