Category Archives: Bees

Should honey bee hives be placed on or near conservation sites?

Earlier this week, the East Midlands Environment Agency proudly tweeted that they had placed honey bee hives on an ecologically important site that they own. As you might imagine, the response from pollinator experts such as myself, conservation NGOs, and some beekeepers, was not positive, as you can see if you look at the comments beneath my tweet:

By coincidence, overnight I received a message from someone in the USA asking for advice. Here’s a redacted version of their message:

My community has a 4 acre serpentine barren site that is part of a larger string of these unique barrens ….. Honey bee hives have recently been located adjacent to the barrens. Can you advise me as to the best way to determine whether there are, and to document any, adverse effects to the serpentine barrens native pollinators?

The question of how managed honey bees can impact wild pollinators and the pollination of wild plants is one that frequently comes up in the talks and training that I do. Many beekeepers share these concerns – see for example this very detailed blog post by Mark Patterson.

Going back to the question of how to assess any impacts, the simple answer is that it’s not easy and it relies on having good data. This was my response to my American correspondent:

Ideally you would need to take a before-and-after approach where you have data on things like number of native pollinator species, their abundance (including nest sites), rates of visitation of different pollinators to flowers, and fruit or seed set from particular plants. You’d then compare what was going on before the hives arrived with what’s occurring since their arrival.

If you don’t have the “before” data it’s much more difficult to assess if there has been an impact from the honey bees. However, the advice of most conservation groups is to adopt the “precautionary principle” and not site hives on or adjacent to areas of nature conservation value, especially if they are relatively small areas. See for example the Bumblebee Conservation Trust’s advice: https://www.bumblebeeconservation.org/managed-honeybees/

The precautionary principle is a well established concept across a range of areas, including health and engineering, as well as nature conservation. In the latter it needs to be more widely applied, especially when it comes to questions of where to site honey bee hives, and how many.

Plant-based diets are a problem for bees! A new study of the significance of the ratio of food K:Na in bee ecology and evolution

At the moment Karin and I are in the UK for a couple of weeks. I had work to do as an external examiner at the University of Swansea, plus we wanted to catch up with some family and friends. Our main base has been the home of our mates Ian and Simone and we’ve enjoyed some warm, muggy evenings sitting in their garden chewing the fat. Every now and again my eyes have been drawn to the activities of bumblebees as they move in and out of the foliage of a small Silver Fir. The bees are attracted to the large colonies of an aphid that is feeding on the tree’s trunk, from which they are collecting honeydew, as you can see in the photograph above.

When we think of the diets of bees we automatically think “nectar and pollen”. Honeydew, as a sugar-rich fluid, fits broadly into this concept, though as far as I know there’s been little study of its relative importance as a food source for bees. Aside from a few “vulture bees”, all of the 20,000 or so species are vegetarian. And therein lies a problem. Bees evolved from carnivorous wasps and so the evolution of bees, and their complex ecologies, is tied into this profound dietary shift toward a plant-based diet.

A particular issue that has hardly been investigated until recently is that the ratio of elements within meat is very different to that of plants. In particular, animal tissue has a high ratio of sodium (Na) relative to potassium (K), whereas for plants the ratio is reversed – high ratio of K:Na.

In a new conceptual review paper with my colleagues Zuzanna Filipiak and Michał Filipiak, we have explored the implications of this difference in elemental ratios for bee ecology and evolution, and for the conservation of these important insects. The paper is open access and you can download a copy by following a link in this reference:

Filipiak, Z.M., Ollerton, J. & Filipiak, M. (2023) Uncovering the significance of the ratio of food K:Na in bee ecology and evolution. Ecology e4110. https://doi.org/10.1002/ecy.4110

Here’s the abstract:

Bees provide important ecological services, and many species are threatened globally, yet our knowledge of wild bee ecology and evolution is limited. While evolving from carnivorous ancestors, bees had to develop strategies for coping with limitations imposed on them by a plant-based diet, with nectar providing energy and essential amino acids and pollen as an extraordinary, protein- and lipid-rich food nutritionally similar to animal tissues. Both nectar and pollen display one characteristic common to plants, a high ratio of potassium to sodium (K:Na), potentially leading to bee underdevelopment, health problems, and death. We discuss why and how the ratio of K:Na contributes to bee ecology and evolution and how considering this factor in future studies will provide new knowledge, more accurately depicting the relationship of bees with their environments. Such knowledge is essential for understanding how plants and bees function and interact and is needed to effectively protect wild bees.

