Tag Archives: hefting

Weighty matters

During irregular midwinter visits to the apiary you need to check if the hive entrances are clear and to determine whether the colony has sufficient stores for the remaining winter. The rate at which stores are used depends upon the number of bees in the colony, the strain of bees, the temperature and whether they’re rearing brood or not.

The apiary in winter ...

The apiary in winter …

The easiest way to ‘guesstimate’ the level of stores is to gently lift the back of the hive an inch or two, and to judge the effort required. Beekeepers call this ‘hefting‘ the hive. Colonies should feel reassuringly heavy. After all, you’re only actually lifting half the weight of the hive – the front remains on the hive stand – and if that feels light it might indicate a problem.

Be gentle

The hive will be full of torpid bees on a freezing cold winter day. On really cold days the wooden floor of the hive might actually be frozen onto the stand. Don’t force it and jar them. And if you can gently lift one side, don’t just drop the hive back onto the stand afterwards. Ideally you want to judge the weight of the colony without the bees being disturbed at all.

Be gentle ...

Be gentle …

However, judging the weight takes experience. Is it a lot less than last week? Is it less than it should be? In the picture at the top there are 5 hives, only two of which (those on the closest stand, and above) are comparable. You can’t easily compare hives if you have only one or if they’re not made of the same material.

But that doesn’t mean you shouldn’t try. Over time you will get experience for what feels OK, and what feels a bit light.

And if any do feel dangerously light then you need to intervene and give them more stores – in the form of fondant – as soon as possible. At least, you need to intervene if you don’t want to risk them starving to death. I’ll discuss topping up the fondant in a future post.

Technology to the rescue

You can get a much better insight into changes in the weight of a colony by, er, weighing it. Luggage weighing scales are widely available, cheap and accurate. With a little ingenuity you can fashion a means of attaching them to the side of the floor. I drilled a 6mm hole through the side runners of the floor and securely tied an eye bolt to some strong polypropylene attached to the scales.

In a similar way to hefting a hive, lift each side carefully, but this time note the weight and add them together. It’s helpful to use scales which automagically record the maximum stable weight. Note the weight down in your hive records and see how it compares over time.

As before, be gentle with these colonies in winter. Don’t go bouncing them up and down. The bees will not appreciate it. With care you can weigh the colony and barely disturb them at all.

What? You want even more accuracy and even less work? Look at the hive monitoring equipment from Arnia, SolutionBee or others. These use under-hive scales hooked up to a mobile phone to upload weights (and lots of other data) for analysis from the comfort of your armchair.

At a price  😯

Frugal bees are better bees

Different strains of bees use their winter stores at different rates. ‘Black bees’ (Apis mellifera mellifera, or Amm) are well known for being frugal. In contrast, some Italian strains chomp through their stores like there’s no tomorrow (and if you don’t feed them, there won’t be).

My Heinz strain 1 of locally-reared bees exhibit variation in the amount of stores they use. The two comparable hives on the same stand in the top picture both started the winter packed with stores. By Christmas one of them remained reassuringly heavy, whereas the other one was feeling light and was given a fondant supplement.

All things being equal, I’d prefer my bees use less rather than more. When the time comes to rear queens later in the season the thrifty colony will be favoured.

Some beekeepers take a harder line than this … if a colony can’t store enough to get it through the winter they let it starve and so allow ‘natural selection’ to operate.

I’d prefer to have the luxury of an additional colony in Spring. I won’t rear queens from it and I’ll minimise drone brood to prevent it contributing to the next generation. Instead, I’ll build it up in the spring and then split it for nucleus colony production in late May or early June.

Unnatural selection perhaps, but it’s a solution I’m comfortable with.

Given the choice, I suspect it’s what the bees would prefer as well 😉

Frosty apiary

Frosty apiary


 

Bring out your dead

It’s midwinter. There’s very little to do in the apiary. Time is probably better spent planning and preparing for the coming season (and drinking tea in the warm).

However, there are a few jobs that shouldn’t be forgotten.

Let the undertakers do their work

The first job is to ensure that the hive entrances are clear. This allows bees to readily exit and re-enter the hive for ‘cleansing’ flights during warmer days. During these days the bees will also remove some of the many corpses that accumulate during the winter. If the hive entrance is clear these can be removed easily. If the entrance is blocked they continue to build up and – on warm days – you can hear a panicky roar of trapped bees from inside the hive.

Corpses at hive entrance ...

Corpses at hive entrance …

Don’t worry about the loss of these bees. It’s what happens. The colony goes into the autumn with perhaps 30,000 adult workers. Four months later, at the end of December, there may be only about one third of this number remaining. Brood rearing is limited during this period (and at times non-existent), but picks up in early January.

Attrition rate

Even assuming no brood rearing, this means that 150-200 bees a day are expiring. If they are rearing brood, even at a significantly diminished rate, it means that more than 200 bees a day are dying.

For comparison, 300 bees is about a ‘cupful’ … the number you’d do a Varroa count on. Imagine dropping a cupful of dead bees on the hive floor every day for a fortnight. Unless these corpses are cleared away the hive entrance gets blocked. This is what the ‘undertakers’ clear.

On calm warm days you can find the corpses littered on the hive roof, or in front of the entrance, dropped there by workers carrying them away from the hive.

Since ‘flying’ days may be infrequent at this time of year and/or bees have other jobs to do, like go on cleansing flights or collect water, they may not carry the corpses very far … don’t be alarmed by the numbers of corpses around the hive entrance.

Don't count the corpses ...

Don’t count the corpses …

A bent piece of wire to the rescue

I mainly use kewl floors with a dogleg entrance slot (see the top image on this page) that reduces robbing by wasps and negates the need for a mouse guard. I’ve fashioned a simple piece of bent wire to keep the entrance slot clear of corpses on my irregular visits to the apiary during this time of the year.

Kewl floor unblocker ...

Kewl floor unblocker …

I’ve only ever had problems with large, double-brood colonies after very extensive cold periods (~4 weeks with hard frosts every night) when the entrance has got blocked. One colony I managed to save despite it showing signs of Nosema after the bees were trapped for several days.

It takes just seconds to check that the entrance is clear and gives considerable peace of mind. If you use mouseguards it’s worth checking the holes aren’t all blocked after an extended cold period.

Next week I’ll discuss the other important winter check … are there enough stores remaining to stop the colony starving?


Colophon

Anyone familiar with Monty Python will recognise the post title.

This was one of the well-known scenes from Monty Python and the Holy Grail, a 1975 film parody about the Arthurian legend and a low-budget quest for the Holy Grail. The film usually ranks close to the top in surveys of the best comedies of all time, with another Monty Python film (The Life of Brian) often topping the tables.

In the film there’s a further scene (A self-perpetuating autocracy) which involves a political argument with interesting parallels between the public perception 1 of a colony of bees and the biological reality. This is topical, with the recent Deloitte report on women in leadership roles holding back the careers of other women they perceive as a threat.

Perhaps a topic for a future article … ?

Queen bees and the self-perpetuating autocracy.