As an experienced beekeeper and representative for the LBKA this is a question that I have frequently been asked for advice on over the years. It’s a question with no clear cut or easy answer but one which I have a burning desire to find answers to and hope to explore in a future PhD project.
Beekeeping at height has increased significantly over the past decade as more and more city dwellers opt to keep bees on their roof tops and terraces. Keeping bees on roof tops in built up environments where space at ground level is in short supply makes sense as it utilises dead space. There are also added security benefits of siting hives off the ground and out of reach of thieves and vandals.
At the height (excuse the pun) of this craze are the increasing number of corporates opting to keep bees on their premises under the misguided notion that doing so in some way helps saves the bees which they perceive to be under threat and is good for the city environment and biodiversity. It is widely believed that being seen to help honey bees demonstrates good social and environmental responsibility and boosts a company’s green credentials.
Firstly, we need to establish that Honey Bees in the UK, Europe or indeed on a global level are in no immediate danger of going extinct. Despite what the sloppy journalists working for the tabloid press would have you believe there is no impending honey bee apocalypse on the horizon.
In the UK honey bee numbers have recovered from declines beginning in the post War 50’s and now stand at around 250,000 managed colonies (excluding N Ireland) with amateur beekeepers up from 8,500 a decade ago to 25,500 in 2015 (source: DEFRA and BBKA 2016). Across Europe colony numbers are up by an estimated 7% in the 5 years from 2005 to 2010 (Breeze et all 2014) and in other parts of the world significant increases in colony numbers have been witnessed.
In North America the US Department for Agriculture announced in 2015 that national colony stocks were at a 20 year high, exceeding numbers of hives before the first instances of Colony Collapse Disorder were reported (USDA 2015). China has seen increases of its numbers of managed hives as fruit producer’s battle to overcome the expensive need to hand pollinate Nashi Pears and other orchard fruits. New Zealand has significantly increased its national stocks of Honey bees in response to the unprecedented demand for Manuka Honey – a product which 20 years ago beekeepers in New Zealand struggled to give away until it was discovered to have miraculous medicinal benefits. When we separate honey bees from other bees (which are under serious threat) it’s clear that they are not in immediate danger and that managed honey bee stocks are again at healthy levels. Concerns about fulfilling pollination demands stems from our own human population’s ever growing need to grow more food.So corporates wanting to place hives on their roof tops to help bees is not really needed as honey bees are actually faring well. Their solitary cousins however are not so lucky.
Many cities now house substantial numbers of honey bee hives. NYC reportedly has around 450 hives, Washington DC around 200 and Metro Atlanta almost 5000! (pers comm with American BKA’s 2015). Many European cities accommodate healthy numbers of managed hives.
In London stocks of honey bees stood at 4218 colonies as of December 18th 2014. In 2015 this rose to almost 5000 registered colonies, many of which are to be found in the city centre parts of which contain an average of 13.5 hives per km2 (National Bee Unit 2016). With all these honey bees in a very built up environment already short on flowers, pumping more and more colonies into the city does not make sense and in no way benefits biodiversity or helps the environment. There are already sufficient honey bees to pollinate the cities trees and adding more can stretch floral resources thinner.
There is also the question of how increased numbers of honey bees places wild pollinators under greater pressure through resource competition. Wild bees have physical and behavioural adaptations which allow them to avoid competition with other bee species including honey bees but when resources are in short supply competition may be forced upon them. There is also the possibility that high densities and movements of honey bees could pose a disease risk to wild bees. Nosema, Deformed Wing Virus and parasites associated with honey bees are now frequently found in other species (Goulson & Hughes 2015).
Companies could be doing more for the environment and biodiversity by supporting planting initiatives and helping wild bees through the installation of solitary bee nesting habitats. In doing so they would be earning real green kudos.
So now we’ve established that opting to keep honey bees isn’t the huge boost to one’s green credentials corporates often assume it would be – that doesn’t stop some of the semi commercial beekeepers from telling them it is so when cash is involved. Herein lies another conflict.
‘cash for bees’ brigade
Most beekeepers have their bee’s welfare at heart and want to see their bees thrive and do well, not least because they will get a better honey crop from them and if you’re a commercial keeper then this honey represents an income. In towns and cities however a growing number of beekeepers now make more of their income from running training events and from offering managed hive solutions to corporates. They’ve been branded with the term ‘cash for bees’ beekeepers.
The problem with accepting money to maintain hives for extremely wealthy corporate clients who think nothing of blowing a few grand on improving their corporate image and impressing their wealthy clients is when money comes into play ethics and common sense often go out the window.
Beekeepers aware that the bees won’t do terribly well and make as much honey as they could do if kept at more sensible locations may turn a blind eye to the obvious as the honey is not theirs and they are usually being paid a far more lucrative income just for tending the hives, than if they were keeping bees for honey production. Conflicts of interest soon creep in.
Sums of £2-3000 per year per hive are not uncommon, some cash for bees keepers are charging £500 just for a risk assessment – something which usually takes very little time and effort for an experienced person. Some ‘cash for bees’ beekeepers also claim to have cracked the bees to flowers ratio and offer a flimsy pseudo-scientific analysis of potential locations to justify positioning bees in less than desirable sites. Many also claim to be sustainability experts when there academic background and real professions lie elsewhere. Take the time to ask what field of research their PhD studies were in. Chances are it was in something like theatre and not ecology or biological life sciences.
