I have noticed on many occasions that bees will return from foraging in large numbers, when there is an imminent storm. This is sometimes quite startling if there are no obvious signs of rain. I have saved myself several soakings by taking heed the bees returning activity. This sudden rise in returning bees is only a few minutes before the rain strikes. (I have also seen this on many occasions, the first, soon after staring beekeeping, when the front of several hives were covered with bees. The sky didn't look too threatening, but a short time later it hammered down with rain and the bees taught me something I will never forget. R.P.)

How do they do it? Our own senses need obvious signs to make such predictions. Honey bees can sense changes in air pressure, but these are often not directly linked to the storms. The hairs on the bees backs are sensitive and would be affected by electrostatic build ups in weather clouds.

Jerry Bromenshenk (now retired from the University of Montana) reports that bees respond strongly to solar radiation... not simply to the intensity of the light, but a more rounded response. Whether this is a direct stimulus, or a secondary effect due to the influence of solar radiation on the plant's ability to produce nectar, is unknown. Under good flight conditions (reasonably calm and warm with flowers in blossom), the overall flight activity of a colony is reported to almost synchronize with changes in solar radiation levels.

Jerry suspects that bees sense an array of weather variables. So, if the wind is picking up, the temperature is dropping, solar radiation is decreasing and barometric pressure is dropping it adds up to a storm on the way. There are no reasons why they would make decisions about whether to fly out of the hive, or return, based on only one variable. His data and models indicate that sometimes bees just do not know accurately, anymore than we can always make the right prediction. In other words, some days, all of the colonies race home before the storm, or all of them ignore the clouds on the horizon and the storm sweeps around, missing the yard. However on some days, some of the colonies race home, others do not, and yet others mill about as if they can not quite decide whether to make another trip or not.

Jerry's data stems from 7 years of running bee hives that are equipped with flight counters and simultaneous weather measurements, up to fifty hives at locations in MT, MD, TX, Mississippi were studied. (I'm unable to locate information. Can anyone help please? R.P.)

Originally written by Dave Cushman. Edited by Roger Patterson.

Page created 09/04/2002

Page updated 01/12/2022