Category Archives: Bees

Dancing with wolves: more from SCAPE 2014

Tovetorp Research Station has a small colony of wolves, though we weren’t allowed to visit them as they are being observed as part of a study of canid behaviour. But I did see a White-tailed eagle (Haliaeetus albicilla) which was just as good! And on the last night of the SCAPE meeting there was the usual post-banquet bout of Scando-European dancing by the younger members of the conference, which gave me the idea for the title of this post.

But on to the science! I’ve already talked a little about some of what I learned or was excited about from the Thursday & Friday talks, and Saturday’s sessions continued in the same vein, with interesting and novel research in abundance, including:

species in 166 different plant families lack nectar as a reward, with an estimated 15-20,000 species (from 72 families) utilising buzz pollination (Mario Vallejo-Marin, University of Stirling)
Alocasia sarawakensis employs a brood-site pollination system analogous to figs and yucca moths, but without destroying any ovules (Florian Etl, University of Vienna)
floral scents are more complex in their geographical and anatomical distribution than we realised, and may be used to cheat pollinators into thinking there is a reward in a flower (Magne Friberg, Amy Parachnowitsch & Rosie Burdon, Uppsala University)
exposure to neonicotinoid pesticides can cause very subtle effects on bumblebee behaviour when they forage on apple blossom, which doesn’t seem to translate into an effect on apple pollination (Dara Stanley, Royal Holloway)
it may be possible to assign environmental niches to native and introduced pollinators in order to understand how invasive species out-compete native ones (Jonas Kuppler, University of Salzburg)
functional diversity of floral traits is greater than that of vegetative traits in alpine plant communities (Robert Junker, University of Salzburg)

As I said before, these are just some of the highlights, there were many others. My own talk was about the rate of extinction of bees and flower-visiting wasps in Britain, involving some new analyses I’ve been doing with colleagues over the past 6 months or so. The work seemed to be mostly well received, though there was scepticism from some quarters about the methods we’ve used, and a suggestion that there are better ways to assess extinction which I’m going to follow up.

I returned to the UK at 7pm last night. On the drive home from the airport, Karin asked me what I’d most enjoyed about the conference. The answer was all of it, of course, but what these meetings really provide is an opportunity to discuss science in an informal, friendly (though rigorous and argumentative!) atmosphere, outside the formal talks. Not just the science itself, but also the way we do science, manage our careers, and communicate our findings. I spent some time chatting with Amy Parachnowitsch, who blogs over at Small Pond Science, and her research student Rosie Burdon about the role of blogging in science communication and what we’re aiming to do by releasing these thoughts out onto the internet. Paradoxically these are conversations that are best had face to face I think!

The problem with SCAPE is that it’s over and gone too quickly, but perhaps that’s the point: it leaves us wanting more and looking forward to next year, when it will be in Denmark. Thanks again to the organising committee for a stimulating and enjoyable few days. Any pollination scientists, at all stages of their career, who wish to come along to future SCAPEs would be guaranteed a warm welcome and should drop the organisers a line to be added to the mailing list, or search for the Facebook page of the group and ask to be added.

The bare-foot conference: SCAPE 2014

7 Replies

Not strictly bare-foot, most of us are wearing socks and padding around the Tovetorp Research Station in Sweden, where outdoor shoes are banned in the building. The Scandinavian Association for Pollination Ecology is holding its 28th annual meeting here, starting Thursday evening with three initial talks, and continuing all today. I’ve posted about SCAPE previously: it’s my favourite conference by a long margin, friendly and informal and attracting some great science. Although I missed it last year due to my trip to Brazil, coming back this year is a little like coming back to a family gathering, where as well as the elder aunts and uncles, there’s also a large group of younger nieces and nephews, and some long-lost cousins – it’s a great mix of older professors, and newer PhD students.

