How many honey bees are there? A 2019 update.

A year ago I wrote a post titled ‘How many honey bees are there?‘, after a question on Quora got me intrigued about whether any kind of data exists on worldwide honey bee numbers. Would anyone really have counted?

Well, it turns out they have… sort of.

At the United Nations Food and Agriculture Organization website, FAOSTAT, you can now download the latest 2017 data on the number of managed bee hives worldwide across 125 countries (though not my own country, the UK!). The individual country data can be downloaded as a juicy detailed spreadsheet or the data can be visualised in interactive attractive graphs for you in the Visualize data section – this tells us that there was a worldwide total of 90,999,730 hives (up slightly from 90,564,654 hives in 2016).

© FAO, Production of Beehives world total 1961-2017, Web address: http://www.fao.org/faostat/en/#data/QA/visualize, Accessed: 14/01/19

These graphs on the top producers of bee hives over the last decade are interesting too:

Production of Beehives by region/top ten producers 2007-2017

© FAO, Production of Beehives by region/top ten producers 2007-2017, Web address: http://www.fao.org/faostat/en/#data/QA/visualize, Accessed: 14/01/19

That’s the number of hives, but how many bees are there?

So, we want to know the total number of honey bees, not just honey bee hives. Of course the number of honey bees in a hive fluctuates during the year depending on the local weather, season, available forage and the health of the colony. The species or sub-species of honey bee will also affect how many bees are in a colony. Bearing this in mind, I’ve read vastly wide ranging estimates of how many bees are in a colony; but the British Beekeeping Association (BBKA) About bees web section says ‘Typical maximum population is 35,000-50,000’, so let’s go with that.

Allowing for weaker colonies and winter reductions in numbers, as a total guess/very rough and un-mathematical estimate we might say an average of around 20,000 bees could be in each colony.

So we could estimate a total number of honey bees of 90,564,654 x 20,000, which my calculator says = 1.8199946e+12 ! Let’s round that up to two trillion.

However, this number is only for bee hives that have been counted and the data supplied to the United Nations – so it’s likely to refer to colonies being managed by beekeepers. The spreadsheet says the data is ‘Aggregate, may include official, semi-official, estimated or calculated data’. Unless someone out there was clambering up every tree or chimney counting every colony in the land, there will be many more wild colonies that have not been included. And the number of live honey bee colonies will be fluctuating all the time.

Despite the gloomy media reports about declining honey bee numbers, I hope these estimates persuade you that honey bees are not facing the same predicament as the poor Javan rhino (58-68 left). Indeed the long-term trend over the past half-century seems to indicate that the number of hives globally is increasing.

Honey bee numbers are increasing, but crop pollination demand is increasing faster

The problem is not that honey bee numbers are decreasing, but that demand for their crop pollination services has increased. This trend was picked up on by Katherine Harmon in her 2009 Scientific American article Growth Industry: Honeybee Numbers Expand Worldwide as U.S. Decline Continues. She mentions an increase of 45% in domesticated honey bee populations over the 50 years of FAOSTAT data studied by researchers Marcelo A. Aizen and Lawrence D. Harder for their 2009 Current Biology journal paper (The Global Stock of Domesticated Honey Bees Is Growing Slower Than Agricultural Demand for Pollination).

Yet despite this growth in honey bee populations, that’s still dwarfed by the >300% increase in agricultural crops that rely on animal pollination. Aizen and Harder say, ‘The main exceptions to this global increase involve long-term declines in the USA and some European countries, but these are outweighed by rapid growth elsewhere’.

How many honey bees are in the UK?

If you’re looking for UK figures… it’s not clear why, but FAOSTAT has no data on numbers of beehives in the UK after 1987; for 1986, it gives the figure 191,000.

Which will make my global estimate even more inaccurate! The UK government does attempt to collect hive numbers through the National Bee Unit – their Hive Count page says: “2017’s count indicated a total UK population of honey bee hives of approximately 247,000. Please note that several assumptions formed part of the calculations used to get derive this number. It is therefore classed as an ‘experimental statistic’.”

That compares to a count of 223,000 in 2016. So in the UK too, it looks like bee numbers are going up.

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Tis the season to drizzle

The Mite Before Christmas – a beekeeper’s poem

Twas nine days before Christmas, when all through the bee house
Not a creature was stirring, (thanks to the mouse-guard) not even a mouse
The roofs were lifted up with great care,
In hopes that the beekeeper would not need to swear.

The bees were nestled all snug in their comb,
While visions of plum-tree sugar in their heads did roam.
And queen, workers and varroa snug in the centre gap,
Had just settled their minds for a long winter’s nap.

