Bees warm to sunny weather

Honey bees, quite like ourselves, work best in weather conditions suited to their temperament.

Honey bees, quite like ourselves, work best in weather conditions suited to their temperament.

They like quiet, warm and sunny weather: when strong winds or rain are present, or when it happens to be cold, the bees very sensibly stay inside their hives and wait until there is some improvement.

But the bee, it is said, often knows exactly what kind of weather to expect. Its wisdom is partly encapsulated in the old rhyme which tells us that:

"When bees to distance

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wing their flight;

The days are warm and

skies are bright;

But when their flight

ends near their home;

Stormy weather is sure to

come."

They are particularly sensitive, it seems, to thunderstorms. When a thunderstorm is imminent, the bees in a hive become agitated and aggressive, a form of behaviour which some scientists believe is related to the increased electrical activity in the atmosphere which precedes a severe thunderstorm.

However, other weather parameters also affect their equanimity. Indeed, studies have shown that aggression in bees is "positively" related to temperature, humidity, barometric pressure and solar radiation, and "negatively" related to wind speed.

This, in plain language, means that bees are allegedly at their most aggressive on hot, sunny and humid days when there is little wind. And it is surprising that this should be so since these are the very conditions suited to their principal task, the gathering of nectar for honey.

Light winds, for example, are important for this purpose. The normal cruising speed of a bee is about 15 m.p.h. to 20 m.p.h.: winds in excess of these values cause serious difficulties because, although the bee can cope with a strong headwind by flying more vigorously, in doing so it consumes much of the sugar it has gathered by converting it to energy. The yield of honey is, therefore, very much reduced.

Rain is also a great enemy since a bee in heavy rain runs a significant risk of drowning.

Perhaps, more importantly, the rain affects its raw material, the nectar, which in many varieties of flowers is washed away or so diluted as to make it unprofitable for the bee to collect it. At best, in damp conditions the bee must make many more journeys to and from the hive to facilitate the manufacture of a given quantity of honey.

The flow of nectar is also affected by temperature: the higher the temperature, the more nectar becomes easily available. This may explain why bees seem to find it unappealing to work at temperatures below 16C or 17C.