This is a quick post before we have dinner and the bar opens. In the last 24 hours I have learned a lot about pollination ecology that I didn’t know before, including:

Vincetoxicum hirundinaria does not vary in its outcrossing rate, regardless of the size of population (Anne Muola, Swedish Agricultural University)
Arum italicum and Arum maculatum hybridise in some populations (Marion Chartier, University of Vienna)
variable weather conditions can result in low bumblebee numbers and increased fly pollination in a north American mountain plant community (Diane Campbell, University of California)
nocturnal pollination by moths is more common than expected in Spanish mountain plant communities (Marcos Mendez, Rey Juan Carlos University)
“double mutualists” that both pollinate plants and disperse their seeds seem to be more common on islands than elsewhere (Jens Olesen, Aarhus University)
colour “purity” is more important than other aspects of flower colouration (Klaus Lunau, Heinrich-Heine University)
there’s very little evidence to support any of the current hypotheses regarding the evolution of andromonoecy (Marcos Mendez, again!)

Those are just a few of the highlights from a conference that’s showcasing some of the best pollination ecology research currently being conducted. Looks like dinner’s ready so I’ll sign off for now. My talk is tomorrow at 4.30pm – wish me luck!

Biodiversity miscellany

2 Replies

It’s been a few weeks since my last post, not because I’ve had nothing to say, but rather because there’s been too much to say, and too much to do to have time to say it! A lot has been happening personally, professionally and in the wider world that I could have talked about, so I’ve summarised a few things below.

Late September saw the start of a new academic year, with all of the organisation and effort that entails. Recruitment in our Department of Environmental and Geographical Sciences is healthy and the new intake of students are bright and keen. In addition to my usual teaching and research in the Department I’ve been asked to take on the role of Head of Research and Enterprise for the whole School of Science and Technology. Which will be interesting as it covers a vast range of subjects, including computing, leather technology, and engineering, as well as the environmental and geographical area with which I’m more familiar. It’s a two-year post which should be enough time to do some good work.

The Local Nature Partnership annual meeting took place at the university on 25th September. Parliamentary Under Secretary of State for natural environment and science Lord de Mauley popped up again, and gave a better and more focused speech than he did previously at the recent Nature Improvement Area conference in London. It’s a pity he didn’t stay for the afternoon session as there was a very interesting presentation from the company who are developing the Rushden Lakes site in the Nene Valley. Part of the development is a Site of Special Scientific Interest (SSSI) and it’s within the Special Protection Area, designated for over-wintering birds. The Wildlife Trust is working closely with the developers and, if the latter deliver what they say they will deliver, it will enhance and protect the site even further. Time will tell; you can watch a video of the plans here.

Lots of news stories related to biodiversity and conservation have appeared recently, including a scare-mongering piece in the Guardian that “The Earth has lost half its wildlife in the last 40 years” according to a report from WWF. Of course that’s journalistic crap and the report does not say that at all. I can’t sum it up any better than did our former student Ian WIlson, now Reserves Manager at Irthlingborough Lakes and Meadows, who commented (on Facebook) that “There have been terrible losses but this sort of misuse of statistics is unhelpful and misleading. It particularly undermines the ecosystem services arguments which suggest that loss of wildlife will directly affect human populations. You can’t maintain that argument and claim that we’ve lost 50% of wildlife over the last 40 years without having to explain why human populations are still so high. Conservation would be better served by more good science and less journalistic sound bites.” Well said Ian! Fifty percent of wildlife has not be lost; the statistic is actually that “the Living Planet Index (LPI), which measures more than 10,000 representative populations of mammals, birds, reptiles, amphibians and fish, has declined by 52 per cent since 1970”. Those “representative populations” are highly skewed towards large, easily counted species of vertebrates, predominantly in temperate areas, and exclude plants and invertebrates – you can download the full report here. I’m not suggesting that these statistics are anything less than worrying, but the scale of the loss of “wildlife” (in its fullest sense) is not as great as the Guardian’s report suggests.

There’s been huge concern about the disturbing Ebola outbreak in West Africa and beyond, including a statement from IUCN on the links between emergent diseases such as Ebola and loss of biodiversity. In short, deforestation allows humans to hunt animals in previously unexploited areas, increasing the likelihood that rare and novel diseases that use wild animals as a vector (such as Ebola) can pass to humans. Worrying, and yet another reason why we need to slow down, and ultimately stop, such habitat destruction.