Often those offering ‘cash for bees’ services also emphasis the fact that they are part of a beekeeping association or perhaps even an association official. Beekeeping associations seldom endorse individuals or provide references to potential corporate clients. Furthermore official representatives of associations are bound by their constitutions to declare conflicts of interest and not to abuse their positions for financial gain. Membership of a BKA also does not carry any weight in terms of the person’s skill and competence as a beekeeper. The RSPB has over 1 million members but that doesn’t make them all expert ornithologist does it? Ask to see a keepers bee basic, honey bee management or general husbandry certificates which are British Beekeeping Association issued qualifications in cognition of one’s ability as a beekeeper. You can read more about beekeeping qualifications here: http://www.bbka.org.uk/learn/examinations__assessments
The problem is most corporate and social responsibility managers for these corporations know very little about bees and are very gullible. If a ‘cash for bees’ keeper turns up in a bee suit acting like an expert on the subject and tells them honey bees are in decline, in trouble and they will be helping them, the CSR manager is likely to believe them even when it isn’t true and front cash for bees.
Seeking Green Kudos the easy route can backfire spectacularly!
In the last few years numbers of corporates in the city acquiring bees has increased significantly. A group called ‘In Midtown’ once boasted the ambition to house the largest number of urban roof top hives in London which encouraged many neighbouring businesses to invest in bee hives. Many prestige hotels have also acquired bee hives so that they can sell their honey for ridiculous prices in their gift shop or charge a bomb for it in a dish served in their fancy restaurants. The problem is there is always a wealth of filthy rich customers willing to pay for the experience and this drives demand for bees on hotel roof tops. For example in New York the Waldorf Astoria has 6 hives 20 storeys above street level in view of the Empire State building for which they charge guests $1800 to witness a hive inspection lasting up to an hour followed by honey themed treats in the restaurant. Experienced keepers in Manhattan advise against siting bees higher than 6-8 storeys as the wind speed and turbulence makes it difficult for the bees to fly and not profitable from a honey production point, yet many keep bees for corporates at dizzy heights because cash is involved. The same is true in cities across the western world.
There is a real danger however of these prestige establishments lust for green kudos back firing on themselves as has been witnessed in 2015 when a well known prestige hotel in London had to have its 2 hives destroyed after recommendation by government bee inspectors following neglect to manage the bees properly and the outbreak of disease.
Many establishments have reluctantly been forced to give up their bees, donating hives away to BKA’s after swarms caste from their hives upset their neighbours. In 2012 two hives had to be relocated from Covent Garden, central London after the bees repeatedly stung bathers at a neighbouring leisure centre with an outside pool.
In 2011 bees from roof top hives at Oxford Circus shut down the cross road junction for hours when they alighted on road traffic lights meaning the bus drivers could not read the signal lights. Mayhem ensued. It took 3 beekeepers many hours to clear up the bees.
Keeping bees in the city centre is a lot of fun and rewarding until they fly into a neighbouring restaurant, scare away their customers and cost the establishment a days’ worth of revenue! This actually happened for real in the summer of 2013 in London’s Piccadilly Circus when 3 times in 10 days a hive on the roof of a commercial property swarmed. Each time the bees descended onto people at ground level costing 1 restaurant a whole days’ worth of takings, a local green grocer £4000 in lost earnings, caused a traffic obstruction and stung several members of the public and police officers attempting to cordon off the area. On each occasion volunteer swarm collectors from the London beekeeping association had to leave their days jobs to attend the scene as the beekeeper being paid to tend to the hives was conveniently not available having a full time job of his own. This is one of my real bug bears about ‘cash for bees’ keepers, they take your money to install and manage hives but are seldom around to deal with the chaos of a high profile swarm in the city centre.In summer 2015 a Netherlands based commercial services company with bees 14 storeys up on a sky scrapper in London’s Canary wharf were the talk of many neighbours after a swarm appeared 200ft above ground level on the adjacent high rise building. Office workers were panicked when they discovered the swarm clinging to their windows and were fearful they may enter the building. Volunteer swarm collectors had to be winched up the side of a building in a safety harness to retrieve the swarm to the amazement of onlookers. The people responsible for managing the Canary Wharf hives claim the swarm did not come from their hives but at 200ft above ground level on the opposite building where else would they have come from?
How high do bees nest naturally?
Legendary honey bee biologist Thomas Seeley who studied honey bees for many decades discovered that Honey bee swarms have a preference for nesting between 3-6 meters off the ground, though they will occasionally nest higher than this as well as occasionally nesting lower down, even at ground level. Honey bees probably prefer to nest several meters above ground because the height affords them a degree of protection from ground based mammalian predators such as badgers and bears. Natural cavities of sufficient size are also more likely to be found in mature trees at these heights. In urban areas we often find feral colonies of honey bees in buildings higher than this, often in air bricks. Bees are adaptable and in man-made environments will nest at higher heights than would normally be found but in the many call outs to remove bees from building cavities I’ve never came across a feral colony any higher than 3 storeys high.
