Category Archives: Pollination

Insect pollination in deep time – a new review just published

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As a teenager one of my main interests was collecting fossils. In search of specimens I wandered for hours, scouring the Carboniferous coal shale heaps and Permian reef outcrops of my native Sunderland. I spent so much time bothering the geology curator at the local museum with my inquiries that he offered to host me for a year as the placement part of my college course. If I had been able to convince my tutors that paleontology was really just biology in deep time I may have ended up as a professional fossil researcher. But it was not to be and instead I spent a (mostly happy) year working in the microbiology laboratory of a local brewery.

My interest in the ecology of the past has never left me, and over the years I’ve contributed a few articles to journals commenting on the latest fossil findings as they relate to pollination and flowering plant evolution. So I was delighted to be asked by Spanish paleontologist David Peris to help with a new review of insect pollination in deep time, led by PhD candidate Constanza Peña-Kairath. That review has just been published in Trends in Ecology & Evolution, and for the next 50 days it’s available for free download by following the link in the reference:

Peña-Kairath, C., Delclòs, X., Álvarez-Parra, S., Peñalver, E., Engel, M.S., Ollerton, J. & Peris, D. (2023) Insect pollination in deep time. Trends in Ecology & Evolution (in press)

Here’s the abstract:

Inferring insect pollination from compression fossils and amber inclusions is difficult because of a lack of consensus on defining an insect pollinator and the challenge of recognizing this ecological relationship in deep time. We propose a conceptual definition for such insects and an operational classification into pollinator or presumed pollinator. Using this approach, we identified 15 insect families that include fossil pollinators and show that pollination relationships have existed since at least the Upper Jurassic (~163 Ma). Insects prior to this can only be classified as presumed pollinators. This gives a more nuanced insight into the origin and evolution of an ecological relationship that is vital to the establishment, composition and conservation of modern terrestrial ecosystems.

Announcing my new book: “Birds & Flowers: An Intimate 50 Million Year Relationship”

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For the past year I’ve been keeping a secret from all but a few trusted confidantes: the subject and title of my next book! My publisher – Pelagic – has now announced it on their website and so it’s time to make it public. “Birds & Flowers: An Intimate 50 Million Year Relationship” will be the first book that covers bird pollination in its entirety, going beyond just hummingbirds, sunbirds and honeyeaters, to consider the more than 60 other bird families that interact with flowers, and the tens of thousands of plants that rely on them as pollinators. You can read more about it on Pelagic’s website.

The 3D mock-up of the cover shown above features an illustration by my good friend Stephen Valentine, a very talented artist who you may remember produced this painting of waxwings that Karin bought for my birthday a few years ago. I’m extremely pleased with how Pelagic have incorporated this into the design of the cover.

The book will be available by autumn I hope, if my writing schedule goes to plan!

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

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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!

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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

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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

Introducing Ceropegia stylesii – a novel species of “Brachystelma” from South Africa

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This is a guest post by Dr Annemarie Heiduk about a new species that she’s recently described.

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In an earlier blog post about the discovery of a novel Ceropegia species, Jeff’s finishing sentence was: “I wonder what else is still waiting to be discovered in the stunning grasslands of South Africa?”

I am happy to provide a first answer to this question: Ceropegia stylesii.

This new species does not have the tubular kettle-trap flowers typical of Ceropegia, which temporarily trap pollinators, but open-rotate corollas where the gynostegium (fused male and female reproductive organs) is freely accessible to pollinators. So, in the traditional sense, C. stylesii is not a Ceropegia. This needs some explanation here!

Ceropegia is a genus in the plant family Apocynaceae (Jeff’s favourite family of plants!) and therein the genus is placed in the subfamily Asclepiadoideae which originally was a family on its own (“Asclepiadaceae”).

