The Bees' Needs (part 3)
In the previous two posts I considered pollen and nectar - now the focus is water. Again, I'm looking at honeybees, because that's what I know about!
Like all living creatures honeybees need water for their own metabolism. It is also vital for the welfare of the colony as a whole. In order for the brood (baby bees) to develop properly the temperature within the brood area must be kept at 35°C ±0.5°C (although brood can survive between 32-36°C), and the relative humidity has to be between 35-45%. If the temperature within the hive reaches 47°C then the comb will collapse spelling disaster for the colony.
In order for the optimum temperature and humidity to be maintained, the bees instigate an ‘air-conditioning’ system bringing water into the hive which then evaporates, keeping the temperature down and the humidity stable. There are occasions when there is too much moisture in the hive, however. This usually happens when there is a high water content in the nectar which is being collected. Again, bee ‘air-conditioning’ is switched on - some bees will fan their wings near the entrance of the hive to increase the air circulation and aid evaporation.
How much water do honeybees need?
Water is also a constituent part of the food that is given to the brood. Unlike pollen, which can be stored in cells, water has to be collected as required. At the start of the season in particular, water is also needed to reconstitute the store honey; bees do not ‘eat’ honey in its concentrated form - it has to be diluted. All of these factors mean that the amount of water a colony may need at any time can vary considerably. Estimates fluctuate between 120ml and 4 litres per day, although it has been reported that in Australia during a heatwave, a 90 litre trough of water was emptied in less than three hours by bees from 150 hives. Just to give you an idea of just what a feat that was, one bee can carry approximately 25mg (this is equal to 0.025ml - about 1/200 of a teaspoon) of water at a time!
Access to water
Although bees will fly considerable distances to find water it's better for them if they can find water close to home. A pond with a pebbled edge is a luxury which you don’t need to aspire to, although it will attract no end of wildlife to your garden. Bees will naturally take water from wet surfaces such as pebbles, soil, grass and even wet washing, rather than from an open surface. They cannot land on water without breaking the meniscus, (the ‘taut’ surface of the water), and since they are not good swimmers, they need a good solid surface to land and walk on in order to access the water.
In addition, in warm weather a strong colony will require several pints of water a day, so a good, clean, regular supply is essential. Any water-tight container filled with pebbles or crocks and topped up with clean water is ideal, but I have found that a poultry feeder with some pebbles in the canal at the bottom where the chickens would normally drink from is just the job. A word of warning though: as far as collecting water is concerned bees are creatures of habit - once they detect and adopt a source of water it is very difficult to persuade them to go elsewhere.
Well, that concludes my round-up of the bees' needs. More about bees over the next few months.
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