It is not known what the maximum altitude is for honey bees to fly at though they are rarely observed flying higher than 30 meters or 100 feet above ground level. This is most likely due to the fact that bees prefer to avoid strong winds and the higher we go the faster the wind speeds become.
Honey bees are very much a fair weather insect and are reluctant to fly in wind speeds above 15 miles per hour (Morse and Hooper 1985) or force 4 on the Beaufort wind force scale. This is described as a moderate breeze rustling leaves and vegetation, or sufficient to fill the sails on a ship. When this increases to a strong breeze of 21 miles per hour (force 5, Small trees sway, leaves and small branches blow around in gusts) bees really begin to struggle to maintain controlled flight. Flying in stronger winds requires the bees to spend more energy maintaining controlled flight and they will tire more quickly and reach point of fatigue.
Increased wind speed also increases the wind chill, making actual temperatures appear significantly colder, the bees can lose heat and energy more quickly and if they become chilled and inactive they may die. Maintaining metabolic activity outside of the hive in cool conditions again causes the bees to burn more calories and expend more energy. Honey bees seldom fly when temperatures are below 12 degrees Celsius and then they won’t travel very far.
Other repercussions of flying in strong winds include increased instances of drifting with bees alighting at the wrong hive, resulting in fighting at the hive entrance and increased risk of pathogens being spread between colonies. This is one reason why high rise beekeepers in NYC experience poor rates of successful queen mating.
It is well documented that wind speeds increase with height this is termed ‘wind speed gradient.’ For example a ground level wind speed of 21mph (a strong breeze on the Beaufort wind force scale) can increase to 27mph (a strong wind capable of inverting umbrellas) 100 metres above ground level (Bañuelos-Ruedas et al . 2014) . Even on calm days when there is very little to no apparent wind speed at ground level wind speeds 20 metres above ground level could reach 13mph. There are numerous mathematical models for illustrating how wind speed gradients increase with height but the actual wind speeds experienced depends very much on the location and local topography. Physical objects in the landscape including buildings, trees and presence of open water all influence wind speed gradient. In towns and cities rows of tall buildings can channel winds. When strong winds collide with tall buildings strong downward drafts can result, this can make it difficult for bees flying against them trying to return to their high rise hive with heavy loads they have foraged. River valleys are also notoriously windier because the open water of the river offers no resistance to the winds resulting in faster wind speeds and sharper increase in wind speed gradient along river corridors.
The wind speed gradient can have a major impact on hives kept at heights above a couple of storeys reducing the amount of time the bees can experience good flying conditions.
The London Honey company keeps bees on the rooftop of the Tate Modern Gallery on London’s South Bank. They relocate the Tate hives from their modest 5 storey perch each winter to ground level, citing the extreme winds billowing down the Thames valley too troublesome for the overwintering bees. This is a thoughtful act and an example of a company putting the welfare of their bee’s first. Most corporates with hives on tall buildings have nowhere to relocate their hives to ground level in winter when conditions are at their harshest for the bees.
Honey bees prefer natural nest sites with an entrance facing the equator (Seeley 2010). This is because exposure to morning sun aids the honey bees in warming their flight muscles in preparation for leaving the hive and going out to forage. Facing managed hives south or south east benefits the same way as well as preventing prevailing westerly winds from blowing in through the hive entrance. Where possible high rise hives should always be positioned facing south or south east. On roof tops where bees are exposed to increased wind speeds and increased wind chill it is vital that this rule be followed to provide maximum benefit to the colony and protection from the elements. It is also worth checking which direction the prevailing wind comes from (it may not be a direct wind, tall buildings can deflect winds) and siting hives so that they are protected by a wall, chimney or other obstacle to break the wind. Checking the wind speed can be done easily with an inexpensive anemometer which are readily available to buy.
What research has been done on keeping bees at height?
Precious little scientific research has been carried out looking at the effects of keeping bees at great height on tall buildings. In the USA where bees have been kept on tall buildings in many cities for a number of years, there comes a great deal of conflicting anecdotal evidence from different keepers.
In the far north (similar latitudes to London) keepers frequently state that bees don’t do too well above 10-15 storeys, less so in cities on the Atlantic coast or cities located in a river valley or where several river valleys converge such as New York City. Cities away from river valleys and the coast seem to be able to keep bees higher more successfully.
In the Southern States I have met 2 beekeepers who both successfully keep bees in Atlanta Georgia 30 storeys above ground level. The significant difference here is the climate which is significantly hotter and being far inland less influenced by coastal winds.
In NYC for a number of years a small group of beekeepers
have been monitoring hives on tall buildings equipped with an assortment of
remote sensors including hives scales to monitor how the colony gains weight, a
bee counter at the hive entrance which collects data on numbers of foragers
leaving and returning to the hive and temperature sensors. Anemometers have
also been used to record wind speeds at different locations. Thus far only a
small number of hives have been used in this low key study so the results are
not statistically significant but their data gathered does suggest that at
higher heights where wind speed is greater, colonies are less productive, gain
less weight, more foragers leave the hive than return and they have reduced
mating success with their queens.
