Category: bees

Walking among bees with Steven Falk

Posted on by andy.winfield

By Nicola Temple

Steven speaking to us in front of the limestone
meadow. Photo: Nicola Temple
I thoroughly love watching insects visit my garden (aphids and a few other pests excepted). However, I have to admit that beyond broad groupings, bumblebee, honey bee, hover fly, fly etc, I’m not very good at identifying them down to species. This clearly isn’t necessary to enjoy them, but I do find that when I know a species, when I know its routines and habits (as much as anyone does), then I have a deeper appreciation for them. So, when the University of Bristol Botanic Garden offered a bee identification workshop with Steven Falk, I signed myself up.
Steven Falkhas had an interest in insects since his childhood in London in the 1960s and 70s. Insects inspired his artwork and his skill as an artist earned him the honour of illustrating the book British Hoverflies, which he began working on when he was only 15. He has gone on to illustrate and write many publications since, including my newly acquired Field Guide to the Bees of Great Britain and Ireland (Bloomsbury, 2015).
Steven began the talk with some fast facts about insects in England. There are about 24,000 species of insect in England, 6,000 of which are regular visitors to flowers. “The biggest slice of this insect pie is wasps,” he explained. Even parasitic wasps visit flowers, and all together there are around 2,800 species.  Bees make up a mere 280 species and hover flies another 280. However, though they are less diverse in terms of species, bees and hoverflies are both abundant and extremely effective pollinators – so they punch above their diversity, so to speak.
Steven holding a yellow-legged mining-bee.
Photo: Nicola Temple
We start our walk in the Botanic Garden in the limestone meadow, just beside the West Terrace and the pond. If you unfocus your eyes a little and stare across the flowers, it is alive with activity. Steven shows us Myathropa florea, a reasonably sized hoverfly that has distinct grey markings on its thorax. It has an aqueous larvae, which lives in little rot holes at the base of trees. Then Steven points out a bumblebee mimic, Cheilosia illustrata, which tends to spend time near Hogweed because its larvae tunnel through the stems and roots. Apparently you can tell the age of a forest by the species of hoverfly present because they are so closely associated with certain plants.
Within minutes we’ve also spotted a common carder-bee (Bombus pascuorum) with its chestnut thorax – though Steven explains that this can be quite variable. It has a longer tongue and so this species is able to get down into the clover flowers. But there are also some buff-tailed bumblebees (Bombus terrestris) flying about also, which have shorter tongues and so they bite a hole at the base of the flower to rob the nectar. We spot lots of honey bees (Apis mellifera), which Steven also explains can be extremely variable in appearance, ranging from the typical striped appearance to almost entirely black – the tell tale sign being that its hind legs hang down as it flies. We haven’t even moved on the tour and we’ve already spotted at least six pollinator species – probably far more, I just can’t write fast enough to keep up with Steven listing them off!
The ‘fuzz’ of lamb’s ear is used by the female
wool-carder bee to line her nest.
Photo: Nicola Temple
Using what he calls his ‘praying mantis’ technique, Steven grabs a yellow-legged mining-bee (Andrena flavipes), and holds it so that we can all have a look at it. The long antennae tell you that this is not a fly, however, Steven goes on to list the colour variations that you can encounter. With all of these colour variations, I’m pretty sure I don’t stand a chance of accurately identifying anything on my own!
As we wander past some Lamb’s ear (Stachys byzantina), Steven mentions that the female wool-carder bee (Anthidium manicatum), a solitary bee, uses the fuzz from the plant’s leaves to line its nest. Steven then spots a patchwork leaf-cutter bee (Megachile centuncularis) and explains that it doesn’t collect pollen on its hind legs, but rather on its underbelly. Using his insect net, he catches it and place it temporarily in a little tube so that we all get a chance to look at it.
We walk past the wall germander (Teucrium chamaedrys) and there doesn’t appear to be a single flower that isn’t being visited by a bumblebee. It becomes obvious that while many of the tour participants are interested in the bees, they are equally interested in noting down which of the plants in the Botanic Garden are popular with pollinators so that they can create more bee-friendly gardens at home.
A great pied hoverfly (Volucella
pellucens).
Photo: Nicola Temple
As one would expect, near the end of the tour Steven begins to discuss some of the challenges that our pollinators face these days. He discusses the use of pesticides and the loss of habitat. He mentions that more erratic weather patterns and mild winters can lead to mortality – the latter causing over-wintering bees to go mouldy. But, he also finds the silver lining, stating that some bee species are expanding their distribution due to climate change.
It was only the commitment to another tour that forced Steven to end our walk. His love and enthusiasm for insects was apparent and he could have no doubt gone on to discuss far more than he did.
I definitely had different expectations for the workshop. I’m not sure whether it was the term ‘workshop’ or my own background in biological sciences that set my expectations that we would be looking at example specimens and comparing their features so that we might be able to better identify them. This was more of a garden tour and pollinator walk, which was lovely, but I’m not entirely sure I feel better equipped to identify bees in my garden as a result of being on the tour. If anything, it has shown me how much variation there can be within species let along adding in mimics and related species into the mix!  In the end I bought the Field Guide because really, in the end, that’s what it takes…good ol’ practice! And if I’m unsure Steven said to send him a picture on Twitter and he’ll help me identify it, which is brilliant! Not to mention, he has a fantastic free site on Flickr with pictures and information about all the British species, which is an incredible resource.
Germander (Teucrium chamaedrys) attracts
a tremendous number of pollinators.
Photo: Nicola Temple
This is the Year of the Pollinator at the Botanic Garden, so there are any number of pollination themed activities happening this year, including a beekeeping taster day, short courses for encouraging pollinators to your garden, and of course the annual bee and pollination festival in September.  And if you happen to snap a great photo of a pollinator this summer, you can enter the Botanic Garden’s photography competition, which will earn you a signed copy of Steven’s Field Guide to the Bees of Great Britain and Ireland as well as tickets to the Bee and Pollination Festival, visit the website for more details on how to enter.