On a happier note, my colleague Duncan McCollin had a paper entitled ‘Reconstructing long-term ecological data from annual census returns: a test for observer bias in counts of bird populations on Skokholm 1928–2002‘ published in the journal Ecological Indicators. It highlights a really nice example of an ecological monitoring scheme that, as Duncan puts it, deserves “the recognition of such long-term data for science in terms of an appropriate conservation designation”.

Finally, here’s a link to an impassioned blog post by my friend and colleague Dave Goulson from the University of Sussex. Dave is a longstanding researcher and campaigner about the adverse effects of neonicotinoid pesticides on pollinators and other biodiversity. Dave’s post originated as a letter in reply to a (misinformed and biased) opinion piece in The Times, which the newspaper saw fit not to print (freedom of the press, eh?) It’s well worth reading and sets out the scientific case for the impact of these pesticides. And if Dave’s blog is not sufficient for you, there’s also been a recent paper from Charles Godfray’s group at Oxford called “A restatement of the natural science evidence base concerning neonicotinoid insecticides and insect pollinators” which received comments and input from many scientists involved in pollinator research (myself included) as well as formal peer review. Hopefully that’s enough rigour for the sceptics.

All pollinators are equal, but some pollinators are more equal than others

8 Replies

The infamous line from George Orwell’s Animal Farm asserting that “All animals are equal, but some animals are more equal than others” nicely captures an ecological view of pollinators and their relationships with plants. “Pollinators” by definition move pollen between flowers, but not all pollinators are equally good at transferring pollen of any particular plant: some are more effective than others. I’ll illustrate this with examples from the urban garden that Karin and I are developing, which I’ve discussed before.

As you can see from that link, the garden is modest in size, but nonetheless this year it contains a significant biodiversity of edible plants that require pollinators for some or all of the fruit and seed set, including: strawberries, apples, greengages, cherries, blackcurrants, squashes, courgettes, blackberries, fennel, runner beans, french beans, passion fruit, tomatoes, raspberries, and radishes.

“Radishes?!” I hear you ask. “But they are grown for their edible swollen roots which don’t require pollination!” True, usually. But we let our radishes flower because we mainly grow them for their seed pods which, picked young, are delicious in salads and stir fries, like mustardy mange tout. They look like this:

The radish flowers are pollinated by a diversity of insects including butterflies, bees, and small flies:

These insects will vary in their effectiveness as pollinators of radish, depending on the frequency of visits, how often they move between flowers, and the amount of pollen on their bodies. This last factor is largely a function of size and hairiness (bigger, hairier insects carry more pollen as a rule), though cleanliness also plays a part: insects often groom the pollen from their bodies and, in the case of bees, may pack it into their pollen baskets where it’s not available for pollination.

The size and behaviour aspect is best illustrated by some recent photos that I took of visitors to the flowers of passion fruit (Passiflora caerulea var.). We have a large, sprawling plant growing up a fence which is currently being visited by honey bees, hoverflies, solitary bees and bumblebees. In comparison to the size of the flower and the position of the anthers (male, pollen producing parts) and stigmas (female, pollen receiving parts), the hoverflies, honey bees and solitary bees are relatively small. These two images are of honey bees (Apis mellifera):

Here’s an unidentified solitary bee:

These bees were occasionally touching the anthers, mainly with their wings, so some pollen will be moved around. But from what I observed it’s likely to be a relatively small amount in comparison to bumblebees, which are usually much larger and hairier, and don’t groom themselves as often as honey bees. Here’s a Buff-tailed bumblebee (Bombus terrestris):

They were actively collecting pollen as well as nectar. Much of this pollen is packed into the pollen baskets on the rear legs and will go back to the nest to feed the developing larvae, but some will be involved in pollination:

So it seems to be the bumblebees we have to mainly thank for the deliciously sweet-sour fruit we will enjoy later in the season. Of course to test this properly we would need to set up an experiment in which we excluded larger bumblebees from the flowers and only allowed smaller bees to forage, with appropriate experimental controls. Would make a great project if any of my students are interested! But it should give you a sense of just how complex the interactions between flowers and their pollinators are: the ecology of pollination is far from simple, despite what some would have us believe.