The researchers believe that colonies higher up experience increased loss of young bees on their first orientation flights. Basically the young bees are weak flyers and are being swept away by the high winds and are unable to find their way home. Increased mortality among young bees orientating then leads to a reduced recruitment to the colonies foraging force. It is also hypothesised that bees at greater heights may live shorter lives as a result of their increased efforts flying in less than favourable conditions. Most of the beekeepers I’ve met in Manhattan have to buy in replacement queens each summer as they struggle to raise their own queens and have them successfully mated in the city. High winds will make it difficult for queens to fly and there is also talk of whether or not the winds and tall buildings are making it difficult for drones to successfully form congregation areas where mating occurs.
These initial findings provide some indication as to the hardships we may be forcing upon our bees by citing them at unnatural heights.
So how high is too high for London?
When we examine the above information and look at London as a city, we can compare it similar cities in the US such as New York or Toronto. Our climate is similar but we have a wetter climate than either of those cities due to the effects of the jet stream which brings moist turbulent weather fronts our way from the Atlantic. London like NYC is in a river valley and along the river in particular wind speeds are greater as they are channelled down the valley. Following the helicopter crash in Vauxhall several years ago there has been increased concern over how the construction of the many proposed new sky scrapers along London’s river corridor will effect wind turbulence to low flying aircraft. These new buildings could also create more turbulent conditions for our bees to fly in.
As a sensible precaution I would think it unwise to site bees more than 4-6 storeys above ground level or not much higher than the tallest mature trees. This is a height which bees would naturally fly at but not necessarily exceed.
Things to bear in mind when citing bees at height
When siting bees at height on our roof tops we must remember that what is convenient for ourselves may not be the most convenient for the bees who we will be forcing to work much harder and as good responsible beekeepers we should always place the bee’s welfare needs before any needs of our own.
Think about the aspect, what features there are to protect
the hive from wind and rain?
Think about the bee’s access to water. Lugging loads of water from ground level to dizzy heights must be hard work for a bee. Give them a water container on the roof top to make life a little easier for them. I use a poultry drinker with small pebbles in the tray so the bees can climb in and out. This works very well as the bees have access to water, the water won’t evaporate quickly in the exposed environment and the bees can’t easily drown in the water vessel.
Some city rooftops have metal roofs, are lined with roofing felt or other dark materials which absorb the heat of the sun and or reflect the suns glare. Thought should be given to protecting hives from overheating and to protecting the bees from being misled into leaving the hive on cool days if the sunlight is reflected by surfaces onto the hive entrance.
Avoid siting hives near vents, windows or air conditioning units – anywhere bees may explore and enter a building or where equipment may produce vibrations or smells which could upset the bees.
Think about how you will manage your hives natural desire to want to swarm. Swarms produced from high rise hives do either 2 things; they cling to the side of a building often in an inaccessible or difficult to access place or they descend towards ground level where they may bother people. Can you inspect the hives every 6-7 days April to August to ensure swarms are avoided? You could clip queens and keep young queens of a strain of bee with a low swarming index which will make managing and avoiding swarms much easier.
At our Nando’s apiary our hives (which are 3 floors up) face South East, have a wall and row of mature trees protecting them from west and northerly winds and the skylight window openings are covered in fine nylon mesh to prevent bees entering the restaurant.
We’ve also planted the roof top with containers filled with spring flowering bulbs rich in pollen. This gives the bees something to forage on close to the hive early in the year when the wind chill may make it a bit more difficult for them to fly than if they were cited at ground level. Every little helps.
As a responsible beekeeper you should ensure your hives are registered with the National Bee Unit and allow when requested access to the roof top apiary by the bee inspectors. If a bee inspector deems your high rise apiary as too precarious for them to access they can make a reasonable request that you move the hives to ground level for the purpose of an inspection.
One thing to be mindful of is how you will dispose of any hives, bees and equipment should your roof top apiary develop a statutory notifiable disease such as Foul Brood. You can't dig a 6 foot hole in the ground on a roof and you cant light a bonfire either! A government bee inspector can order you to euthanise diseased bees, hermetically seal the entire hive and then have you send it for incineration - at great financial cost to yourself. Do you have sufficient insurance to cover such a scenario? This is something I always make people aware of as it is rarely thought about.
I hope this blog post provides food for thought for those thinking about installing bees at height. I don’t want to discourage rooftop beekeeping but it needs to be done correctly and done with the bees welfare needs put before our own desire for honey (or financial gain!).
Morse and Hooper. 1985 The Illustrated Encyclopaedia of Beekeeping. Dutton Publishing
Breeze et all. 2014 Agricultural Policies Exacerbate Honeybee Pollination Service Supply-Demand Mismatches Across Europe. Journal Plos one
Hive Data supplied under freedom of Information request to National Bee Unit 2015
BBKA membership data provided by BBKA 2015
USA hive statistics available from USDA website
Figures for US city hive numbers is based upon personal communications between city BKA chair persons and beekeeping equipment suppliers.