When at the hive top there arose such a clatter,
The bees sprang from their bed to see what was the matter.
Up to their beekeeper they flew like a flash,
Showed off their behinds and made to gnash.

She spoke not a word, but went straight to her work,
And drizzled every seam, to each varroa irk.
And you may have heard her exclaim, ‘ere she hastily retreated out of sight,
“Happy Christmas to all, unless you’re a mite!”

Just a bit of winter silliness… I think that’s the limit of my rhyming skills.

Bees through palm trees

Back on Sunday 16th, with the assistance of an accomplice (my father-in-law Tom), I completed an Api-Bioxal oxalic acid drizzle on my two hives as an anti-varroa treatment. Back when it was legal to do so I used to use pre-mixed oxalic acid from Thornes, so this was my first time using Api-Bioxal. I’ve made some notes here about it, in the hopes that I’ll remember for next year.

  • The Apiarist’s Oxalic acid preparation and Trick(le) and treat posts are very useful. David recommends using a weaker 3.2% acid to sugar solution rather than the 4.4% solution given on the Api-Bioxal box recipe.
  • Next year it would help to replace the battery in my digital scales!
  • The Api-Bioxal powder can be mixed with the sugar syrup in a tall plastic milk carton before carefully transferring to the trickle container through a funnel.
  • When you live somewhere very rainy it helps to have an assistant holding an umbrella over the hive.
  • Afterwards any remaining solution can be neutralised by adding an equal amount of milk before disposing of it (at least, I hope it can – another beekeeper gave me this tip).

I’m not feeling too confident this winter as this is my first time overwintering hives in Cornwall. The bees barely seemed to be clustering at all when I did the drizzle. They have fondant on, so I need to keep an eye on that over the next couple of months. The hives are strapped down against the wind and badgers; mouse-guards are on; chicken wire has been loosely fastened round to protect against green woodpeckers. I think mostly all I can do for now is get spare equipment ready, in the hope that I will need spare boxes come spring.

Happy New Year to you and your bees.

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Book review: The History of Bees by Maja Lunde

I haven’t written for a while because it’s been a difficult few weeks. My little boy, Tommy, was very ill, first diagnosed with pneumonia and then with pericardial effusion – excess fluid around the heart. He needed an emergency operation in Bristol, a few hours away from where we live. He was in hospital nine days in the end, and is still on antibiotics, but the very kind and efficient healthcare pros in our fantastic NHS fixed him and made him into a happy, healthy toddler again.

The History of Bees by Maja Lunde – available from Amazon and independent book shops

The history of bees by Maja Lunde

The history of bees by Maja Lunde

I’ve managed to do some reading since we got back from Bristol. This book is one I found in our local library. It features three intertwined stories, from the past, present and future – a future without bees.

In Sichuan, China, 2098, Tao labours all day to hand pollinate fruit trees: a job once done by bees. Her main joy in life comes from the one precious hour she gets each day with her three year old son, Wei-Wen. But their lives are about to be hit by tragedy.

In Hertfordshire, England, 1851, William is a failed scientist turned seed-shop owner who has taken permanently to his bed. However, unexpected inspiration and hope is to come.

In Ohio, USA, 2007, ageing pro-beekeeper George struggles to accept that his son is uninterested in carrying on with the family business. Where does the future of the business lie?

All the main characters suffer difficult, devastating events, which are slowly revealed to have a common theme. At times I found the book emotionally gruelling to read, particularly the parts featuring Tao and her toddler son Wei-Wen. Luckily Lunde gives the reader some relief by ending the tale positively, with hope for the human race – if we can only learn from past history. We have already been given a warning. The book is fictional, but inspired by real events – the fruit farmers in the orchards of Sichuan do indeed painstakingly pollinate their crop by hand.

Interviews with Beekeepers

Next year I’m looking forward to the publication of Steve Donohoe’s Interviews with Beekeepers, which will feature “interviews with legendary beekeepers from around the world”.  I recommend following Steve’s blog, The Walrus and the Honeybee – his most recent post, Bee Farmers: What do you fear? is particularly fascinating. I certainly fear Chronic Bee Paralysis Virus even more than before now!

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My latest beekeeping bungle – and how I fixed it

This autumn I made the classic error of giving bees too much space. I put an eke on top of the brood box to do Apiguard treatment. Then I went on holiday. The first opportunity I got to inspect the bees after holiday happened to be a minging day, with the rain pelting down. I decided to feed them and leave without doing much else.