Week-long Master’s course in Italy – March 2024 – on Pollination as an Ecosystem Service

I’m excited to announce that in March 2024 I will teach a week-long, Master’s-level residential course entitled “Pollination as an Ecosystem Service” at the University of Pavia in Italy. It will be taught in English. Here’s a summary of the course and a brief description of the the syllabus, which is broadly accurate but subject to change as it develops:

POLLINATION AS AN ECOSYSTEM SERVICE

A 3 credit Master’s course for the University of Pavia

Overview

The pollination of crops by bees, flies, birds, bats and other animals, is an ecosystem service that increases crop yields and quality. This is valued at hundreds of billions of Euros each year to European and global agriculture. In addition, these same animals pollinate around 90% of the world’s wild plants which in turn provide us with ecosystem services such as wild food, flood alleviation, microclimate modification, and carbon capture.

In this course, students will explore pollination as an ecosystem service from its first principles and historical roots through to the latest research findings around the consequences of pollinator decline and climate change. The emphasis of the course is on the students learning by actively participating during classes. Each day has a particular theme and will be a mix of interactive lectures, short video clips to illustrate particular points, discussion seminars (for which they will be expected to do some guided reading) and local excursions.

At the end of the course the students will have a developed a deep understanding of the diversity of pollinators, the ecological nature of their interactions with flowers, and the importance of these relationships to nature and to society.  

Assessment

            At the end of the course, the students will be asked to give a 10 minute presentation based on one of the topics covered in the course, and posed as a question such as “What is….?”, “Why does….?”, “What would happen if….?”, and so forth. The questions will be agreed with me in advance. Presentations will take place on the final day of the course and at the end of each presentation the students will have 5 minutes to answer questions posed by their peers and myself.

Syllabus

Day 1

Theme: Pollinators and pollination – first principles; including historical perspectives, the diversity of pollinators and flowers, and the biology of pollination. Introducing the course assessment.

Excursion: a walk around the local area to observe flowers and pollinators in action.

Day 2

Theme: Pollination as an ecosystem service; including the types of crops that are animal pollinated, how we calculate the value of pollination, and going beyond agriculture to look at the other ecosystem services provided by pollinators; approaches to studying pollinators and pollination.

Day 3

Theme: Pollinator conservation: including reasons for pollinator decline, impacts of climate change, the “politics of pollination”, the consequences of that decline for crop and wild plant pollination, how we can manage and restore habitats for pollinators.

Day 4

Theme: Urban pollinators: understanding the importance of pollinators in an urban setting and in gardens, and how towns and cities support pollinators. Excursion: How is the city of Pavia supporting pollinator populations and what could be improved?

Day 5

Theme: Summing up what we’ve learned, followed by assessed student presentations.

The course is open to all and there’s details of how to apply (in Italian and English) in the following link: https://portale.unipv.it/it/didattica/corsi-di-laurea/ammissioni/casi-particolari-di-iscrizione/iscriversi-ai-corsi-singoli

The brochure with all available courses can be downloaded here: http://news.unipv.it/?p=84031

I’d be very happy to talk with other universities who might be interested in running such a course.

If you have any questions, please use my Contact page to get in touch.

A “weed” that you should be eating and an introduction to our new garden

It’s been a rather nomadic couple of years. After Karin and I sold our house in Northampton, we travelled around in the UK and then in Denmark, renting places as we needed them, plus we spent a month in Kenya. We’ve now become more settled in Sjælland and, after some deliberation about whether to buy a house or continue renting, we’ve reached a compromise and bought into an andelsbolig, one of the many Danish cooperative housing schemes – see this article in The Guardian for more details.

The development of twenty-eight small properties has been newly built to the highest standards of insulation and is plugged into the district heating system which uses a combination of solar warming and gas (in part using methane generated from food waste).

It’s nice to have a garden again. I hadn’t realised how much I’d missed having a space in which to plant and potter. All gardens present challenges, of course, and this one is no exception. Until about 600 years ago the area was under the shallow Kattegat sea. It’s now above sea level due to post-glacial rebound and in fact this whole region of Odsherred is a UNESCO Global Geopark because of the postglacial landscape.