Hadlock, Charles (1998). Mathematical Modeling in the Environment. Washington: Mathematical Association of America
Bañuelos-Ruedas et al . 2014. Methodologies Used in the Extrapolation of Wind Speed Data at Different Heights and Its Impact in the Wind Energy Resource Assessment in a Region. ISBN 978-953-307-483-2
Thomas D Seeley. 2010. Honey Bee Democracy. Princeton Press. ISBN 978-0-691-14721-5
Gouson and Hughes. 2015. Mitigating the anthropogenic spread of bee parasites to protect wild pollinators. Biological Conservation 191, 10–19
Whilst in Atlanta I attended the Metro Atlanta Beekeeping Associations monthly meeting and lecture. I have a few friends there among the association and whenever I come to town I get invited to attend their meetings, meet their members and exchange beekeeping experiences.
Their October guest lecturer was the internationally known Dr Keith Delaplane MBE from University Georgia. See his profile here: http://caes2.caes.uga.edu/bees/personnel/delaplane.html
Before the meeting my friend Cindy, former president of the association introduced me to Keith who has previously worked on bee research projects in the Uk with current colleagues of mine at FERA/DEFRA. We had a brief chat about the work Keith participated in and my colleagues he'd had the pleasure of working with.
As the room packed out with around 50 people attending Dr Delaplane began to gave his talk on his latest research project which has just been funded by the United States Department for Agriculture.
He started off by explaining some of the background of honey bee social evolution and Honey Bee reproductive strategy and how having a single queen devoted to reproduction within the colony brings benefits to the hive. He went on to explain that having highly promiscuous queens which practice polyandry also brings benefits through the diverse genetic make-up of the colony which enables the colony to brave environmental stressors, be more disease resistant and produce more honey.
His latest project will involve the artificial insemination of a large number of queen bees from various stocks. These queens will be inseminated in 3 groups. One group will be given the sperm of just 10 drones, another group the sperm of 30 drones and the last group the semen of 60 drones. The researchers will then compare the colonies performances against varroa resistant hygiene, Productivity, disease etc. Their hypothesis is that instrumentally inseminated queens with a more diverse package of sperm will produce more productive colonies.
At this point he pointed out that the queens receiving sperm from 60 drones will not burst with semen because they are too full! The sperm from multiple drones is blended together then the same amount of the mixture given to each queen. Apparently he’s been asked if queens burst if they are full on several occasions.
Dr Delaplane explained that within each colony there exists sisterhoods made up of workers belonging to the same drone father. These different sisterhoods made up of super sisters often display a preference or exceptional ability at certain tasks within the hives. Some may be better at foraging, others better at producing wax or comb construction, whilst others may be better at brood rearing and others may be more inclined to swarm. Having a diverse workforce means you have more sisterhoods with task specialisms that are well equipped to excel at a wide range of tasks within the colony therefore the colony can survive and thrive easier.
This is the exact opposite of what happens in most bee breeding programs when beekeepers are selecting a small number of drones to inseminate queens as they are looking for a specific set of desired traits. Dr Delaplane believes that rather than selecting for specific traits we should be aiming for queens which have slept around allot and produce a diverse workforce which in itself produces better bees.
He also explained that among the sisterhoods in the hive there are some bloodlines which are royalty and do not make good workers. These bees when they are larva emit a pheromone which screams out to the nurse bees ‘make me a queen’ and in the event the the colony needs to make an emergency queen cell its these larva which are chosen over others as preferential queens because they are genetically programed to be better queens but poorer workers. As workers these bloodlines are basically social parasites and do little to no work in the colony. This was the first I had heard of royal bloodlines in the Honey Bee and had always thought queens were chosen at random or that the bees somehow can tell which larva are fittest and chose them.
It had for a long time been widely hypothesised that sisterhoods would prefer a supersister to raise as the next queen as that super sister queen would share more DNA with her sisters but this has turned out to be one of the biggest scientific flops of the 20th century with over 100 studies failing to prove this is what happens.
So it turns out some queens are born to be queens – but may never become one and others which are not ‘born to be queens’ just happen to get laid in a play cup and become a queen anyway without any particular desire or choice to become one.
Dr Delaplane thinks his new research project could challenge established practices by bee breeders and queen producers forcing them to re-think the trend of selecting a narrow range of desirable traits which produces genetically limited stock.
My own preference for raising new queens is the miller method or I use a special frame inside the parent colony which then snaps apart into several smaller frames fitting into a mini mating hive populated with nurse bees and I leave the bees to decide which of the larva they want to raise into queens. Its less work than grafting and providing you supply the nuc with a frame consisting plenty of eggs or very small newly hatched larva for the bees to choose from they have plenty of time to feed the larva royal jelly and make good queens.
I find that this method works for me better than grafting or using the jenta cup system which I have also experimented with. I get great queens using this method and I think my results coincide with Dr Delaplanes findings thus far.
Late summer for the bees is one of the most desperate times of the year when they can struggle the most to find enough food to eat. Many people find this fact difficult to believe as the weather is often hot and sunny and presumably great for the bees but it is in fact often one of the leanest times for the busy insects. At this time of year colonies are large with many mouths to feed and as the beekeeper has removed the honey crop the flowers are also diminishing in abundance meaning the bees can struggle to replace honey which has been taken off. For this reason it’s crucial not to be over greedy and take all the honey leaving the bees with no stores for themselves.