From Chester to Copenhagen

3 Replies

P1110838

It is 6.30am on Sunday morning but I’m wide awake and can hear the hotel in which we are staying stirring into life. Time to reflect on what has been a long and busy week, rather than the start of a long and relaxing summer holiday as some assume academics enjoy. That’s a myth: summers for many of us are at least as busy as the main teaching part of the year, though that’s not to say we don’t teach in the summer – I have final year project students to advise, and for students who did not pass first time round there’s still re-sit exams and assignments to be undertaken.

Of course I’m not complaining and the busyness is part of the fun of my job, which includes opportunities to travel, as I’ve previously described on this blog. Before any travelling this week, however, Monday was taken up listening to my PhD student Kat Harrold give a seminar about the progress of her research on pollinator mapping and habitat modelling in the Nene Valley Nature Improvement Area. This was followed by an hour’s grilling from the supervisory team and an independent colleague, as we drilled down into the research and suggested ways in which Kat could improve on the already excellent work that she’s doing. All of this is a formal part of our PhD programme and Kat aquitted herself very well indeed.

Tuesday was the start of the travelling, and was spent in Chester helping with filming for an episode of a new four-part BBC2 series provisionally called Plant Odyssey, fronted by Carol Klein, Gardener’s World presenter and Honorary Fellow of the University. The series is being produced by Oxford Scientific Films and will be broadcast in the spring. In the following scene we were making a rose perfume based on an ancient Roman recipe from the writings of Pliny the Elder.

Now, I know very little about how to make perfume, but I do know a bit about flower scents and how they attract pollinators, so my role was to act as both a foil for Carol’s scent experiment and to add some science to the mix. This is not the first filming I’ve done with Carol, having also helped out with her Science in the Garden special edition of Gardener’s World a few years ago. While looking for that last link I discovered that all three episodes of Bees, Butterflies and Blooms is also available on YouTube, which is great to see as the BBC didn’t repeat the series or produce a DVD. I was involved in the making of episode 2, which helped to kick-start the RHS’s Perfect for Pollinators plant labelling campaign. Television work is fun and brings science, and the scientists who do it, to a much wider audience.

Wednesday I prepared my talk for Friday’s lecture in Copenhagen (more of which later) and Thursday involved attending the University of Northampton’s annual postgraduate research conference. This is a highlight of the year for me as it’s an opportunity to see the breadth of postgraduate research going on across the university, something that would be impossible in a larger and more research intensive institution. I was only able to attend the first session, but that alone covered research on the research process itself; feminist cyborg literature; the legality of the World Bank’s scrutiny panel; pollinator conservation (Kat Harrold again); and the experiences of families with children who have difficulties communicating. Questions from the audience tended to be broad and non-specialist, and all the better for that: often it’s the straightforward, naive questions which test specialist knowledge.

The rest of Thursday Karin and I packed and then travelled up to Birmingham International for an early evening flight to Denmark. I’d been invited by my colleague Bo Dalsgaard to present a research seminar at the University of Copenhagen’s Center for Macroecology, Evolution and Climate. Coming from a small and very diverse department, it was great to visit such a large and specialised group of researchers, though over lunch the Center’s Director Carsten Rahbek told me that a common complaint from his staff was: “Why can’t we employ more people doing what I’m going?” Everything’s relative I suppose.

The title of my talk was “Pattern and process in pollination at large geographic scales”, which gave an overview of some of the research I’ve published over the last decade or so, framed around the following questions:

Globally, how many plant species are animal pollinated?
Are plant-pollinator interactions more ecologically specialized in the tropics?
How predictable are pollination syndromes in different parts of the world?
What are the historical and contemporary drivers of the relative importance of animal versus wind pollination? [No link here as that manuscript is currently in review!]

Quite a number of people in the Center were out doing field work or were otherwise engaged so I spoke to a modest-sized audience of some 30 people: certainly not the smallest audience I’ve ever presented to – that was three people, including the two who had invited me to give the talk!