Within this subfamily, the genus Ceropegia belongs to the Stapeliinae – a subtribe which comprises ca. 720 species. About 220 species thereof have exciting looking and very cleverly designed kettle-trap flowers which attract small flies as pollinators via deceptive strategies (see http://plantlifesouthafrica.blogspot.com/2019/07/plantlife-sa-volume-473-july-2019.html). The remaining species in Stapeliinae are the well-known stem-succulent stapeliads (ca. 355 species in >30 genera) and ca. 140 species known as Brachystelma.

With increasingly better molecular methods to study the evolutionary relationships of species in Stapeliinae, the traditional grouping of the species was illuminated as being artificial, i.e., species with kettle-trap flowers are not actually a natural group and Brachystelma species are scattered among them; the stapeliads are also nested in Ceropegia but as a single (monophyletic) group. These results based on DNA-sequence similarities are not compatible with the traditional generic concept in Stapeliinae, and as a result, changes were instigated.

Some colleagues wish to see all 720 species of Ceropegia, Brachystelma and the stapeliads merged into one single large genus Ceropegia, a solution which would entail more than 400 new name combinations. Others prefer to adopt a less dramatic change of concept and only include Brachystelma in an enlarged Ceropegia while keeping the stapeliads separate based on their monophyly and distinct vegetative features. This pragmatic solution considers both taxonomic and phylogenetic facts and reduces the previously multiple cases of paraphyly to a single case. More importantly, it avoids hundreds of name changes in the group. Both concepts are correct in their own right and justified, so it is a personal decision which one to follow.

The newly described species C. stylesii would traditionally have been placed in Brachystelma as it is lacking tubular kettle-trap flowers. After the inclusion of Brachystelma into Ceropegia, C. stylesii is placed within section Bowkerianae – a group comprising species both with and without tubular kettle-trap flowers. With the description of C. stylesii, the section now has 15 members of which 10 have open-rotate flowers. Among these, C. stylesii appears to be most closely related to C. gerrardii from which it can only readily be distinguished when in flower (see the lower most image above).

The flowers of C. stylesii superficially look like miniature versions of a dark-flowered form of C. gerrardii, which growths in the same habitat. C. stylesii flowers are only about 6 mm in size whereas those of C. gerrardii are about three times larger. While C. gerrardii occurs in grasslands throughout eastern South Africa, C. stylesii is believed to be endemic to Ngome, where it is known from two localities with a total of less than 10 plants. After the recent discovery of C. heidukiae at Ngome, the area revealed another outstanding member of this amazing plant group, and thereby once again proves its conservation importance.  

C. stylesii is named for David Gordon Alexander Styles, botanical explorer and collector, to honour his valuable contribution to botanical knowledge in South Africa. David is renowned for “…his daring nature to go leaps and bounds for the specimen he is interested in” (see Chetty 2021), a statement I can readily confirm based on personal experience. Many of David’s collections (by now well over 6000 specimens donated to various herbaria) are novelties awaiting to be described. With C. stylesii, a total of five plant species bear his name. I am delighted that eventually a Ceropegia species could be named for him as David’s knowledge on the distribution and habitats of these special plants is of great value to my research on this plant group.

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

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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.

Books as gifts this Christmas – here’s some ideas for adults and children

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Although we are still in the early part of November, it’s never too soon to be thinking about buying Christmas gifts for friends and family. And what better gift than a book? Here’s a few suggestions for some that I’ve read this year that I think will make fine presents.

Who doesn’t love a good story, and Stephen King is a master storyteller. I’ve really enjoyed his more recent novels and Billy Summers stands out for me. It’s part thriller, part romance, and as always there’s a little touch of the uncanny. Very different, but just as much a page turner, is The Ministry for the Future by Kim Stanley Robinson. Although Robinson is known as a science fiction writer, this novel is set in the near future when climate change breakdown is forcing governments and businesses into making radical changes. As much as anything this is a road map for how we can get ourselves out of the current climate crisis.