Come late summer the majority of our nectar rich native wild plants have ceased flowering and gone to seed, especially woodland and meadow flowers whose flowering period is in rhythm with the closing of the woodland canopy and cutting of meadows for hay. Bramble and all our native trees have also long since finished flowering and are now sporting fruits and seeds leaving little for the bees.
Away from Heather moorland and Heaths, the only real bountiful sources of forage from native wild plants are Greater Willow Herb, Thistles, Ragwort, Bindweed and Hogweed – though many of these are early this year and already going over. Along water courses Purple Loosestrife, Marsh Woundwort, Water Mint and the invasive Himalayan Balsam provide welcome relief but not everyone is in range of such localised sources of forage.
Early summer, June in particular is a time of the year which brings uncertainty for many a beekeeper, and for those in rural areas in particular. June is the beginning of the summer season when the spring flowering plants and trees shed their blooms having been pollinated and now begin to form seeds but the main flow of summer flowering blooms has yet to begin. Beekeepers refer to this period of change as the June Gap.
At this time of year Honey bee colonies are approaching their peak in worker population in readiness for the summer flow, Queens are laying at a prolific rate and colonies have many larva to feed. A reduction in incoming nectar and pollen as the spring flowers cease but the summer flowers are yet to peak can leave large colonies struggling to feed themselves or fill supers with surplus honey for the beekeeper.
Following a very mild
March the forage this season appears to be well advanced of recent springs,
even in comparison to last year’s very mild winter and warm start to the year.
2017 has started cold and chilly but in late March this has warmed up considerably.
So much so that I experienced my first attempt at a swarm during the last week
of March and already the new queens have emerged and unbelievably appear to
have been mated and are laying in the first week of April!!!
During the first week of April many of our true heralds of spring had already begun to flower across the city. Cherry Laurel Prunus laurocerasus an evergreen shrub who’s flowers are a useful source of spring forage have been out in bloom since mid-March 2-3 weeks earlier than last year. Whilst manning the LBKA stall at Ascot race course on the 2nd April I saw many Andrena Mining bees, Honey bees, Bumble bees, Hoverflies, Queen wasps and Queen Hornet nectaring on the blooms of these tall shrubs growing around the car park.
Damson, Plum, Gage, and other stone fruits have largely flowered and gone over already as have crocus, daffodils and snow drops. My flowering currant normally just blooming now is almost over already meanwhile Blue Bells are coming into flower.
Blue bells may be visited by Honey bees and can produce a honey crop but they are also popular with some of the longer tongued solitary bees and Garden Bumble Bee Bombus hortorum . Most of the Blue Bells found growing in our gardens and sadly in many of our wilder places are the larger invasive Spanish Blue Bell Hycinthoides hispanica and not the native English Blue Bell Hycinthoides non-scripta . You can tell the two species apart by the way that the individual bells hang on the flower stalk. In English Blue bell the bells all hang on the same side but in the Spanish Blue Bell they hang at different angles all around the stalk. They also have green to blue pollen whilst English Blue Bells have a creamy coloured Pollen. Blue Bells frequently hybridise and these offspring can be difficult to differentiate.
March is officially the first month of spring for us in the UK, though in London it has felt spring like for several weeks now.
Already the first of the spring flowers are putting on a colourful show of yellows, purples and shades of white. Snow drops are starting to go past their best having flowered in numbers since Late January. The early flowering species crocuses are currently looking at their best across most of London and the later flowering large flowered Crocus varieties are just starting to join the display too.
These and other spring bulbous plants including Winter Aconite, Anenemone blanda, Squill and Muscari are valuable early sources of pollen for bees.
2017 has started off quite differently from last year’s exceptionally warm January. Last year in the first week of January I participated in the Botanical Society of Britain and Ireland’s annual New Year’s plant hunt and found 76 species of plant in bloom during an 8 mile walk around East London. In contrast on the 3rd of January this year I found just 9!
January 2017 has seen a return of the more usual cold winter temperatures and from what I can tell so far the return towards more normal timings of the seasons and emergence of spring plants and animals. The recent cold weather has meant that late season flowering plants have ceased blooming before Christmas and not persisted through winter as they did last year meanwhile spring flowers have remained doorman and not yet begun to emerge.
Despite the weather being generally cold with some particularly harsh ground frosts there have been occasional mild days when the bees will fly to cleanse their bowels and look for food. Despite the cold there are a select few flowers in bloom which they can take advantage of.
Few native plants are yet in bloom but several exotics flourish in late winter through to early spring providing a bounty of forage for the few insects brave enough to venture out and take advantage of them.
