Within-day variation in continuous hive weight data as a measure of honey bee colony activityWilliam G. Meikle1, Brian G. Rector1, Guy Mercadier1 and Niels Holst2
1 European Biological Control Laboratory, USDA – ARS, Campus International de Baillarguet, CS 90013 Montferrier sur Lez, 34988 St Gely du Fesc, France
2 University of Aarhus, Faculty of Agricultural Sciences, Department of Integrated Pest Management, Flakkebjerg, 4200 Slagelse, Denmark
Received 30 April 2008 – Revised 19 August 2008 – Accepted 29 August 2008 - Published online 19 December 2008
Abstract - Hourly weight data, from 4 honey bee hives placed on balances linked to dataloggers, were divided into two independent parts: (1) daily running average and (2) detrended weights, obtained by subtracting the running average from raw data. Weekly changes in running average weights, WCRAW, were correlated with food store changes but not adult or brood weights. Detrended weights showed daily fluctuation due to water and foraging bee movement and were modeled using sine curves, which fit all weekly subsets. Adult and brood populations, measured independently, were expressed as colony consumption rates via published per capita rates, and those consumption rates were correlated with sine amplitudes. Amplitudes were more sensitive to hive activity than WCRAW and unlike WCRAW detected high activity when foraging success was masked by high consumption Estimating food store changes with WCRAW and colony consumption with amplitudes reveals hive growth and activity without disturbing bees.
Key words: Apis mellifera / hive weight / consumption rate / foraging activity
© INRA, DIB-AGIB, EDP Sciences 2008