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
Honey Bee's Ability to Detect Weather Variation
This sudden rise in returning bees is only a few minutes
before the rain strikes.
How do they do it? Our own senses need obvious signs to make
such predictions. They 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 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.
Originated... 09 April 2002