Talking of which, Michael Mann’s The New Climate War should be read by everyone interested in understanding how big corporations have colluded with the media and governments to trivialise and misrepresent the problems that we currently face. I reviewed this and a book about the insect biodiversity crisis, Silent Earth by Dave Goulson, in this blog post.

If you are looking for a book to help young children understand the importance of bees and other pollinators then I can highly recommend Can We Really Help the Bees? by Katie Daynes and Róisín Hahessy, for which I acted as science advisor.

For the ornithologically minded you might want to consider the lavishly illustrated Hummingbirds: A Celebration of Nature’s Jewels by Glenn Bartley and Andy Swash. Those who love writing and art with an environmental focus would appreciate an annual subscription to Dark Mountain, which gives you two beautifully produced volumes every year. A couple of my essays appeared in earlier volumes and the quality of the contributions never fails to impress me.

There’s lots of great natural history authors and books to choose from on Pelagic Publishing’s list, including of course my own Pollinators & Pollination: Nature and Society! I especially enjoyed Ian Carter’s recent memoir Human, Nature: A Naturalist’s Thoughts on Wildlife and Wild Places.

For the budding or experienced cook, Niki Webster’s Rebel Recipes serves up some amazing vegan dishes that Karin and I have really enjoyed trying. And speaking of my wife, of course I have to include her Essential Companion to Talking Therapy as the perfect gift for anyone considering or currently undergoing counselling or therapy, or who is thinking about becoming a practitioner.

Finally, if you’re looking for particular book ideas or just like browsing through lists of what others recommend, there’s lots of inspiration over at the independent Shepherd site.

I hope that you’ve found this useful. Feel free to comment with suggestions for other books that you’ve enjoyed.

Food system resilience: concepts, issues and challenges – a new, open access review just published

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Human populations across the planet are locked into complex economic, agricultural, social, political and ecological systems that provide them with food or, under extreme circumstances, fail to provide that sustenance. The complexity of these food systems requires that they are studied from a multi-disciplinary perspective because no one subject, or individual, can possibly do justice to this crucial topic.

One of the most pressing questions related to food systems is how we ensure that they are resilient to the current and future challenges of war, pandemics, climate change, economic shocks, biodiversity loss (including pollinators, of course), and a host of other factors. Some of these are predictable, others are not, except that recent and distant history tells us that such challenges are always going to be a feature of our societies and we need to prepare as best we can. This review of our current understanding of resilience in food systems is therefore timely and important.

My involvement with this review stems from the work I did with with Simon Potts and Tom Breeze at the University of Reading, Helen Lomax (University of Huddersfield) and Jim Rouquette (Natural Capital Solutions) on a project called Modelling landscapes for resilient pollination services in the UK (funded by BBSRC 2017-2020). That project, in turn, was part of a much larger funding programme entitled Resilience of the UK Food System in a Global Context. You can expect to see more publications coming from this research in the future.

Here’s the full reference with a link to the open access paper:

Zurek, M., Ingram, J., Bellamy, A.S., Goold, C., Lyon, C., Alexander, P., Barnes, A., Bebber, D.P., Breeze, T.D, Bruce, A., Collins, L.M., Davies, J. Doherty, B., Ensor, J., Franco, S.C., Gatto, A., Hess, T., Lamprinopoulou, C., Liu, L., Merkle, M., Norton, L., Oliver, T., Ollerton, J., Potts, S., Reed, M.S., Sutcliffe, C. & Withers, P.J.A. (2022) Food system resilience: concepts, issues and challenges. Annual Review of Environment and Resources 47: 22.1–22.24 doi.org/10.1146/annurev-environ-112320-050744

Here’s the abstract:

Food system resilience has multiple dimensions. We draw on food system and resilience concepts and review resilience framings of different communities. We present four questions to frame food system resilience (Resilience of what? Resilience to what? Resilience from whose perspective? Resilience for how long?) and three approaches to enhancing resilience (robustness, recovery, and reorientation—the three “Rs”). We focus on enhancing resilience of food system outcomes and argue this will require food system actors adapting their activities, noting that activities do not change spontaneously but in response to a change in drivers: an opportunity or a threat. However, operationalizing resilience enhancement involves normative choices and will result in decisions having to be negotiated about trade-offs among food system outcomes for different stakeholders. New approaches to including different food system actors’ perceptions and goals are needed to build food systems that are better positioned to address challenges of the future.

