Results of international standardised beekeeper surveys of colony losses for winter 2012-2013: analysis of winter loss rates and mixed effects modelling of risk factors for winter loss
Date
2014Author
Van der Zee, Romée
Brodschneider, Robert
Brusbardis, Valters
Charrière, Jean-Daniel
Chlebo, Róbert
Coffey F, Mary
Dahle, Bjørn
Drazic M, Marica
Kauko, Lassi
Kretavičius, Justinas
Kristiansen, Preben
Mutinelli, Franco
Otten, Christoph
Peterson, Magnus
Raudmets, Aivar
Santrac, Violeta
Seppälä, Ari
Soroker, Victoria
Topolska, Grażyna
Vejsnæs, Flemming
Gray, Alison
Metadata
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This article presents results of an analysis of winter losses of honey bee colonies from 19 mainly European countries, most of which implemented the standardised 2013 COLOSS questionnaire. Generalised linear mixed effects models (GLMMs) were used to investigate the effects of several factors on the risk of colony loss, including different treatments for Varroa destructor, allowing for random effects of beekeeper and region. Both winter and summer treatments were considered, and the most common combinations of treatment and timing were used to define treatment factor levels. Overall and within country colony loss rates are presented. Significant factors in the model were found to be: percentage of young queens in the colonies before winter, extent of queen problems in summer, treatment of the varroa mite, and access by foraging honey bees to oilseed rape and maize. Spatial variation at the beekeeper level is shown across geographical regions using random effects from the fitted models, both before and after allowing for the effect of the significant terms in the model. This spatial variation is considerable.