What this means for us is that we are gardening on “soil” which has a very high sand content and is filled with stones, large and small.

Added to that, we’re in one of the driest parts of Denmark (certainly this year) and a persistent coastal wind rapidly strips the moisture from the soil. So as we dig up or find large stones we are using them around plants to retain water and mulching with the smaller stones that we find in abundance. As yet we don’t have any rain water butts so we’re using the kitchen water from washing up to supplement the hosepipe.

It’s not easy gardening here, but we like a challenge and we’re calling in favours from friends and family to provide us with cuttings and divisions of plants from their own gardens, which should mean that they are better adapted to the local conditions than most of the shop-bought plants. We’ve also started a small vegetable and fruit patch and planted apples and pears around a paved patio that over time we will train as self-supporting espaliers.

Gradually we’ll fill up the space and move things around as needed. But for now I’m also interested in seeing what plants come up spontaneously, especially the annual species that are benefitting from the disturbance. I don’t use the term “weed” to refer to these: weeds are just plants in the wrong place at the wrong time. Many such plants are ecologically important, especially as nectar and pollen sources for bees and other insects. This includes Common Bugloss (Anchusa officinalis) with its richly purple, velvet-textured flowers.

Another plant that we are tolerating is a fast-growing relative of spinach that’s variously called Goosefoot or Fat Hen (Chenopodium album). I’d long known that it was edible (it’s grown as a crop in parts of Asia) but until last night I’d not cooked with it.

In fact it’s delicious! I threw some roughly chopped leaves and stems into a mushroom omelette and I have to say that it was better than any commercial spinach I’ve bought or grown. In particular, the texture is much nicer as the leaves are very water-repellant which mean that they don’t absorb as much moisture during cooking. Highly recommended as an alternative to spinach but make sure you correctly identify the plant before you try it – there’s some good advice on this website: https://www.wildfooduk.com/edible-wild-plants/fat-hen/.

As well as Fat Hen we also have the close relative Tree Spinach (Chenopodium giganteum), with it’s beautiful magenta-tinged leaves, coming up in the garden. I’m looking forward to trying that too:

I’ll try to post more as the garden progresses, if I have time. But as I mentioned yesterday, even though the manuscript is complete and submitted to the publisher, there’s still lots to do on my next book! Have a good weekend.

Pesticides and pollinators: please sign this petition!

As part of our roles as ambassadors of the new conservation organisation Restore (more of which later this year), several of us including Dave Goulson, George McGavin, and myself, are promoting this online petition to get the government to take the issue of neonicotinoid pesticides seriously. Here’s some text from Dave explaining the situation with a link to a petition that you can sign:

“For three years in a row our government has granted farmers special permission to use banned neonicotinoid pesticides on sugar beet. This is contrary to the expert advice of their own Expert Committee on Pesticides, who specifically recommended that permission should not be granted.  It also flies in the face of a huge body of scientific evidence showing that these chemicals are phenomenally toxic to all insect life, and that their use on any crop contaminates soils, hedgerow plants, and nearby streams and ponds for years to come. We are in a crisis, with insect populations in freefall. It is about time our government woke up to this, and acted accordingly. This petition https://petition.parliament.uk/petitions/631948 is a necessary means of holding the government to account. Please sign and share, as signing will ensure the issue is debated in Parliament.”

This petition now has more than 15,000 signatures which ensures that it gets a response from the Government. If it reaches 100,000 mark, it will trigger a debate in Parliament. Please sign and promote this important initiative! 

Pollinators and the UN Sustainable Development Goals – free webinar on Monday!

There’s been a lot of discussion recently about how pollinators can contribute to the United Nations’ 17 Sustainable Development Goals. It’s a topic that I reflected on in Pollinators & Pollination: Nature and Society, and I’ve seen a few papers and articles that raise the subject – see here for instance. This free webinar on Monday 27th March is therefore very timely! To register, follow this link: forms.office.com\r\T5HrW0VZvS

Although I’m one of the speakers, I can’t make it in person as I’ve got teaching commitments at Roskilde University, so I’ve recorded my ten minute piece and I’m happy to answer questions via the Contact page on my website.

Join me tomorrow evening for an online talk about pollinators in the UK!