The lecture seemed to be well received and there were some stimulating questions afterwards, though also a couple of challenging ones about statistical analysis. One of these I couldn’t answer until afterwards because I’d forgotten the details of the methods we’d used (note to self: re-read old papers before you present their findings). In answering the other I agreed with the questioner that the data could now be analysed in a more sophisticated way (future task, if I ever get the time). If Kat’s reading this, I hope she takes satisfaction in not being the only person to be asked difficult questions about their research this week!

Afterwards I chatted with Bo and Carsten about the limitations of the current and paleo-climate data sets we’ve been using in some studies, which are indeed very limited. But there are only two options. Do we work with data sets that are flawed, whilst acknowledging that any conclusions are tentative? Or wait until better data become available, which could be a decade in the future? My choice is definitely to go with the former, otherwise we’d never publish anything because there are always limitations to data used in studies of ecology and biodiversity. Personal and public honesty about such limitations, and ideas as to how they can be overcome in the future, are surely preferable to stalling research.

Later that afternoon I discussed science with two of Bo’s collaborators, Pietro Maruyama a Brazilian PhD student whom I’d met last November, and Peter, a Danish undergraduate. Both are doing excellent work on that most charismatic group of pollinators, the hummingbirds.

Friday evening I was exhausted, and Karin and I opted for dinner in the hotel restaurant and an early night, as Saturday was to be spent exploring Copenhagen. It’s a great city for wandering around, with fascinating architecture and unexpected additions to buildings, such as bronze dragons:

And parks with statues of artists and writers, such as Hans Christian Andersen:

P1110841

After a roundabout wander, via a gallery selling African tribal art (which we couldn’t afford) and a small lunch (which we could only just afford – Copenhagen’s an expensive city!) we eventually ended up at the University’s Botanical Garden, which has a superb living collection of cacti and succulents, orchids and other epiphytes, and alpine plants.

P1110846

It beautifully illustrates the huge morphological diversity encompassed within the 352,000 or so species of flowering plants, one of the many reasons why I love visiting botanical gardens: I always see something new. This included two species of bumblebees (Bombus) which I’m sure don’t occur in Britain. I’ll have to look them up when I get back: from Chester to Copenhagen and, tomorrow, back to Northampton.

Nature as gardener (Darwin’s Unrequited Isle part 5)

“These things aren’t to study. They’re to turn up very loud and say, hey, once upon a time, everything was just as easy as this”

3 Replies

The title of this brief post is a quote by Led Zeppelin frontman Robert Plant, from an interview that the BBC reported just this morning, regarding the forthcoming release of previously unheard Zeppelin material. You can read the story and hear the interview here.

Regular readers of this blog will know that I’m not averse to sprinkling musical references into my posts, and this was a great quote that seemed to chime with something else I read this morning. Over at the Small Pond Science blog, evolutionary ecologist Amy Parachnowitsch has a thought provoking post entitled “Save the bees, but maybe not this way“. I’ll let you read it for yourself, but in a nutshell Amy is concerned about the scientific legitimacy of a “Save the Bees” campaign being crowd funded by online activist network Avaaz.org.

I share this concern and it worries me that whoever is organising the campaign is exploiting the genuine desire by people to “do something for the bees” without any regard for what exactly it is that’s “being done”. It seems to me to be purely a campaign fund-raiser by people who don’t understand the issues or how science works, the message being: “These things aren’t to study. They’re to turn up very loud and say, hey, once upon a time, everything was just as easy as this”.

The organisers promise “the world’s first large scale, grass-roots supported, totally independent study of what’s killing our bees that decisively challenges the junk science of big pharma”. As Amy notes, this is hugely offensive to independent scientists who are working on bee conservation issues (such as myself). But without ever actually saying what they are going to do with the money, they’ve already had pledges of money from over 78,000 people! If only raising funds for real research was that easy!

To reiterate what I said in the comments to Amy’s post, something that really worries me is that over-emphasis on pesticides and honey bees as single issues affecting “pollinator conservation” deflects attention from other factors which are at least as important, such as habitat loss. Colleagues and I have a manuscript in preparation at the moment showing that native bee and flower-visiting wasp extinctions in Britain began in the mid-19th century and reached their highest rate during the period 1929-1959, during a time of rapid agricultural intensification (but prior to the introduction of neonicotinoid pesticides that is currently exercising many people). Loss of pollinator diversity is an issue that has deep roots.