Are cactus pollination systems more specialised in the tropics? A new study suggests yes…and no!

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The question of whether interactions between different species are more specialised in tropical environments (as theory predicts) has intrigued me for a couple of decades. In fact it’s just occurred to me that August 2022 was the 20th anniversary of my paper in Oikos co-authored with Louise Cranmer entitled: Latitudinal trends in plant-pollinator interactions: are tropical plants more specialised? That paper was one of the first to seriously challenge an idea that was long-embedded in the scientific and (especially) popular literature, that tropical ecology was in a sense “special” and that the ways in which species parasitised, consumed, or engaged in mutualistic relationships in the tropics was different to what was happening in the subtropics and temperate zones.

Since then I’ve written about this subject in a number of publications, most recently in my book Pollinators & Pollination: Nature and Society and it’s inspired some other researchers to address the topic.

One of the real challenges with asking questions about how plant-pollinator relationships change over large geographical areas is obtaining good, robust data to analyse. It’s a challenge to convince science funding agencies to give money to spend many years travelling the world and collecting the kind of data that are needed. However we can gain some idea of the patterns, and potential processes, that drive the macroecology of plant-pollinator interactions by piecing together databases of interactions for particular taxa, gleaned from published and unpublished sources.

That’s what we have done for the family Cactaceae in a new study led by Pablo Gorostiague from the Universidad Nacional de Salta in Argentina. This collaboration started when Pablo visited Northampton back in 2018 and spent some time with my research group, including helping out with field work in Tenerife. Since then the usual issues (work, COVID, etc.) have delayed publication of our paper, but now it’s finally out. Amongst other results we find that, yes, tropical cacti are pollinated by fewer species on average (though it’s hugely variable – see the figure above) but that functional specialisation (i.e. the number of pollinator guilds that are used by species) is no different in the tropics compared to the extra-tropics (that’s the figure at the end of this post).

The full reference with a link to the paper is below; if anyone wants a PDF, please send me a message via the Contact page:

Gorostiague, P., Ollerton, J. and Ortega-Baes, P. (2022) Latitudinal gradients in biotic interactions: Are cacti pollination systems more specialized in the tropics? Plant Biology https://doi.org/10.1111/plb.13450

Here’s the abstract:

Biotic interactions are said to be more specialized in the tropics, and this was also proposed for the pollination systems of columnar cacti from North America. However, this has not yet been tested for a wider set of cactus species. Here, we use the available information about pollination in the Cactaceae to explore the geographic patterns of this mutualistic interaction, and test if there is a latitudinal gradient in its degree of specialization.

We performed a bibliographic search of all publications on the pollination of cacti species and summarized the information to build a database. We used generalized linear models to evaluate if the degree of specialization in cacti pollination systems is affected by latitude, using two different measures: the number of pollinator guilds (functional specialization) and the number of pollinator species (ecological specialization).

Our database contained information about the pollination of 148 species. The most frequent pollinator guilds were bees, birds, moths and bats. There was no apparent effect of latitude on the number of guilds that pollinate a cactus species. However, latitude had a small but significant effect on the number of pollinator species that service a given cactus species.

Bees are found as pollinators of most cactus species, along a wide latitudinal gradient. Bat and bird pollination is more common in the tropics than in the extra-tropics. The available information suggests that cacti pollination systems are slightly more ecologically specialized in the tropics, but it does not support any trend with regard to functional specialization.