It’s been a couple of years since I last did a talk or workshop for the Wildlife Trust for Bedfordshire, Cambridgeshire & Northamptonshire. But I’m pleased to say that they’ve invited me back and you can join me tomorrow evening for an online introductory talk about pollinators and pollination in the UK.

The talk starts at 7pm UK time and full details of how to sign up are in the link below:

https://www.wildlifebcn.org/events/2023-02-22-online-pollinators-and-pollination-professor-jeff-ollerton

I look forward to seeing some of you there!

Soybean is more dependent on bee pollination in the tropics – a new study just published

It’s been an interesting start to the year in the world of pollinators and pollination. The European Union has revised its 2018 initiative for pollinator conservation with an update called “A New Deal for Pollinators“. At the same time the UK Government has released its plans for Post-Brexit farm subsidies, many of which focus on environmental action that can support pollinators, such as planting hedgerows. I think that it’s fair to say that there’s been a mixed response to these planned subsidies. There’s also mixed news in Butterfly Conservation’s State of the UK’s Butterflies 2022 report. The headline figure is that 80% of butterflies in the UK have decreased since the 1970s. However there are enough positive conservation stories in that report to demonstrate that this decline does not have to be irreversible, we can turn things around.

Against this wider backdrop of pollinator actions, I was pleased to have a new research paper published this week, which is an output from the SURPASS2 project with which I’ve been involved. Led by Brazilian researcher Nicolay Leme da Cunha, this paper assess the variability of soybean dependence on pollinators. Although soybean is one of the most widely grown crops globally, there’s still much that we don’t understand about which of the many different varieties have improved yields when visited by bees, and which are purely self-pollinating. One of our main findings was that for some varieties, especially in the tropics, an absence of pollinators results in a decline in yield of about 50%.

The paper is open access and you can download a copy by following the link in the reference:

da Cunha, N.L, Chacoff, N.P., Sáez, A., Schmucki, R., Galetto, L., Devoto, M., Carrasco, J., Mazzei, M.P., Castillo, S.E., Palacios, T.P., Vesprini, J.L., Agostini, K., Saraiva, A.M., Woodcock, B.A., Ollerton, J. & Aizen, M.A. (2023) Soybean dependence on biotic pollination decreases with latitude. Agriculture, Ecosystems & Environment 347, 108376

Here’s the abstract:

Identifying large-scale patterns of variation in pollinator dependence (PD) in crops is important from both basic and applied perspectives. Evidence from wild plants indicates that this variation can be structured latitudinally. Individuals from populations at high latitudes may be more selfed and less dependent on pollinators due to higher environmental instability and overall lower temperatures, environmental conditions that may affect pollinator availability. However, whether this pattern is similarly present in crops remains unknown. Soybean (Glycine max), one of the most important crops globally, is partially self-pollinated and autogamous, exhibiting large variation in the extent of PD (from a 0 to ∼50% decrease in yield in the absence of animal pollination). We examined latitudinal variation in soybean’s PD using data from 28 independent studies distributed along a wide latitudinal gradient (4–43 degrees). We estimated PD by comparing yields between open-pollinated and pollinator-excluded plants. In the absence of pollinators, soybean yield was found to decrease by an average of ∼30%. However, PD decreases abruptly at high latitudes, suggesting a relative increase in autogamous seed production. Pollinator supplementation does not seem to increase seed production at any latitude. We propose that latitudinal variation in PD in soybean may be driven by temperature and photoperiod affecting the expression of cleistogamy and androsterility. Therefore, an adaptive mating response to an unpredictable pollinator environment apparently common in wild plants can also be imprinted in highly domesticated and genetically-modified crops

Orchid pollen comes pre-packaged

The other day Karin bought a Miltonia orchid to add to the ever-expanding collection of orchids she’s accumulating. It’s nowhere near as large as the collection she accumulated in our old place in the UK – part of it is pictured in this old post of mine – but it’s only a matter of time. This morning I showed her how to extract orchid pollen from the flower and her squeals of delight were something to hear!

As you can see in the image above, these orchids package their pollen into discrete structures that we term “pollinia” – two of them in this case, though the form and number of pollinia vary between different groups of orchids. The pollinia plus the sticky organ that attaches them to a pollinator is collectively termed a “pollinarium”. The only other plants that present their pollen in this way are my beloved asclepiads in the family Apocynaceae. The orchids and the asclepiads are only very distantly related to each other so this is a clear example of convergent evolution, where both plant groups have come up with the same solution to a problem. In this case, the problem is probably that bees collect a lot of pollen which has a reproductive cost for plants. Packaging the pollen in this way prevents bees from stealing it, amongst other advantages.