Mahonia or Oregon Grape grows in our towns and cities in abundance and flowers throughout the winter providing nectar and pollen for bees. In southern towns and cities Buff Tailed Bumble Bees Bombus terrestris are increasingly continue to be active throughout the winter surviving largely on this plant. Around 75% of winter flower visitations by bees are to Mahonia. The variety ‘winters sun’ is particularly attractive. Bees taking advantage of Mahonia blooms in winter have few other insects to compete with and can fair better than some colonies active in summer. On the 12th December I discovered an active Buff Tailed nest in west London beneath a Pyracantha hedge. I’ve been monitoring it all winter and whenever there is a warm day the workers can be seen busily coming and going from a large stand of Mahonia shrubs across the street from the nest. The blooms will only last a few more weeks so hopefully an equally good source of forage will come into bloom nearby to ensure the colony has sufficient forage coming in to enable it to produce new queens and drones by spring when the nest dies off.
Viburnum shrubs include a number of deciduous and evergreen species which flower during the winter months. They are relatives of our native Guelder Rose Viburnum opolus . Some of the most popular Viburnums with our bees include the evergreen Viburnum tinus who’s sweetly scented cream blooms flower from November through to March and Viburnum bodnaatense whos pink flowers bloom from around Christmas to March.
Winter Heliotrope Petasites fragrans is a relative of our native Butterbur but flowers much earlier. Its not a UK native and can be quite invasive when established in the wild but is a great garden plant for bees in late winter. The flowers are shaped like a toilet brush and pink in colour.
Clematis . Several Clematis species are useful forage sources to bees in winter. Clematis amandii and Clematis cirhossa both have creamy white flowers and bloom in winter. Honey and winter active bumble bees will visit them for pollen.
Hellebores include the familiar ‘winter rose’ with its large white blooms ‘ orientalis ’ and its many cultivated hybrids and the native Stinking Hellebore helleborus foetidus .
Winter Flowering Cherry Prunus subhirtella flower from late November to February producing pale pink flowers. I’ve very rarely seen any bees on the blooms but have often seen flies on them. In the absence of better forage like Mahonia bees will visit the flowers.
Sweet Box Sarcococca confusa is a short growing evergreen shrub which produces extremely fragrant blooms (reminiscent of hyacinths) from late winter into early spring. It’s one of those plants that you almost always smell long before you see it.
Winter Heather/Heaths Erica species produce tubular blooms in shades of white to pink throughout the winter. They are coming to the end of their flowering period now but still providing forage for bees brave enough to venture out.
Winter flowering Honeysuckle . Several Honeysuckles flower during winter. Some are climbers other are shrub forming. One of the best is Lonicera fragrantissimima .
As we progress beyond February into March the usual array of spring blooms will begin to appear. Their arrival is not far off, already a few brave Daffodils, Snow Drops and Winter Aconite have made an appearance. They will be joined by Crocus, Muscari, Sweet Violets, White Deadnettle and Pulmonaria.
Firstly lets start with wasps Beekeepers in America like those the world over have a hateful relationship with wasps. Here in the UK we have about half a dozen species of wasp which can pose problems for our bee colonies. These are mostly social wasps which build paper nests but there is also one solitary wasp – the Bee Wolf Philanthus – which hunts almost exclusively on honey bee workers which it buries underground and lays its eggs on after paralysing the bee. Most of these wasps are little more than a nuisance, few can actually cause any real damage, and when they do it is usually already weak colonies which are effected. Reducing hive entrances to make the colony easier for the guard bees to defend is usually all the intervention needed. In the US they have a whole different range of native wasps which predate bees as well as common Wasp, German Wasp, Tree Wasp and European Hornets which have been accidentally introduced from Europe. In total they have around 20 species of social wasps which all, to some degree prey, on honey bee colonies.
Honey Bees are not native to North America so have few defences against the native wasps which must have delighted at their arrival in the 1600s. Among the most common social wasps which can cause problems for US beekeepers are the Yellow Jackets. These are very similar to European common wasps which are the scourge of picnic tables in late summer and sometimes rob our honey bees. Yellow Jackets almost always nest underground among thick undergrowth. In 2013, I was the victim of a vicious Yellow Jacket colony which went on the rampage after an innocent bystander accidentally stepped on their nest during an event in Piedmont Park in Atlanta. 100s of wasps came pouring out of a small hole in the ground – probably an old mouse burrow and flew straight up my shorts stinging my groin. My friends were stung on the face, arms and legs. The stings were extremely painful and burned intensely. They were far more painful than any bee sting and I would not want to experience it again. There are several species of Yellow Jacket which all look very similar. They are the Eastern Yellow Jacket, Western Yellow Jacket, Prairie Yellow Jacket and the Southern Yellow Jacket. All the Yellow Jackets are in the genus Vespa which is the same Genus that our common wasps and European Hornets belong to.
By now the vast majority of the UK’s 277 species of bee are well tucked away for winter. The majority of our bees are solitary and the most of these bees die in late summer leaving behind their offspring entombed deep inside underground burrows or imprisoned inside hollow plant stems or decaying wood. These bees will either overwinter as a pupae, pre-pupae or as a fully mature bee but they will not vacate their birth site until spring.
Bumble bees colonies die out in autumn and only the queens survive winter by hibernating. In autumn the queens feast on pollen and nectar to fatten up for their long sleep.
In the south of
the UK, particularly in towns and cities some of these bumble bees may remain
active all year round. The Buff Tailed Bumble Bee is our most winter hardy bee, they are large and furry, can
regulate their own body temperature and regularly fly on cold days when other
bees are nowhere to be seen. They will even fly in snow.
In southern towns and cities Buff Tailed Bumble Bees are increasingly starting to found new colonies in late autumn rather than going into hibernation. The abundance of exotic winter flowering shrubs in urban areas and lack of competition from other pollinators means these bees can thrive during the winter months. Mahonia is particularly important to winter active bumble bees, 75% of flower visitations by bees in winter are to this plant alone. There are numerous varieties of Mahonia but my favourite is ‘Winter Sun’ which is popular with the bees.
The Christmas Wreath
Christmas wreaths predate Christmas and Christianity by several thousand years. Originally ancient Britain’s and other northern Europeans would have made loose hanging wreaths (basically just a bundle of greenery tied at the top and hung from the walls of their home) as a means to warn off winter spirits. It is only later with the rise of the Christian churches that Wreaths adopted a circular shape mirroring the crown of Christ. Our ancestors believed that evergreen plants were magical because unlike other plants they didn’t die back and shed their leaves in winter. Additionally many evergreen plants like Holly produce long lasting berries which were a symbol of life and fertility. Plants like Ivy who’s berries persist long into winter as well as being evergreen climb and entwine representing matrimony and togetherness. Strongly scented sprigs of conifer would have hidden the foul odours of winter (no fridges back then so perishable foods would not last long even when dried and salted and would produce a pungent smell)
Key items used in wreaths include Holly Ilex aquifolium which is pollinated by Honey bees and Andrena mining bees who’s short tongues are well equipped to manipulate the strongly scented but visually insignificant flowers. Ivy flowers are pollinated by a wide variety of insects and are a valued autumn forage source but has its own special pollinator the Ivy Mining Bee Colletes hedera which only collects pollen from Ivy and times its emergence to the opening of the Ivy flowers.
One of the things I have been very interested in during my travels throughout the United States was investigating how different urban areas compare to London in terms of forage availability. To begin my comparison we first need to understand what we have here at home in London.
Here in London we have very high hive densities in some parts of the city. According to 2016 figures from the National bee Unit Greater London has around 5000 hives and around 1400 beekeepers. The exact number is unknown as it is estimated that 25-30% of beekeepers do not register. With this in mind the actual number of managed hives in Greater London could be as high as 6200. NBU data also shows that in some central London areas hive density is as high as 13 hives per square kilometre – greater than many rural areas. Unlike many rural areas which have vast swathes of agricultural crops which provide a limited variety but seasonal super-abundance of nectar, London has less abundance of forage but a greater variety due to the wide range of exotic plants grown in the city’s parks and gardens. What this means for bees and beekeepers in London is that our bees have a much more balanced and varied diet offering them a wider range of nutrition but our honey crops generally fall 30% short of the UK national average. According to the BBKA honey survey results for the past decade London has consistently been the lowest yielding region in the country in terms of average volumes of honey produced. The exception to this trend has been 2015 and 2016 when national averages plummeted due to the cold, wet and windy spring weather but London yields remained the same (due to our microclimate and more stable weather patterns)
London is 61 percent green space by land area. Of this 14% is domestic garden green space, 38.4% is public green space and the remaining is made up of commercial green space, railway sidings, brownfield land and green roofs according to data from Green Space Information for Greater London (GIGL), The General London Assembly (GLA) and the 2012 World Culture report.
London also has an abundance of trees with tree canopy covering 21.87% of the city. In 2003 London had around 7 million trees – almost as many trees as there are people and there are targets to increase this by 5% by 2025. Under the Mayors RE:LEAF initiative 75’000 new trees are planted in the City each year. On the surface London is a pretty green city but when we look more closely at the available data we begin to see that some parts of the city’s green areas are little more than green deserts. According to Kew Gardens around half of London’s half a million street trees are sterile London plane trees, as are many of the trees in central London parks. These sterile hybrids offer no pollen or nectar for pollinators and much of our parks these trees grow in are also largely short cut grass with few flowers for bees. Increasingly urban planners are planting birch and alter trees because they grow rapidly, take up little space and are low maintenance and tolerate the poor, dry urban soils. These trees offer no pollen or nectar for bees.
Generally speaking the green spaces closer to the city centre tend to offer less foraging opportunities than those further out which are often more wild and rugged and contain more wild flowers. Further out we have more large habitats including heaths and commons which are less intensively managed. Also further out into the London suburbs more of our railways are above ground and lined by thickets of Bramble, avenues of trees and more of the road verges include green buffers. There are exceptions, the gardens at Buckingham palace for example are known to have a rich diversity of flowering trees including wilder areas. For some time there has been a growing concern that in some areas of the city we may have reached saturation point where numbers of hives has reached the limits of what local forage can support. It is this concern which is leading many organisations including LBKA to promote the planting of flowers and trees for bees. There are now a number of initiatives such as river of flowers and bee lines project which aim to create landscape scale bee friendly corridors of suitable flower habitat through parts of the city to link up pollinator populations and help provide forage for bees. On the whole though London is a good place for bees, and is by no means a bad habitat for bees but as I discovered on my travels there is much room for improvement and some of the US cities I visited put us to shame when it comes to providing habitats for pollinators.