On a hot summer night, there is a special treat you can do in the moonlight. Take a walk by your beehives and hear them cooling the hive, smell the evaporating nectar, and feel the power of the bees ventilating their home.
A new study out from Harvard’s School of Engineering and Applied Science studied the framework of environmental influences and bees signals that help the colony cool the hive. Detecting the ventilation strategy was half the fun.
Read the article here, see How bees stay cool on hot summer days
European honey bees (Apis mellifera) live in large congested nest cavities with a single opening that limits passive ventilation. When the local air temperature exceeds a threshold, the nests are actively ventilated by bees fanning their wings at the nest entrance. Here, we show that colonies with relatively large nest entrances use an emergent ventilation strategy where fanning bees self-organize to form groups, separating regions of continuous inflow and outflow. The observed spatio-temporal patterns correlate the air velocity and air temperature along the entrances to the distribution of fanning bees. A mathematical model that couples these variables to known fanning behavior of individuals recapitulates their collective dynamics. Additionally, the model makes predictions about the temporal stability of the fanning group as a function of the temperature difference between the environment and the nest. Consistent with these predictions, we observe that the fanning groups drift, cling to the entrance boundaries, break-up and reform as the ambient temperature varies over a period of days. Overall, our study shows how honeybees use flow-mediated communication to self-organize into a steady state in fluctuating environments.The Royal Society: Collective ventilation in honeybee nests