If you want to look at this yourself, you’ll find the pollinaria tucked under the front of the central “column” of the flower, which comprises the fused male and female reproductive parts. Just take a fine needle and gently stroke the underside of the column. In the image below, taken just after we extracted the pollinarium, you can see the “anther cap” which covered them lying just below the column.

It’s possible to learn a lot about botany from studying even common houseplants such as these!

Plant-pollinator meta-network of the Kashmir Himalaya: a new study just published

Although we sometimes like to think that we have a “global” perspective on plant-pollinator interactions, in truth there are large parts of the world where we have little or no information. That’s especially true of biodiversity hotspots. One such hotspot is the Kashmir Himalaya, a relatively small area (just 135 km long by 32 km wide) that nonetheless contains an estimated 2,000 species of flowering plant, more than 150 of which are endemic to the area. In addition, over 1,280 insect pollinator species have been described, including at least 29 species of bumblebees and as many as 40 species of butterflies.

Recently I’ve been collaborating with Dr Zubair Rather from the University of Kashmir and his colleagues on a data set that represents the first network analysis of plant-pollinator interactions from the region. The network is presented at a large spatial scale – what is often termed a “meta-network”. As Dr Kit Prendergast and I noted in our recent paper, scale matters when it comes to analysing these sorts of networks. Nonetheless (to quote the current paper):

“meta-networks represent the “backbone” of plant-pollinator interactions to which smaller, local networks are attached”

Even at this very large scale we’re seeing some fascinating patterns emerging with respect to the plants, for example the importance of cultivated apples in supporting the wider network of flower visitors. Also notable, and I believe demonstrated for the first time, is the fact that both the indigenous Asian Honeybee (Apis cerana) and the introduced Western Honeybee (A. mellifera) utilise exactly the same, extremely broad array of plants from which to collect nectar and pollen.

Our Kashmir meta-network is, hopefully, the starting point for further work on plant-pollinator interactions in this fascinating and diverse part of the world. The paper is published in a special issue of the journal Flora that’s dedicated to the importance of natural history when considering the ecology and evolution of plant-pollinator relationships. The special issue is a celebration of the work of Professor Marlies Sazima and is edited by Dr Pedro Bergamo.

Here’s the reference with a link to download a free copy which should be valid up to and including 23rd January 2023:

Rather, Z.A, Ollerton, J., Parey, S.H., Ara, S., Watts, S., Paray, M.M & Khuroo, A.A. (2022) Plant-pollinator meta-network of the Kashmir Himalaya: structure, modularity, integration of alien species and extinction simulation. Flora (in press)

Here’s the abstract:

Plant-pollinator studies are increasingly using network analysis to investigate the structure and function of such communities. However, many areas of high biodiversity largely remain unexplored in this way. Our study describes a plant-pollinator meta-network from an understudied biodiversity hotspot, the Kashmir Himalaya, where we specifically investigate plant-pollinator network nestedness and modularity, as well as the influence of alien species and the impacts of simulating species extinctions on network structure. Natural history observations were used to document the meta-network between 230 plant and 80 pollinator species forming 1958 (11% of the possible) interactions. Among the plants Malus domestica and among the pollinators Apis mellifera and A. cerana formed the largest number of interactions with significant influence over the whole network. Network cumulative degree distribution depicted a higher number of degree levels in pollinators than plants. A moderately high number of realized interactions were revealed, thereby indicating potential structural and functional stability in the network. Eight strongly defined modules were observed in the network which varied in their composition. For example, the Ephedra module exclusively comprised of native species whereas the Apis module comprised of all the four different types of interacting species (i.e. native and alien plants and pollinators) and also integrated the highest number of alien species. In the network overall, 40% of interactions were by alien species, reflecting how well these were integrated. Extinction simulations suggested that the network would collapse more quickly when the most connected pollinators are removed, rather than the most connected plant species. Our study is the first assessment of a plant-pollinator network from this Himalayan biodiversity hotspot; and will help to inform the ecological and economic implications of plant-pollinator interactions in an era of global biodiversity crisis.