Summer starvation warning

The National Bee Unit has just issued a starvation alert for parts of the UK. Here in Oxfordshire, we’ve had a great start to the year, the bees have boomed, hives were heavy with stores early in the year and swarms began about a month early. There are many flowers visible to the eye. So why do we need to worry?

The short answer is lack of rainfall. For some weeks we’ve had relentless sun and heat, which is lovely up to a point, but plants need water to make nectar. Without rain, that blossom is empty. Conversely, in some years we have excessive rain extending throughout peak forage periods, which can hinder nectar production in key plants.

And even if a hive has honey stored, bees can’t eat pure honey. They need to dilute it to make it digestible, so they need a water source not just for cooling but to use their stores. Do your bees have a handy water source? Is it topped up?

It is essential to prevent bees getting so short of food that they become lethargic, as experienced beekeepers report that once such a state is reached, they sometimes don’t recover even if forage becomes plentiful again.

Should you feed your bees?

Typical forage availability in rural Oxfordshire. Areas vary – Northumberland’s moors would show a single peak (heather) in August.

Well adapted local colonies are tuned to the forage availability of the plants around them. Rather than breeding at maximum rate all the time, they have a more cautious breeding pattern and ramp up the queen’s laying a few weeks before the main nectar flows – so there will be an appropriate number of workers for the coming glut.

However between the main nectar flows are gaps, and although there is still a fair amount of harvestable blossom in June, there are now a lot more mouths to feed, who were raised to take advantage of the Spring forage. So there is a danger that any stores built up in the first boom will not quite be enough to carry the colony through June. Particularly if the beekeeper harvested honey from the colony.

I’ve built up my apiary using local bees and I use natural selection to weed out unfit colonies. My approach is: if an established colony doesn’t survive, they had a poor strategy for survival in this area. So I don’t feed established colonies. This is why I don’t use Buckfasts or Italians – they are used by migratory beekeepers who move their hives round the country which ensures a continuous nectar flow throughout the year. If I used them they would overbreed for the forage accessible from a stationary garden, and often need feeding in dearths.

Swarms and casts

My strategy is different for swarms and particularly for the small secondary ones (casts). These have not usually had time to build up stores for dearths, particularly if they emerged late. A prime swarm caught in April may not need feeding but a cast caught in June probably will. By feeding them in their first year, I conserve their genetics and have a chance to evaluate whether they are a good match to the local area – though I try to primarily collect swarms from long established feral nests.

Hefting

Sometimes you can see capped honey through a hive window, but if not, hefting can give you an idea of the weight distribution inside. If you heft a hive and it is heavy with stores, it doesn’t need feeding. (Bees and wax weight very little.) To heft, put a veil on and:

  • Horizontal top bar hive: try lifting opposite ends of the hive, just lifting 2 legs at once, an inch above ground is sufficient. If it is very light at both ends, that is a bad sign. One end should feel noticeably heavier than the other due to honey stores.
  • Warré hive: these are trickier to gauge by feel as they are narrow. Take the roof off (it’s quite heavy) and tip it at each side. Maybe you can feel a difference – I often cannot. So I use luggage scales for an accurate estimate of weight on each side. A difference of 3kg or more is healthy.

What to feed bees

First, for any non-beekeeper readers: never feed shop-bought honey to bees. It can carry diseases such as American Foul Brood spores. If you want to feed an exhausted bee, give it sugar water.

When feeding a hive in summer, don’t overfeed. The micronutrients in nectar and honey are lacking from simple sugar syrup. A conventional beekeeper might also say, you don’t want your honey crop to be made from excess sugar syrup as such honey does not have much taste!

A good recipe for nectar-substitute would be:

  • 0.5 litres water
  • 1kg white refined sugar (i.e. a strong 2:1 feed because we are trying to emergency-feed them quickly – nectar is usually half this strength)
  • 100g of honey from the same apiary
  • A teaspoon of soluble vitamin C (found in nectar)
  • Optional: teaspoon of lemon juice (alters pH of mix – though the Vit C does this too)
  • Optional: nettle sap (micronutrients)
  • Optional: flower scent e.g. crushed lavender, to help the bees locate the syrup in the darkness of the hive

But in an emergency, the key ingredients are sugar and water.

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2 Responses to Summer starvation warning

  1. Emily Scott says:

    The grass round here looks so dry and parched. Luckily my bees live next to a river.

    Like

  2. Many people don’t realize the impact incessant heat, drought, and lack of water has on any living creature. It’s hard enough on the bees dealing with cooling the hive and keeping the humidity high enough for brood rearing. Add to that dearth and the amount of energy needed to gather even more water for rehydrating honey to prevent starvation. Last year after a brutally hot and dry summer and early fall we experienced a number of fall abscondings locally. “Hunger swarms” is the term I found in a few older publications. Then I also found it in a new book where it was mentioned that it may occur with or without food being present. I thought this was of particular interest as it seems to imply that the bees sense the direness of the conditions and may leave during such situations.

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