In actual fact, although wild bee diversity is declining in the UK, overall abundance seems to be stable as some species are doing extremely well, including a new natural colonist, the Tree Bumblebee (Bombus hypnorum) which is spreading fast and is locally common. But clearly greater diversity provides us with future insurance against losses of other species.

There are positive things that can be done for pollinator populations by every citizen, beyond giving money to crappy, pseudo-scientific campaigns, as I talked about in a recent post of mine. So please don’t contribute to this Avaaz.org request, and use the money you save to buy some wild flower seeds and/or the Led Zeppelin reissues. It will make the world a better place.

Book review: “Pollination and Floral Ecology” by Pat Willmer

2 Replies

Review of “Pollination and Floral Ecology” by Pat Willmer (2011) Princeton University Press. £65. pp. 832.

Some backstory: In early 2012 I was asked by the review editor of the journal Annals of Botany to review this book, and I jumped at the chance as it’s the first major single-author overview of the field of pollination ecology for a number of years, by a well respected academic in the field. Unfortunately the review took a lot longer than I expected, in part because I was also coordinating my department’s Research Excellence Framework submission, on top of other teaching, research and admin duties, and it was taking up quite a bit of my time.

In addition I had mixed feelings about the book and wanted my review to do it justice, not be over-critical but at the same time highlight what I saw as flaws. In the words of the Fairport Convention song, Who Knows Where the Time Goes? – my review was only completed last Christmas and duly submitted. Turns out that the journal has a backlog of book reviews to publish and the editor asked that, given it’s been a couple of years since the book was published, would I mind if the review was posted on the Annals of Botany blog rather than in the printed journal. I happily agreed as it’s likely to get more readers on the blog, and said I’d also post it on my own blog. So here it is:

Any text book that tries to assess and summarise the whole of a multidisciplinary research field such as pollination ecology and floral biology is required to be four things: (1) comprehensive in its scope; (2) up to date in its coverage of the literature; (3) accurate in its assessment of the current state of the field; and (4) authoritative in the conclusions it presents.

This volume by Professor Pat Willmer of the University of St Andrews certainly ticks the first box. It’s a huge book, and covers everything relating to the evolution of flower attraction and reward systems, ecological interactions with pollinators, biochemistry, physiology, agriculture and conservation; all in 29 chapters split into three sections, with 87 pages of references. The literature extends to 2010, which is impressive for a book published in 2011 (though see my comments below about completeness of the literature). Specialist terms are highlighted in bold to direct the reader to the glossary at the back, a useful device even if there are a few inaccuracies, which I’ll mention later.

So far so good, and the author is to be congratulated on putting together such a comprehensive, not to mention timely, single-author book. It’s clearly the summation of a career devoted to studying pollinators and flowers, and the author’s passion for her subject is apparent throughout.

However when we come to points 3 and 4, things are less straightforward. There are some issues with accuracy that are troubling in a book aimed at newcomers to the field as well as established researchers. To give just a few examples:

– on p.18 we are told that asclepiads have “one stamen” (they have five); on p.169 and in the glossary that asclepiad pollinia are the pollen grains from one anther (they are the contents of half an anther); and on p.170 that the pollinaria are “glued” to pollinators (they actually clip on).

– in the glossary, tree ferns are referred to as “cycads”, an error that is repeated on p.89.

– on p.88 there is a statement suggesting that tree fern spores were dispersed by “animal fur” 300 million years ago, long before the evolution of mammals, and that this (and dispersal of spores of fungi and mosses) is the equivalent of pollination: it is not, it equates to seed dispersal.

These are troubling errors of basic botany that are forgivable in an early draft of the book (everyone makes mistakes) but not in the final published version, after it’s been read, reviewed, checked and edited. If the book goes to a second edition I hope that these (and other) mistakes will be fixed. But they do hint at a fundamental problem with a book (and a field) as large and complex as this: a single author is arguably unlikely to be able to do justice to all of the subject matter.