Bumblebees who brave the winter

Posted on by andy.winfield

By Nicola Temple

This past weekend, my family and I met with friends in the village of Shipham, in Somerset, for a walk. It was torrential rain, yet we were determined. We dressed ourselves and three children under the age of 10 in waterproofs and set out. We arrived at a local country pub, not more than 3 km away, resembling drowned rats. And as a Canadian living here in the UK, I still marvel at the fact that nobody took one bit of notice at the state of us. It’s what you do. You get wet. You find a pub. You hunker down for a hot Sunday lunch. And you hope it tapers off before you have to head out again. (It didn’t.)

Pollinators, at least of the flying insect variety, aren’t terribly keen on this kind of weather either. Most hunker down for the winter months as there is generally not a lot of nectar to forage this time of year anyway. How they do this depends on the species. Honeybees reduce the colony to a minimal size and rely on their honey stores to see them through, while they dance in order to regulate the temperature of the hive. Most bumblebee colonies die out completely and the queens that mated at the end of the season find a place to hibernate. Solitary bees may hibernate as adults or as larvae, emerging only when the weather conditions are suitable. To each their own.

Martin Cooper spotted this buff-tailed bumblebee queen
foraging on his Mahonia flowers in Ipswich on a sunny
January day in 2015.
Photo credit: Martin Cooper [via Flickr CC]

However, there is one flying pollinator that can be spotted this time of year here in Bristol, and indeed, other warmer regions of the UK. It is the common buff-tailed bumblebee (Bombus terrestris). This species was first spotted during the winter of 1990, in Exeter. Sightings have been increasing ever since and include nest-founding queens, workers and males, suggesting this is a winter generation of the species.

The mated queen will emerge from her subterranean dormant state (diapause) during warm winter weather and set about establishing a new colony. The potential cost of waking up early is that the warm weather could be short-lived and temperatures could plummet. The benefit, of course, is that there’s nobody to compete with for food. If successful, the queen can establish a colony before the other pollinators even wake up from their winter nap.

Introduced plants provide winter forage

Of course, there is potentially another cost to emerging early – there could be nothing to eat. Bees are able to forage at temperatures around 0oC, but if there aren’t enough plants in flower, they won’t find the pollen and nectar needed to sustain the colony. Few native UK species flower in winter, but species introduced by avid gardeners to bring some winter colour to the garden, also bring some much-needed food to the buff-tailed bumblebee.

Researchers at Queen Mary University of London and The London Natural History Society, conducted a study of buff-tailed bumblebees foraging in London parks and gardens during winter about ten years ago. They wanted to see just how much food the bees were finding as food is directly related to the success of the colony.

The researchers found that there was plenty of forage to sustain the colonies and, in fact, the foraging rates they recorded near the end of winter were equivalent to peak foraging rates found in the height of summer. This doesn’t mean that the winter-flowering plants, such as the evergreen shrubs of the Mahonia spp., are providing more pollen and nectar than all the plants in the height of summer. But it does mean that each flower might have more pollen and nectar available because there aren’t other pollinators out and about also using the resource. The bumblebees, therefore, don’t need to go as far to find an equivalent amount of food and so they can collect it at a faster rate.  

Strategies for tolerating cold

Buff-tailed bumblebees aren’t as tolerant to cold as some other bee species; workers will freeze solid at about -7.1oC while queens freeze at -7.4oC. The bumblebees can obviously find warmth in the colony, but they need to forage and therefore be able to tolerate short spells of cold during the winter months. They may even need to tolerate cold temperatures for up to 24 hours as bumblebees often overnight away from the colony when they are unable to return from foraging.

Researchers from the University of Birmingham looked at the different cold tolerances of this bumblebee species a few years ago. They found that 50% of workers died after being exposed to 0oC for 7.2 days while queens could last over 25 days at this temperature – likely due to their fat reserves. However, as the forage study showed, the bees seem capable of finding food sources closer to the colony during winter months, which may reduce the likelihood of them having to endure cold temperatures for a lethal period of time.

These bumblebees may also have adopted some strategies to help reduce their possibilities of freezing. Pollen is an ice-nucleating agent in that it promotes the development of ice at higher temperatures. Other insects have been observed to expel any ice-nucleating agents from their gut when they experience low temperatures to avoid freezing. While this wasn’t observed in the bumblebees, it is a strategy that individuals might employ when caught out in the cold.

The more frequent observation of buff-tailed bumblebees in winter is thought to be a result of warmer autumn temperatures brought about by climate change. In a study from 1969, researchers reported a 6-9 month dormancy of all bumblebees in southern UK, so in a relatively short period of time there has been a considerable change in their seasonal pattern. There seems to be some flexibility in these patterns among bumblebees and for now, establishing winter colonies seems to be working for the buff-tails. However, with so many of our pollinators under threat, there is obviously also concern among the scientific community that more frequent extreme weather events could also spell disaster for these colonies that have selected to brave the winter months. As gardeners, we can perhaps do our bit by planting some winter forage species.

This year, the University of Bristol Botanic Garden will embrace a pollinator theme, with the aim of highlighting some of the lesser-known pollinators that are so important here in the UK. We love our pollinators, but research is still revealing so much about their unique and complex relationships with plants. So watch this space as we share some of these wonderful stories through our blog. We will also be posting pictures of pollinators we see in the Botanic Garden on our Twitter feed and Facebook page. But to see these pollinators in action, take some time to visit the Botanic Garden. Make space in your busy schedule to watch nature at its best – it’s worth it.

Sources:

Alford DV (1969) A study of the hibernation of bumblebees (Hymenoptera: Bombidae) in Southern England. Journal of 
     Animal Ecology 38: 149-170.
Owen EL, Bale JS, Hayward SAL (2013) Can winter-active bumblebees survive the cold? Assessing the cold tolerance of 
     Bombus terrestris audax and the effects of pollen feeding. PLoS ONE 8(11): e80061.          
     doi:10.1371/journal.pone.0080061
Stelzer RJ, Chitka L, Carlton M, Ings TC (2010) Winter active bumblebees (Bombus terrestris) achieve high foraging 
     rates in urban Britain. PLoS ONE 5(3): e9559. doi: 10.1371/journal.pone.0009559 

Bristol is buzzing, how the city is helping pollinators

Posted on by andy.winfield

By Helen Roberts

There has been a substantial amount of press coverage recently on the plight of our pollinators. They are now less abundant and widespread than they were in the 1950s. A number of threats are responsible, including habitat loss, disease, extreme weather, climate change and pesticide use.
A swathe of flowers for pollinators bring a
lot of cheeriness on a grey autumn day on
Horfield Common, Bristol.
Photo credit: Nicola Temple
There is not one smoking gun among these threats, but rather the combination that has endangered some species in the UK. Loss of wild flower rich habitat (due to intensive agriculture, industrialisation and urbanisation) escalates the effect of disease, extreme weather, climate change and pesticide use. Without food or shelter, pollinators are more vulnerable.

 Whilst visiting the University of Bristol Botanic Garden this autumn, I noticed the abundance of pollinators busily visiting many different flowers from the orchid look-a-like flower of Impatiens tinctoria to the swathes of Rudbeckia sp. and Verbena bonariensis. This year saw the 6th year of the University of Bristol Botanic Garden hosting the Bee and Pollination Festival in September. The Community Ecology Group from Bristol’s School of Biological Sciences was exhibiting and promoting their research as well as the exciting Get Bristol Buzzing initiative.
To find out more about pollinator research at the University, I met up with Dr Katherine Baldock, a Natural Environment Research Council Knowledge Exchange Fellow from the School of Biological Sciences and the Cabot Institute, to discuss the group’s work.
“Most people know that pollinators are important, but quite often don’t know what to do to help them, “ explained Katherine. “And this is where our research at the University comes into play”.
The aim of Katherine’s fellowship is to improve the value of the UK’s urban areas for pollinators by working with various stakeholders, such as city councils, conservation practitioners and the landscape industry. 

Translating science into solutions

NERC KE Fellow Dr Katherine Baldock.
Photo credit: Nicola Temple.

Up until 2014, Katherine worked on the Urban PollinatorsProject, which is researching insect pollinators and the plants they forage on in urban habitats.
Building upon research from this project and her current Fellowship, Katherine and her Bristol colleagues have contributed to the development of  a Greater Bristol Pollinator Strategy(2015-2020). The University research group has teamed up with Bristol CityCouncil, the Avon Wildlife Trust, Friends of the Earth Bristol, Buglife, SouthGloucestershire Council and the University of the West of England to implement this with the aim of protecting existing habitat and increasing pollinator habitat in the Greater Bristol area.
The group is also raising awareness of the importance of pollinators to a wide-ranging audience within the city and further afield. This is the first local pollinator strategy within the UK and follows closely in the wake of the Department for Environment, Food and Rural Affairs’ National Pollinator Strategy launched in 2014. It will help to promote aspects of the national strategy relevant to urban areas and hopefully set a precedent for the development of other local pollinator strategies throughout the UK.
The local pollinator strategy outlines actions that will help fulfill the strategy aims, including:
·         formation of a Local Pollinator Forum intended to share knowledge and best practice,
·         establishment of a joined-up approach to pollinator conservation by linking projects through the Get Bristol Buzzing initiative,
·         working with the public in local areas to explain actions they can take as individuals.
“Urban green spaces are important corridors for wildlife and help to provide linkages across the country”, explained Katherine. I envisaged a series of insect aerial motorways linking the whole of the UK, invisible threads connecting countryside, urban fringe and city centres.

The bee link-up

The Get Bristol Buzzing initiative is doing just that, as one of its strategic aims with the local pollinator strategy for 2016-2020, is to “Map pollinator habitat and identify target sites that allow habitat networks and stepping stones to be created to enable pollinators to move through urban areas”.
Katherine talked about how engaging the public at ground level was really important to Get Bristol Buzzing. The initiative is the pollinator component of My Wild City, a project whose vision is for people in Bristol to help transform spaces into a city-wide nature reserve. A number of interactive maps have been created that allow people to add what they have been doing in their area to help wildlife. The Get Buzzing initiative will feed into these maps.
Kath said, “The fact that you can add yourselves onto a map makes the Get Buzzing Initiative really visually appealing to people and much more personal.”

So, what can you do at home to help urban pollinators?

·         Plant for pollinators. Think about what plants you have in your garden. Could you change the planting or improve on it to make it more attractive to pollinators? Think about growing species that have nectar and pollen rich flowers and let your lawn grow longer to allow plants to flower.
·         Avoid pesticides. Most gardeners like their plants to remain pest free but avoid the temptation to use pesticides and accept the fact that you will lose some plants to pests. Instead try to encourage wildlife that will devour those pests or cultivate plants that will deter pests. 
·         Provide habitat. As pollinators need a home, you can always make your own nest boxes if you want to give your pollinating visitors a helping hand by drilling holes in a log or by bundling up lengths of hollow sticks such as bamboo. Visit the Botanic Garden’s bee hotel for inspiration!
“Setting aside a wild bit of garden can help pollinators by providing food, but provides nesting sites too”, remarked Katherine.

Additional information:

·         The Urban Pollinators Project was recently listed as one of the top 10 ground-breaking research projects in the Daily Telegraph. Read more.

·         Results from this research have recently been published in the Proceedings of the Royal Society B with more publications in press. A list of publications can be found here.

·         You can read more about Dr Katherine Baldock and the Urban Pollinators Project on page 7 of the 2015 edition of the Cabot Institute’s magazine.

The science of nectar

Posted on by andy.winfield
Nectar is that sweet reward that flowering plants provide animals in exchange for their services as pollinators. It sounds incredibly simple on one level – much like rewarding a dog with a treat after it obeys a command. However, dig a little deeper and you realise that the reproductive success of the plant is dependent on very subtle yet complex characteristics of this substance – including when it’s produced and how much is produced, as well as its very composition.
Flowering plants will optimise the characteristics of their nectar in order to influence the foraging behaviours of pollinators and ultimately improve their reproductive fitness. The characteristics of the nectar not only determine which pollinators are attracted and when they come, but how frequently they visit and how long they stay. Suddenly one realises that there is an extremely complex system of regulatory mechanisms behind nectar secretion, which have not only influenced the evolution of flowering plants, but of the pollinators themselves.
Red admiral butterfly close up
Red Admiral butterfly (Vanessa atalanta) drinking nectar. 
Photo credit: Shelby Temple.

Nectar isn’t just about sugar

But before we get into the evolution, let’s first consider what nectar is, because as it turns out it’s not just about sugar – there are a number of things in nectar that are important for pollinators.
There is no denying, however, that carbohydrates – sugars such as glucose, sucrose and fructose – are usually the main constituent of nectar. Nectar will be anywhere between 7 to 70 % carbohydrates per water weight [1]. Other sugars might also be present in small amounts as well as sugar alcohols, such as sorbitol. It is these sugars that are the primary energy source for nectar consumers.
Amino acids and proteins are the next most abundant solute in nectar after the sugars. There are essential and non-essential amino acids, which are the building blocks for proteins and there are some non-protein amino acids that are constituents of enzymes and preservatives. It is thought that the amino acid and protein content of nectar may play a role in the taste preferences of insects [1], presumably related to their nutritional needs.
The water content of nectar may also be an important reward for pollinators, particularly in dry habitats.
Nectar also contains important ions, such as potassium, as well as antioxidants, trace amounts of lipids and some secondary compounds that seem to be associated with resistance to herbivory. 
Macro photography bee
A bee gathering its nectar reward in the Botanic Garden.
Photo credit: Shelby Temple.
Many species have also been shown to have antimicrobial compounds in their nectar, which prevents microbes from growing in the nectar as well as inhibiting florally transmitted diseases [2].
Terpinoids, which are the volatile organic compounds that give flowers their scent, also accumulate in the nectar.
The composition and consistency of nectar is extremely variable as it is tuned to the needs of the nectarivores (it’s a word…really). Flowers frequented by hummingbirds, for example, generally produce nectar in small amounts with high sugar content, while those frequented by more generalist passerine birds produce dilute nectar in large quantities. There has been some evidence that honeybees have a preference for warmer nectar that’s less viscous, regardless of the sugar concentration [3]. Bats also seem to prefer less viscous nectar, though will preferentially select more dilute nectar as the water content is extremely important for their rehydration.

Not all nectar is produced in the flower

Nectar is produced in glands known as nectaries. The glands are commonly found at the base of flowers, where they produce nectar as a reward for pollinators. However, there are also extrafloral nectaries located elsewhere on the plant, often on the leaves or petiole – the stalk that attaches the leaf blade to the stem. These nectaries provide a reward for mutualistic animals, almost exclusively ants, which benefit the plant. The ants help protect certain plant species by getting rid of the eggs of herbivorous insects deposited on the foliage and in return they feast on the nutrient rich nectar secreted by the extrafloral nectaries.
Extrafloral nectaries might be particularly critical at certain times in the plant’s lifecycle. For example, there are often nectaries located on the pedicelthat secrete nectar when the flowers are in bud. This attracts ants, which help protect the vulnerable flower buds from herbivorous insects and improves the reproductive success of the plant [4].
Unlike nectar produced in the flower, nectar produced in the extrafloral nectaries is far less variable as it is attracting mostly ants.

Darwin’s orchid: a classic example of the coevolution of flowering plants and their pollinators

Producing nectar may use up to 37% of a plant’s available energy [5]. This means that producing it comes with some cost to the plant, but these costs are clearly outweighed by the benefits of attracting pollinators that are far more efficient than relying on wind or water.
The evolution of flowering plants and their pollinators is the most frequently used example of coevolution – the physical characteristics of both flower and animal evolving to become more specialised. It was around 120 million years ago that honeybees developed longer tongues than their short-tongued ancestors in order to access the nectar reward flowers had started to produce. Their social structure became more complex and they became fuzzier and developed pollen baskets in order to carry protein-rich pollen, but also facilitating their role as pollinators.
Darwin’s orchid in bloom at the Botanic
Garden last year. Photo credit: Andy Winfield.
The flowers also changed shape in response to the preferences of their pollinators. The most classic of these examples is Darwin’s orchid (Angraecum sesquipedale) with a flower depth of 20 to 35 centimetres. The Madagascar orchid was named after Darwin because he proposed, based on its shape alone, that it had to be pollinated by an insect with a proboscis of lengths unheard of at the time. Forty years later, Morgan’s sphinx moth (Xanthopan morganii), was discovered with an unusually large proboscis…and it was indeed the pollinator of this orchid.
It is also thought that nectar chemistry itself has evolved in response to pollinators. As mentioned earlier, bats prefer nectar with low sugar concentrations and as a result bat pollinated plants from very diverse and distantly related taxonomic groups have evolved nectar with low sugar concentrations.

Deceit and robbing

Not all flowers use nectar – some have non-rewarding flowers. Around 30-40% of species within the orchid family do not produce rewarding nectar in their flowers [6] and instead use different methods to attract pollinators. Orchid flowers may look like another species that provides nectar or they may mimic shelters or brood-sites or even pollinators themselves in order to draw the attentions of individuals looking for a place to shelter or for a potential mate (such as in bumble-bee orchids).
Just as plants have found ways to get pollinated without producing nectar, some animals have found ways to get nectar yet avoid being pollinators. Some flower visitors – known as nectar robbers – will avoid the normal route to the nectar, usually avoiding the floral opening all together and pierce or bite the flower elsewhere to extract the nectar directly without coming into contact with any of the reproductive parts.
For many years it was thought that nectar robbers had a negative or neutral effect on the plants, but over the last couple of decades, research has shown they can also have a positive effect on the plant. Firstly, some nectar robbers do ultimately end up pollinating the plants. Secondly, their presence can modify the behaviours of the pollinators. For example, if flowers have less nectar (because the robbers have extracted some) then pollinators will visit more flowers, increase their foraging range, travel further distances and spend less time at each flower – all of which could improve cross pollination and increase genetic diversity. Maloof et al [7] provide a good review on this topic.  
There has been extensive research done on the characteristics of nectar and its relationship with pollinators. More recent research, however, is starting to unravel the mechanisms by which plants produce nectar – identifying some of the pathways sugars are transported within the plant and concentrated in their nectar [8]. There is still lots to learn.

Sources:

[1] Pacini E, Nicolson SW (2007). Chapter 1: Introduction, In: Nicolson SW, Nepi M, Pacini E (Eds.) Nectaries and Nectar. Springer: The Netherlands. ISBN: 978-1-4020-5936-0. (pages 8-10).
[2] Sasu MA, Wall KL, Stephenson AG (2010). Antimicrobial nectar inhibits a florally transmitted pathogen of a wild Cucurbita pepo (Cucurbitaceae). American Journal of Botany 97 (6): 1025-1030. (link)
[3] Nicolson SW, de Veer L, Köhler A, Pirk CWW. Honeybees prefer warmer nectar and less viscous nectar, regardless of sugar concentration (link).
[4] Bentley BL (1977). The protective function of ants visiting the extrafloral nectaries of Bixa orellana (Bixaceae). J. Ecol. 65 (1): 27.38.
[5] Pyke GH (1991). What does it cost a plant to produce floral nectar? Nature 350: 58-59. doi: 10.1038/350058a0
[6] Johnson SD, Hobbhahn N, Bytebier B (2013). Ancestral deceit and labile evolution of nectar production in the African orchid genus Disa. Biol. Lett. 9 (5): 20130500. doi: 10.1098/rsbl.2013.0500.
[8] Lin IW et al.(2014). Nectar secretion requires sucrose phosphate synthases and the sugar transporter SWEET9. Nature 508: 546-549. doi: 10.1038/nature13082

Bee and Pollination Festival Was Buzzing

Posted on by andy.winfield

Standing in the marquee at the Bee and Pollination Festival felt as close to being in a hive as one could imagine as it was absolutely buzzing with activity! As I weaved my way between the stalls I caught little pieces of conversations going on –“…beekeeping is not easy…first thing you need to do is take a course…”, “…which shutter speed should you use if you’re trying to get the wings of a bee in flight…” and “…have you heard of colony collapse disorder…” . My 5-year old was busy making a giant paper bee, while my husband spoke to the folks at the allotment display and I was admittedly taste testing some of the amazing local varieties of honey. There was something for everyone.

The University of Bristol Botanic Garden hosted the 4th annual Bee and Pollination Festival on the 7th and 8th of September, and as usual, people came out by the hundreds to celebrate bees and other pollinators that perform an essential ecosystem service. We do love our bees!
Nawbash helps a young bee enthusiast spot the queen.

Becoming a beekeeper

I happened to be looking at the display frame set up by the Bristol Beekeepers Association when a gentleman sidled up to Sue Jones, one of the beekeepers on hand to chat with the public, to ask about how one gets into beekeeping.
Sue quickly lays it on the line for him by saying “beekeeping is not easy”, but she quickly adds that some courses and hands-on experience are the first steps one needs to take to get into beekeeping. She’s not trying to discourage anyone from beekeeping, she, like anyone who has kept bees, knows that it is not something you enter into lightly.
Morgan (left) and Zippy (right) making a giant paper bee.

Nawbash Mohammed is another beekeeper on hand and so I begin to speak with her about being a beekeeper. The Bristol Beekeepers Association runs beginner beekeeping courses during the winter to cover the theory about beekeeping. The courses run over three Saturdays. Then, over the spring and summer, the Association offers practical education to cover all the hands-on aspects of beekeeping from opening a hive to handling the frames.

Nawbash has been a beekeeper since 1997, first in Iraq and then when she moved to Bristol in 2011. I ask her about beekeeping in Iraq and how it differs from keeping bees here in the UK. “The principles are all the same,” she says, “but it’s just very different weather and the honey has a very different taste”.  Nawbash describes for me the extremely unique taste of a premium honey in Iraq, made from the nectar collected from mountain flowers. I have to admit to her that this serene image of bees moving from flower to flower in mountain meadows is not the image that comes to mind when I think of Iraq – but I suppose it is the evening news that I have to thank for that. She admits there were additional challenges associated with being in a country fraught with war and political strife, but for the most part the challenges were the same facing beekeepers around the world – disease, mite infestation and colony collapse disorder.
Some of the honey on display and for sale at the festival.

Feeling thoroughly enlightened, I head over to buy a jar of Henleaze honey as I live in the neighbouring community – can’t get more local than that! “That’s my honey!” Nawbash laughs as she sees the jar I pick! Local, and I’ve met the beekeeper…brilliant!

The full experience

After speaking with Nawbash, I found my son and husband floating about the delicious cakes on display at the Bramble Farm table. Bramble Farm is a small landshare farm in Bristol. They keep sheep, pigs and turkeys and grow lots of veg, most of which goes to support the families that share in the upkeep in the farm, but any extra is sold at events such as this.
At the foot of the table lies a basket of some of the largest courgettes I’ve ever seen! However, it is some decadent chocolate cake that has caught the attention of my family! A little hint of fresh mint in the chocolate – delicious!
The apple press that kids took turns operating.

I stop briefly to look at the schedule of activities for the day as I don’t want to miss the demonstration hive talk. In doing so, I start to chat to a woman who is one of nearly one hundred volunteers that are there helping make the weekend’s events run smoothly. Jen Ellington is a committee member of Friends of the Garden as well as one of the Welcome Lodge Volunteers. She’s also opening up her garden next month as part of the Friends’ Open Gardens Programme – each year the Friends open their gardens, large or small, to raise funds for the Botanic Garden. Last year, Jen’s Gardyn raised over £400. Not bad considering her garden is only 15’ x 31’! However, don’t judge the garden by its size as it sounds as though there is plenty to see in this space. “We can’t go out anymore,” said Jen, “so we’re going up – I’m claiming my airspace!”  Within two minutes of listening to Jen’s description of her little garden haven, I’m hooked – so stay tuned to hear more as I will definitely be attending the open garden! The tour is Sunday, 6th October from 2-5pm and you don’t have to be a Friend of the Garden to attend. The address is 4 Wroxham Drive, Little Stoke.
People gather around the demonstration hive.
Next we join the crowd outside the tent that is watching some children work a small apple press to make fresh apple juice. My son obviously has to have a go…after all, we need to wash down the chocolate cake!
We quickly make our way over to the display hive where the beekeeper is taking apart the hive to show the crowd the combs and what it’s like to work a hive.  As the smoke from his smoker rises up through the crowd, the beekeeper explains that “everything runs on pheromones in the hive. As soon as I open the hive, alarm pheromones will be released saying there’s an intruder. The smoke masks those pheromones. So you don’t ever let your smoker go out” – sage advice to any budding beekeepers in the audience.

Always something new to see

Ethel standing proud in a temporary position for the festival.

Of course, we can’t leave without touring the rest of the garden and I must say that the warm days of summer have made things all rather lush.  As my son stares into the pond outside, looking at what seems to be hundreds of dragonfly larvae, I admire the grape vines laden with fruit.

I also notice that Ethel, the giant willow moa bird sculpture, is finished and is on display!
There is a potted orchard, which is new – apples, blueberries, pears, figs, olives, plums and other edible delights line one of the pathways – another reminder of why we should celebrate pollinators!
Down near the glasshouses, Writhlington School has an extraordinary orchid display and inside the glasshouses the lotus plants are in bloom.
A pollinator at work in the garden.

I’ve said it before, but there really is always something new to see in the garden with every season. This weekend marked my second Bee and Pollination Festival and the anniversary of this blog. Having written the blog for the Garden for a year now, I also get to have some insight into some of the plans for the garden and new displays that are on the horizon. I have to say that I have been impressed to no end at how quickly things seem to turn from idea to reality in this garden. Of course, the staff and volunteers that are there every day doing the grunt work behind it all, may feel differently, but for someone who is there every few weeks, things seem to move at an incredible pace. It’s been a wonderful year and I look forward to sharing more about the people, plants, events and research that goes on in this beautiful garden.

There’s plenty of room at the bee hotel

Posted on by andy.winfield
Andy gently pushes some moss out of the way to allow me to peer in. “See there,” he says, “they’ve moved some of this moss and built that wall – this is occupied”.  I’m staring into one of the rooms of the hotel trying not to invade the guests’ privacy, but also too curious to look away. The occupant seems to be out getting a meal or tucked away so as not to be seen by peeping eyes.
An occupied suite at the Botanic Garden’s Bee Hotel.
We are standing in the wildlife area of the Botanic Garden, behind a city skyline of wooden planks. We are staring intently into what might at first glance look like a very artistically and precisely stacked woodpile.  However, this is indeed the Garden’s bee hotel – the sign above it even says so – and there are guests!
The Garden had quite a bit of bamboo left over from the construction of the Chinese herb garden, as well as other materials from some coppicing they had done, and what better way to use them than to create habitat to encourage native bees.


There are over 250 species of native bees and about 90% of these are solitary

Bee-opolis – a city skyline of wooden planks also serves as
potential habitat for solitary bees
Though we often think of hives humming with tens of thousands of bees, most bees in the UK actually lead a solitary lifestyle. This means that a female bee will find or make a burrow where she will rear her larvae on her own.
The nest type and habitat requirement of each species is a little different. The British Science Association created a very informative videoin 2009 as part of their ‘Save Our Bees’ campaign, which talks about the habitat and nests for a variety of native bee species including leafcutter bees, masonry bees, tawny mining bees, cuckoo bumble bees  and carpenter bees.


There’s something for everyone at the bee hotel

The Bee Hotel
The bee hotel was constructed with many possible occupants in mind as well as their diverse habitat requirements.
On the ground floor of the hotel there is a section of large diameter plastic piping that has been sealed at both ends. Protruding out of the side of the pipe is a small piece of bamboo. This is ideal bumblebee habitat as the bamboo provides a narrow entrance but then opens up into the larger pipe.
There are 24 species of bumblebee in the UK, but only eight of these are common. Bumblebees build communal combs either underground or in long tussocky grass, with narrow entrances to discourage curious predators. This ground floor suite of the hotel fits the bill nicely.
As you move up from the ground floor you notice that a diversity of materials have been used including bricks and branches as well as bamboo.
Up closer to the penthouse suites it is mainly bamboo sections that have been stacked and the ends stuffed with moss. The one we are looking at has clear evidence that it has been occupied. Some of the moss has been moved aside and a mud wall has been constructed save for a small hole, about a ¼” in diameter, that is clearly the entrance.
The entire hotel is kept dry with a living roof with semperviren succulents and a skillfully woven willow ‘Bee Hotel’ sign to top it off.
Andy is clear that this is the Garden’s first foray into bee hotels, but this evidence that it’s being used within the first year of construction is encouraging. He is hoping that the diversity of habitats created within the hotel will attract lots of different insects, not just bees.


‘Hopefully it will encourage people to do something in their own garden’

There is global concern about the welfare of bee populations as loss of habitat and food sources, disease, and widespread use of toxic chemicals take their toll on these insects. The loss of bees has significant implications for food security as well as healthy ecosystems in general.
The staff at the Botanic Garden hope the Bee Hotel not only attracts insects, but also inspires visitors to the garden to construct habitats at home and help build resilience for our native pollinators.


Bee habitat doesn’t need to be complicated

Bamboo or branches cut into 10 inch lengths or so with 1/8-3/8” holes drilled 3-8 inches deep are ideal habitat for solitary bees. Bundle a group of these lengths together and hang them in a dry place and you’re done – simple. You can even use dried stems of raspberries, brambles and elder or other similarly sized hollow cane-like vegetation bundled together. 
The key, however, is that the material needs to be dry and it needs to stay dry. It is the wet rather than the cold of winter that can threaten these animals, so keeping the habitat dry is essential.

This is also a great project to do with children – from collecting the materials to maybe even some supervised drilling and then finally watching to see who moves in. I’m looking forward to building some habitats with my son…as well as watching the bee hotel at the Garden over the next year or so to see who has come to stay!

Photos of pollinators at work in the garden this week:

Through the eyes of bees

Posted on by andy.winfield

One of the many fabulous things about the Botanic Garden is that on any given day, you may find scientists out there conducting cutting edge research. There are currently at least seven research programs going on either directly or indirectly with the garden, making it not only a place of beauty, but also a place of scientific discovery.

I recently had the opportunity to speak with a researcher from the University of Bristol’s Ecology of Vision group, who was in the garden photographing flowers with the most bizarre looking camera. I generally take notice of cameras anyway, but this one could hardly be ignored. It was essentially a metal box perched atop a tripod with a lens protruding out one end and an abundance of wires to connect it to a laptop protruding out the other. It simply begged the question – “what is that and what are you doing with it?”
“It’s a POL camera,” said James Foster, a PhD student in the School of Biological Sciences, “we’re imaging the polarized light reflected off flowers. Humans don’t have polarization vision, so we use this camera to create an image that allows us to see what animals with polarized light sensitivity, such as bees, can see. We want to see what flowers are like from a bee’s point of view.”  
James Foster, a PhD student in the School of Biological Sciences,
is using a special camera, built by Dr. Shelby Temple
and Dr. Nick Roberts, to photograph flowers in the
Botanic Garden. The camera characterises and quantifies
all aspects of light polarization and will help researchers see
the flowers from the bee’s point of view.
If, like me, you aren’t confident in your understanding of polarized light, here are the basics. Light travels as a wave, oscillating as it moves through space. As it travels, the wave can oscillate in any number of orientations, up and down, side to side or any angle in between. Polarization refers to either oscillation orientation of the wave (the angle of polarization) or how many waves oscillate in the same direction (the degree of polarization).
Though humans aren’t sensitive to polarized light, many other species are, including many important plant pollinators such as bees.  It’s been known for about 60 years that bees use patterns of polarized light in the sky to navigate, but are they using polarized signals in other aspects of their daily behaviours?  This is the question Foster is trying to answer as part of his PhD.
“We know that it’s the upwards facing portion of the bee’s eye that is most sensitive to polarized light, so we’ve been looking specifically at downwards facing flowers,” said Foster. “Those that seem to be most popular with the bees are usually found as clusters on an inflorescence, often where there are less mature flowers at the top and more mature flowers at the bottom.  I don’t expect that the bee is using polarized light signals to identify the flower as a flower, but once it gets to the flowers it might be using those signals to optimize its foraging activities. For instance, it could influence the bee’s decision to stay on a lower, more mature flower that may be more depleted in nectar or move quickly up to younger flowers that may have more nectar.”
The research is still in its early stages, but if Foster can demonstrate differences in the polarized signals of mature flowers versus younger flowers that also relate to differences in nectar availability, this will be a first step in determining whether bees are using polarized signals for more than just navigation. 
Recent research conducted at the University of Bristol and the University of Cambridge, has shown that conical cells on the surface of the petals of many flowering plants help increase grip for visiting pollinators and are particularly important when the flowers are moving (as they often do in a naturally breezy world).
“Those conical cells would also reduce the degree of polarization of reflections coming off the flower,” added Foster. “What we predict is that there will be areas that will be rich in these conical cells, for gripping, but there will also be regions where the cells are completely flat and these areas will allow polarized reflections that may be important signals for pollinators.”
It’s a tricky thing trying to study a sensory world that we are essentially blind to. However, it probably means that you might see more of James wandering about the garden, POL camera in tow, trying to see the flowers through the eyes of bees.

