We find that we are watching the weather forecast with increasing interest. What seemed like endless Summer days have started to feel crisp and fresh and night time temperatures have sunk to single figures. Ordinarily, we wouldn't take much notice except to switch to a warmer duvet at night and go back to wearing jackets for work. This year it's different because we have to think about the bees.
According to The Authorities, the temperature should be over 17C if you want to open the hive to examine the bees. If you have to examine the bees below this temperature, it's recommended that you work quickly and only do essential tasks to minimise disruption to the bees. They shouldn't be examined if the temperature is below 10C.
Individual bees adopt the temperature of their environment but they can generate heat through muscular activity. At 8C an individual bee freezes. Apparently therefore, when the average temperature falls below 18C, they begin to huddle together in the hive forming a ball amongst the frames. When average temperatures reach 13C all the bees are in this cluster which enables the bees to regulate their temperature by expanding and contracting the cluster and eating more or less honey so they can engage in wing fanning activity which produces heat.
All beekeepers want to avoid Chill Brood which shows as white cells in the honey comb and results from the larvae being exposed to the cold for too long. These larvae never hatch.
Our bees show no signs of starting to cluster yet but we have mended the out door thermometer and hung it up where we can see it from the kitchen window. It is taking noticeably longer for temperatures to climb in the morning now and temperatures seem to be falling faster in the evening.
Wind and wind chill
If you have to open the hive on a colder day, it's best to choose a calm day, at least then wind chill does not make the bees even colder. Even on a warm day, if the wind is gusting it seems to disturb the bees. Our apiary is almost completely surrounded by hedges, raspberries, shrubs and a fence which together act as a wind break and filter but we have postponed opening the hives several times because there was a brisk wind. For flying, wind direction is more important than wind speed. A strong wind blowing straight along the runway is perfect but a lighter wind blowing across the runway makes taking off and landing a challenge. Gusting wind, especially wind that is gusting and changing direction makes taking off and landing really hazardous, at least for people with my limited experience. Personally, I like laboratory conditions for landing, i.e. no wind at all. Often here the wind drops in the early evening and we have a still period but I am certainly paying more attention to wind speed in the weather forecast and the dilemma is do we wait for the wind to drop and run the risk of the temperature dropping too?
Clouds and rain
The standard bee examination templates all seem to include a space to record whether it is cloudy. That must be for a reason. It transpires that bees seem to know when it's going to rain and they don't like thunder or rumbly vibrations of any sort. We chose our apiary site to keep the bee hives well away from the lawn mower and we seem to have got that right as the bees take no notice if it. We had heard horror stories of bees chasing lawn mowers.
Our records of cloud conditions aren't illuminating so I think we will have to dust down P's aero weather text books and accurately record cloud conditions to learn more about how clouds affect bee behaviour.
All of this makes me realise it was a big mistake not to buy the weather vane I saw at yesterday's country show. There were several designs - a witch flying on a broomstick ( you might think that appropriate), a chicken ( my favourite) and a tractor, all complete with little wind cups to indicate (but not measure) wind speed as well as showing wind direction.