Hive Scales : 29 WEIGHTWATCHERS FOR BEES!
Hive Scales
Sandra Kordić Evans H
ow much honey did your bees make last year?
How heavy was the swarm that left? What levels of stores do your colonies have for overwintering? Weight is one of the main biological components of a colony of bees and is a source of information that is not only intrinsically interesting but also greatly instructive.
History
Beekeeping was an important economic activity in the ancient world and weights referring to yields of honey from hives have been documented. Aristotle’s contemporary states that a hive will yield to a beekeeper between 5 and 14 kg of honey. The fact that weight information was constrained to honey production is hardly surprising as spring-loaded scales did not come into use until the nineteenth century
and manoeuvring a beehive onto a balance scale would have been a formidable task. Nonetheless, much is written through the ages referring to light and heavy hives (harvesting only from light and heavy hives and leaving the medium weight ones to overwinter with all the stores) thus beekeepers must have been hefting for as long as they have kept bees. Skeps normally had a small loop at the top to allow them to be lifted easily or hefted to judge the weight of the honey inside. Even today, hefting is recommended as a valid tool for evaluation of a colony’s strength and particularly as a way to assess stores before overwintering. However, hefting accurately is a skill that takes time and practice to learn and an error of a few pounds could affect a colony’s survival. Precise weighing of a beehive
offers much more than just data on honey production. Dynamics of weight gain through nectar fl ow and weight loss as a result of stores
Hive scales in the Kiev Beekeeping Museum (Prokopovych Beekeeping Institute)
consumption is a very good indicator of a colony’s strength, health and productivity. Hive weight has been used by scientists to study the honey bee colony’s annual cycle (Seeley), to quantify nectar availability (Downs and Ratnieks) and measure honey bee colony activity (Meikle, et al), to name a few.
Arnia Hive Scales Figure 1. Arnia hive scales April 2015 Vol 97 No 4
www.bee-craft.com
Hive scales (Figure 1) are one of the most useful part of the Arnia electronic beehive monitoring system. Unlike most hive scales on the market, which are of a platform design, our scales’ doughnut shape was conceived with open-mesh fl oors (OMF) in mind. OMFs are used as part of integrated pest management (IPM) to control varroa and as an aid in ventilating the hive, both for temperature and humidity regulation. Impeding the ventilation and offering a
ladder for varroa to climb back into the hive was among the considerations when it came to product design. Our scales are low profi le, thus not requiring adjustment in the height of the hive stand and their capacity is 160 kg (for those legendary harvests).
Nectar Flow and Dearth
During a nectar fl ow, an
increase in weight is seen as bees return with nectar, but the scales also reveal the weight drop during the night as the bees process the nectar and the water evaporates. This is demonstrated in Figure 2 (overleaf), where the addition of honey supers can also be noted as 7 kg vertical increases in weight. Furthermore, in the same fi gure, based on the weight data, the precise time the swarm left the hive can be identifi ed and weight of the
Photos and illustrations by Huw Evans
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