“WOW! That’s a lot of bees!”

Posted on by andy.winfield

     I could hear my son’s enthusiastic voice coming from somewhere near the front. He had managed to squeeze through the crowd so he could see, while I stood at the back trying to catch a glimpse of what was going on. There were about a hundred of us gathered around a demonstration beehive in the University of Bristol’s Botanic Garden, listening to the beekeeper talk about maintaining beehives. He’d just pulled out a frame from the hive that was absolutely writhing. We all stepped in for a closer look, and despite having no fear of bees, I have to admit that I was grateful for the mist net that separated us. After all, 15,000 is a lot of bees!
An audience gathers around the demonstration hive to
learn about the art of beekeeping. Photo: Nick Wray.
     Last month, my son and I were on a long walk when we happened upon the annual Bee and Pollination Festival at the Botanic Garden. The festival is a joint effort between the Botanic Garden and the Bristol branch of the Avon Beekeepers Association and this was its 3rd year running. This year, the event also partnered with the Bristol City Council’s Allotments Team, who helped to build a small working allotment on-site to celebrate the event’s theme of vegetable growing and allotments. About 1,000 people visited the gardens over the festival weekend and judging by the faces gathered around the demonstration hive, it was a hit whether you were two or ninety-two.
     For my 4-year old, bees mean delicious sweet golden honey. However, for many of us with gardens or allotments, bees have a much greater importance and value in their role as pollinators and the Bee and Pollination Festival was a chance to celebrate this. In the UK, the hard work of pollination is mostly done by insects – bees, butterflies and hoverflies to name a few. Besides our domestic bee, Apis mellifera, the UK has 26 species of bumblebee and 250 species of solitary bee. While we’re at work making a mental list of things that need sorting out in the garden on the weekend, these pollinators are out there doing their thing. In the UK alone, the value of insect-pollinated crops is estimated to be £510 million annually; pollinators perform an extremely valuable ecosystem service that is critical to our future food security.
     It’s important to be reminded of the connection between food and insects, particularly when we consider the plight of our pollinators. Bee and pollinator populations are in decline largely due to loss of natural habitat; monoculture crops and well-grazed pastures do not promote the wild flowers that are essential food for our pollinators. Loss of nesting areas, widespread use of pesticides and disease are also taking their toll.
     The University of Bristol’s Urban Pollinators Project was on hand at the festival to discuss some of these issues. The project is taking a close look at pollinators in urban environments, surveying pollinating insects in the urban centres of Bristol, Edinburgh, Leeds and Reading. The researchers are comparing the biodiversity of pollinators in urban environments with that in reserves and farmland. They’re also trying to identify urban hot-spots of pollinator biodiversity and look at ways of improving diversity and abundance of pollinators in urban areas.
The small working allotment built for the Bee and
Pollination Festival. Photo: Nick Wray.
     While my son stood entranced at the observation hive, searching for the queen, I also had a chance to check out the Bees for Development stand. If you haven’t heard of them, this is an independent organisation that works largely in Africa and Asia promoting more and better beekeeping to help build sustainable livelihoods in developing communities, while also conserving biodiversity. Among other things, the group helps promote the value of bees as pollinators, linking beekeeping to improved crop yields and profits for farmers and stressing their importance for food security.
     We had unfortunately just missed a speaker from Writhlington School’s Orchid Project, but we did meander through the artist exhibits and local nursery displays. We stopped by the Riverford Organic and Butcombe Brewery displays, and of course we couldn’t leave without buying a jar of local honey from the Bristol Beekeepers.

      However, the highlight of the day for me was, without a doubt, seeing my son’s face as he wound his way through the crowd to find me and share his unbridled excitement at seeing all those bees. For him, the smell of the smoke, the hum of the bees and the thrill of spotting the queen among thousands of dancing bees was an incredible window into the world of bees. For me, it was a reminder of the many ways we’re connected to insects and pollinators in particular. For both of us, we’ll have fond memories to think back on each time we enjoy some of our local honey.