Estimating Colony Strength
Lexikon
Colony strength refers to the approximate number of bees a colony comprises at a given point in time.
Colony strength refers to the approximate number of bees a colony comprises at a given point in time. Estimating it is one of the basic skills in beekeeping, because it shows whether a colony is strong enough for overwintering, whether it is inclined toward swarming, or whether it needs additional support such as feeding or uniting with another colony.
In practice, colony strength is often estimated roughly via the occupied comb spaces: one looks down between the frames and counts how many spaces are densely occupied with bees. As a rule of thumb, the values of the Liebefeld Estimation Method are often used, according to which a fully occupied comb side in Zander size carries around 1,000 bees, but around 1,400 bees in Dadant size, because the comb area there is larger.
Colony strength fluctuates considerably over the course of the year. For wintering in autumn, values of roughly 5,000 to about 13,000 to 15,000 bees are considered the usual range, with markedly weaker colonies regarded as critical for overwintering. In early summer, at the peak of colony development, strong colonies can by contrast comprise 25,000 to well over 40,000 bees. These ranges differ somewhat depending on the source and bee race, but agree well in order of magnitude.
A common beginner's mistake is judging colony strength after a single, brief check in cool weather. At low temperatures, bees often sit drawn together more densely or in several layers on top of each other, so that the number of occupied spaces can underestimate the actual colony strength. An assessment in mild weather, when the bees are distributed more evenly over the combs, is more reliable.
Quellen (3)
- Überprüfung der Schaetzmethode zur Ermittlung der Brutflaeche und der Anzahl Arbeiterinnen in freifliegenden Bienenvoelkern, Imdorf et al. 1987, Agroscope / Schweizerisches Zentrum für Bienenforschung
- Lehrgang zur Erfassung der Volksstärke, Imdorf & Gerig, Agroscope / Schweizerisches Zentrum fuer Bienenforschung
- Die Liebefelder Schätzmethode: Das Gefühl mit Verstand untermaürn, Schweizerische Bienen-Zeitung