Monitoring colony phenology using within-day variability in continuous weight and temperature of honey bee hives

Continuous weight and temperature data were collected for honey bee hives in two locations in Arizona, and those data were evaluated with respect to separate measurements of hive phenology to develop methods for noninvasive hive monitoring. Weight and temperature data were divided into the 25-h running average and the daily within-day changes, or detrended data. Data on adult bee and brood masses from hive evaluations were regressed on the amplitudes of sine curves fit to the detrended data. Weight data amplitudes were significantly correlated with adult bee populations during nectar flows, and temperature amplitudes were found inversely correlated with the log of colony brood weight. The relationships were validated using independent datasets. In addition, the effects of an adult bee kill on hive weight data were contrasted with published data on weight changes during swarming. Continuous data were found to be rich sources of information about colony health and activity.