So the bees had lots of time and space to get up to mischief. And what my strong, feisty colony decided to do was this:

I was actually quite lucky, because the bees had built the comb mostly on the crownboard. The exception was a fairly big piece built directly on top of a brood frame. I tried to scrape this off with my hive tool, which is when the bees went bananas! This was their project, their lovely fresh new comb, and I was wrecking it. You can sympathise with their fury.

I didn’t want to leave this comb in place over winter, because chances were they would have made even more by spring. It wouldn’t have been a problem for the bees, but you can’t inspect comb like this for queen cells or disease, so it’s not ideal.

I retreated and emailed the kind local beekeeper who sold me these bees for advice (the swarm I caught this spring, by the way, had the same amount of space during the Apiguard treatment but didn’t make any extra comb!). He got back in touch with some brilliant advice. This included taking the crownboard and rogue comb 10-20 yards away and then leaving it a few hours, the idea being that meanwhile most of the bees would return home. He also suggested covering the brood box with a cloth while I tried to remove the one piece of comb attached to it.

Simple, practical tips like these are so useful. It reminded me that I had been trying to move too fast and too impatiently, rather than working with the bees’ natural behaviour. I needed to slow down to bee time and wait.

So one sunny weekend morning I upturned the roof and left it a few feet away from the hive. On top of this I placed the crownboard and its comb, covered with a profusion of busy bees. You can see a short 13 second video on YouTube. Then I covered the (now roofless) hive with a spare crownboard and walked away.

A few hours later, I returned. It had worked! Nearly all the bees had returned home and left the previously covered comb attached to the crownboard. I could easily remove the unguarded comb. And a cover cloth over the brood box kept the bees from flying up from the combs, so that I could quickly scrape the one remaining piece off. Job done.

Have you ever made a beekeeping bungle like this? What’s the naughtiest thing your bees have ever done?

Nessa

Nessa!

Other news: it’s time for my two queens to have a name. Since these are Cornish bees, their names will be: Kensa (meaning “first” in Cornish) for the swarm queen and Nessa (meaning “second” in Cornish) for the queen leading my thriving, big building bees.

For my next post I’ll write about winter preparations – which reminds me, I must get some chicken wire.

Bees through palm trees

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Notes from Cornwall ‘Bit of a do’ Beekeeping conference 2018 – Chris Park, Skep beekeeping (3.)

The final talk I’m going to write up from the joint Cornwall Beekeepers Association and West Cornwall Beekeepers Association ‘Bit of a do‘ day is Chris Park’s talk on skep beekeeping.

Chris keeps bees on organic farmland around the Oxfordshire / Wiltshire border and the Upper Thames valley. After researching and experimenting with varying styles of skep beekeeping, Chris teaches and lectures on skep making, beekeeping and beekeeping heritage / history around the UK. He says that the practice of skep-beekeeping is not everyone’s cup of tea, but it can be educational, rewarding and bee centred, in his experience creating healthy and happy stock.

I enjoyed this talk more than I was expecting. Chris comes across as quite a romantic character, into folklore and going back to old ways of doing things. He told us that before Britain was inhabited it was called the ‘sea-girt green space’, or ‘Clas Myrddin‘. And then after it was inhabited it was called the ‘Honey island’, or ‘Y Vel Ynys’. Chris has written online about what that name means to him: ‘The Honey Isle by Chris Park‘.

The history of skeps – ‘skep’ means basket and is an old type of woven beehive which is rarely used nowadays apart from for catching swarms. They were made from many materials in the past, with wicker and straw being popular options. Skeps need to be placed under a shelter to stop them getting wet and rotting. Rich men used ‘bee boles’, alcoves in a wall. Poor men used wooden shelters. To try and make them more weatherproof, skeps were dressed with cows dung and hog saliva!

Heligan Gardens bee boles

Heligan Gardens bee boles and skeps

He made some observations about the benefits of skeps to his bees:

  • The comb is renewed every 2-3 years when it collapses or the bees die out/move on, so the bees are on fresh, chemical free comb
  • There is less manipulation and hive inspections involved, so less stress for the bees
  • The bees possibly seem a bit calmer in skeps – a visiting bee inspector remarked that they were the calmest bees he’d ever seen
  • Skeps have fewer winter losses, he finds

And also about the disadvantages:

  • Time spent (my notes didn’t cover time spent on doing what – maybe on making the skeps?)
  • Difficult to inspect brood comb
  • You lose any swarms
  • More etiquette involved in where you site skeps, as you can’t predict when they’ll swarm

There are some practical things which can be done to improve on the basic dome shaped traditional design. Putting cross sticks inside supports the comb, otherwise it can fall out when you look inside the skep and then put it down again. Chris learnt this the hard way the first time he put a skep down and then heard a thump as the comb landed down too. You can use an open mesh floor or tray underneath for ventilation and catching varroa. You can also make a multi-layered brood skep with a removable super skep on top, to make harvesting honey less intrusive.