There are parts of the book where it is unclear (to me at least) what the author is actually saying. For example, on p.96 there is a graph which, it is suggested, demonstrates that pollination by animals is “technically uncommon when assessed in terms of the numbers of broad taxonomic groups that use it”, though the legend to the figure claims that “most orders of plants have no families” that possess wind pollination. This is confusing: what is to be concluded by someone new to the field? Is animal pollination common or rare? Likewise, on p.91 we are told that the “first angiosperms…would probably have had their pollen moved mainly by wind…”, but then on p.92 that “an element of insect pollination could be regarded as almost ancestral”. Which is correct?

There are other aspects to the book that are simply out of date; for example the linear, rather deterministic schemes set out in Figures 4.6 and 4.8 showing that Cretaceous flowers were open and radially symmetrical, and only later evolved into complex, bilateral flowers in the Tertiary, ignores fossil discoveries showing that orchids evolved in the Cretaceous (Ramírez et al., 2007). Likewise, discussion of “counterproductive” crypsis in flowers (p.124) neglects recent findings of cryptic, wasp-pollinated plants in South Africa (e.g. Shuttleworth & Johnson, 2009).

There is a theme emerging here: some of the botany that the book presents is inaccurate, confused or out-dated. Fortunately the zoological aspects of the book are much better, as one might hope from a Professor of Zoology.

The final criterion, that the book should be “authoritative in the conclusions it presents”, is however, in my view, the main weakness of this volume. The author is unhappy with recent developments in the field, particularly as they relate to community-scale assessments of plant–pollinator interactions, in terms of network analyses and predictive utility of pollination syndromes. Clearly Professor Willmer is on a mission to rebalance what she perceives as failings within some of the current trends in studying pollination. A book review is not the place for a technical dissection of the author’s arguments, which is best left to the peer-reviewed literature (though I would argue that that’s also the place to present some of the criticisms the author introduces, rather than into a text book such as this). I could focus the whole of this review on these topics because: (a) they take up a large proportion of the book, about one-third of the text pages; and (b) they are highlighted on the cover as being one of the main contributions of the book; specifically, that the author provides a critique of previous work that does not distinguish between “casual visitors and true pollinators” that can in turn result in “misleading conclusions about flower evolution and animal-flower mutualism”. Unfortunately her targets are straw men, and one – I believe quite telling – example will suffice.

On p.447 there is a criticism of the use by Waser et al. (1996) of Charles Robertson’s historical data set, and specifically that the analyses they present “…did not distinguish visitors from pollinators even though Robertson’s database did include information on this”. However Waser et al. clearly state (p.1045 of their paper) that only pollinators were included in the analyses, not all flower visitors, and that “visitation is not a synonym for pollination…non-pollinating visitors are excluded (as in Robertson 1928)” (p.1048).

Why should Professor Willmer make a statement to the contrary? Evidently she wishes to impress upon her readers that (in her opinion) there are fundamental problems in current approaches to studying pollination at a community level. But even if that were the case (and I don’t believe it is) misrepresenting previous studies to suit an argument is poor scholarship at best.

Regardless of whether some of her criticism is well founded, the author does not seem to appreciate that plant–flower visitor interaction networks are ecologically important regardless of whether or not a flower visitor acts as a pollinator. More fundamentally, true pollination networks possess similar attributes to flower visitor networks, for example a nested pattern of interactions, and arguments about level of generalisation of species are a matter of scale, not category (Ollerton et al., 2003).

At the end of her Preface, Professor Willmer reveals to us quite a lot about her personal attitude to research when she states that some readers might find her approach “too traditional” in an “era where ecological modelers [might be claimed to] have more to tell us than old-style field workers”. What the author fails to appreciate is that this is a grossly false dichotomy and that most of the pollination ecologists who have embraced new analytical methodologies for understanding plant–pollinator interactions are also “old-style field workers” with considerable experience of studying the ecology of flowers and their pollinators beyond the computer screen.

In summary this is a book that, for all its good qualities of comprehensiveness and (mostly) up to date coverage, should be read with caution: parts of it are neither as accurate nor as authorative as the field of pollination and floral ecology deserves.

LITERATURE CITED

Ollerton J, