Honey bee vibration monitoring using the 805M1 accelerometer

The use of accelerometers to obtain information on the state of honeybee colonies has several advantages over sound recorded by microphones, in that (i) accelerometers can reside in a honeybee hive for several years with a negligible effect of propolis coating (ii) they are particularly good at monitoring the low frequency signals which form a large part of the honeybee communication processes, and (iii) they sense a physical property, the vibration, that is probably far more relevant to them than sounds. One example of accelerometers allowing the observation of specific vibrational communication signals has been reported for the ‘whooping signal’ (doi: 10.1371/journal.pone.0171162). The vibrational amplitude is also dependent on the local environment/substrate and this has been demonstrated to be a strong indicator of an active queen (doi:10.1371/journal.pone.0141926). These previous reports have used ultra-high performance accelerometers (Brüel and Kjær, 4507) which also require separate signal conditioning electronics before the vibrational data can be logged; this represents a very expensive arrangement that precludes wide deployment. In this work we demonstrate that the 805M1 single axis analogue output accelerometer, that incorporates a piezo-ceramic crystal with low power electronics in a shielded housing, can be used to monitor honey bee activity and requires only a low cost microcontroller with an audio shield to log the data. We present high quality accelerometer output signals for both individual bee pulses and long term amplitude monitoring using this affordable measurement system. The signals appear of similar quality to those acquired with ten fold more expensive equipment.