Not many beekeepers use skeps other than for swarm collecting nowadays, but there are a few people out there doing skep beekeeping still. The Dartford association have bee boles in their apiary walls. (While writing this post I discovered this 2013 article: ‘Dartford beekeeper recounts his war ordeal‘, which has a picture of William Mundy, the Chair of Dartford beekeepers, with the bee boles and skeps. He was held as a prisoner of war during the Japanese occupation of Singapore; after managing to catch a swarm he was able to donate honey to the prison hospital so that it could be used to treat wounds and burns).

If you want to read more, check out these articles by Chris for the Dave Cushman website:

Bee bole close-up Heligan gardens

Bee bole and skep at Heligan gardens, Cornwall

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Notes from Cornwall Beekeeping conference 2018 – Honey bee dances: new insights (2.)

Our first talk of last week’s conference was given by bee farmer Dan Basterfield and was all about honey bee dances and ‘The dance language controversy’.

Dan Basterfield

Dan Basterfield

About Dan:

Dan grew up with beekeeping around him and now helps to run the family beekeeping business in Devon, expanding the business and building a brand new honey farm.
He is an active member of the Bee Farmers Association, was trustee and Chairman of the International Bee Research Association, is a BBKA Master Beekeepers and Examiner; and holds the National Diploma in Beekeeping. He runs 120 – 140 double brood Modified Commercial hives, migrating between various farm crops in East Devon, and raises queens for prolific, productive and healthy qualities. Outside the beekeeping season, Dan undertakes teaching for the BBKA and NDB.

What is the dance language controversy?

Dan began by explaining that he was surprised to hear Tom Seeley make a casual comment along the lines of: ‘Of course, there’s really only one honey bee dance’. The standard information given by beekeeping books is usually that there’s at least two or three: the direction-less round dance, saying ‘go out and look for it’ for forage within 15m of the hive; sometimes included is the transition dance, for food between 15-100m away; and the famous waggle dance, giving directions for food over 100m away.

Dan decided to investigate Tom’s comment further – in fact, his talk took us all the way back to 1744!

John Thorley (1744)
“Bees certainly have a language among themselves which they perfectly understand, tho’ we do not, or at best do very imperfectly.”

I love those old beekeeping quotes. Dan used this quote while explaining that we have gained an ever better – but still imperfect – view of the dances since then. He said that what he loves about bees is that the deeper you dig, the more there is to look at, the more little tangents they send you off on.

The discovery of the waggle dance

Karl von Frisch won his Nobel prize for decoding the dance language of bees. Just two years into his research career, in 1914 the young von Frisch published a paper demonstrating that bees could see in colour, through an elegant experiment that trained bees to go to syrup on a blue square. By 1923 he had produced a paper which described ’round’ and ‘wagtail’ dances. And in 1946 he published  the book “Die Tänze der Bienen” (The dances of the honey bee), which described two dances, round and waggle. At the time it was a quite revolutionary discovery that bees had their own crude language.

Other experiments since have reinforced von Frisch’s discovery that the waggle dance indicates the direction of the nectar or pollen in relation to the sun. For instance, if you anaesthetise bees for a couple of hours, when they wake they don’t realise the sun has moved since they observed the dance, so they set off in what would have been the right direction, but arrive at the wrong location!

Fascinatingly, there are even regional dialect differences! For instance, French & Italian bees seem to misinterpret the distance when watching each others’ waggle dances.

But not everyone agreed…

The honey bee dance language debate was led by two scientists called Weiner & Wells between the late 1960s-early 1980s. They had a competing theory: odour finding, supported by experimental data.

Criticisms of the dance language included that:

  • Stingless bees use buzzing runs to recruit other stingless bees to forage; are honey bees similarly just dancing to encourage other foragers to go out, after which they find the forage by scent?
  • Why do only honey bees do these dances, when no other social insects do?
  • Many recruits fail to find the forage and return empty-stomached, are they just generally searching in response to the dance? (Dan pointed out that the bees are observing the dance in the dark, within a busy, jostling environment full of thousands of other moving bees – no wonder they make a few errors!)

The debate led to experiments being repeated. The end result was that Von Frisch’s theory was generally agreed as correct, but how odour attracts foragers became more clearly understood.

The great honey bee researchers

Dan ran through some famous names who turn up time and again in the big honey bee dance language studies. In the 1980s-1990s the round dance was redefined by researchers including Kirchner, Lindauer & Michelsen as being effective from 1m upwards.

Martin Lindauer carried on Von Frisch’s research into honey bee behaviour. Lindauer then in turn developed a working relationship with Tom Seeley, who has now also become a renowned expert on honey bee behaviour.

In 1997 Jensen, Michelsen & Lindauer slowed down videos of honey bee round dance and showed a little waggle – there is a ‘waggle phase’ present in round dances.

And in 2008 the idea that there are different dances was challenged by Gardner, Seely & Calderone in the paper ‘Do honey bees have two discrete dances to advertise food sources?‘. They concluded that the round and waggle dance are really two ends of the same  continuum, both containing information about distance and direction, with no clear switch between the two. They are just variants of the same recruitment dance.

In 2012, further experimental data was published by Griffin, Smith and Seeley: Do honeybees use the directional information in round dances to find nearby food sources? They verified Seeley’s earlier study with new experiments to show that the round dance communicates direction too. They used two feeders, one with a much stronger and therefore more appealing sugar syrup, placed at varying distances under 100m from the hive. They found that most of the bees went to the stronger syrup feeder after observing the round dance. Directional bias in recruitment was found for food sources as close as 5m from the hive.

Honey bee on echinacea?

A honey bee forager – had she watched a dance first?

 

Does all this matter? Maybe not, unless you are taking exams on honey bee behaviour! But still… I think it’s interesting to know. There is always more to find out about bees.

Questions

There was an interesting question from the audience: “Do bees communicate height in the waggle dance?” For instance, in a wood, would the dance communicate if the forage was up in the trees or down on the ground?

Don said he didn’t know! He thought von Frisch had done some experiments on this, but couldn’t remember their outcome. We also don’t know how bees communicate finding food above them in the hive, for instance when a feeder is put inside. This seems to lead to general robbing in the area.

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Notes from Cornwall Beekeeping conference talks – Bit of a Do 2018 (1.)

The two local Cornish associations (the Cornwall Beekeepers Association and West Cornwall Beekeepers Association) put on a great ‘Bit of a do‘ day of talks and trade stands. I’m going to write up Dan Basterfield’s talks on ‘Honey bee dance language’ and ‘Reading bees’ and Chris Park’s talk on ‘Skep beekeeping’ over the next couple of weeks. Here’s a few photos from the day.

The first exhibit as soon as you walked in was an Asian hornet nest and special hornet proof ‘Ultra Full‘ suit made by BBWear. The hornet is on everyone’s minds at the moment as we’ve just had three sightings in Cornwall – two nests have been destroyed in Fowey now and a single hornet sighting confirmed in Liskeard. We are an Asian hornet hotspot 😦

Asian hornet proof suit

Look closely at the nest in this photo and you can see a couple of little orange heads poking out, these hornets died just before they could hatch. The nest itself is quite remarkable, it’s amazing what insects can create. Like a wasps’ nest it is very fragile and light.

Asian hornet nest

Spot the heads

There was a lot of discussion about the Asian hornet in the final Q&A session, including the best type of bait to use and whether monitoring traps should be put out.

Most of the five panellists (Dan Basterfield, Chris Park, Anne Rowberry, Dr Peter Kennedy and Will Steynor) were in favour of using monitoring traps in spring and checking these daily to remove any beneficial pollinators. Dan Basterfield goes as far as sticking his hand in the trap to let any European hornets climb out on him! Some of the panellists were in favour of using killing traps in the autumn as they believe most of the insects trapped at that time of year will be wasps.

Different bait seems to be successful in different areas. Dr. Peter Kennedy, a field ecologist, mentioned that in Jersey protein based baits have not been that successful. There they use a specialist wasp attractant – the name sounded like ‘Sectera’ (edit: thanks to Di and Chris for confirming in the comments that it’s Suterra). In Spain the hornets seem more attracted to fish based baits – prawns are often used. There has been speculation that the hornets may have reached the island of Majorca on fishing boats.

There was also a question about a proposal in the new Agriculture Bill that bee imports should be banned and that all beekeepers should be registered. Dan Basterfield, who is a commercial bee farmer, felt that banning imports would not stop bees being brought in within people’s pockets. Anne Rowberry, a master beekeeper from Avon, was in favour of banning imports, particularly as the small hive beetle is now in Italy, where many of our imported bees come from. One of the panel noted that Jersey has compulsory registration but there are still unregistered beekeepers there.

This was the winner of the Gadget competition – a useful stand for all your equipment during inspections.

Gadget competition winner Bit of a Do 2018

 

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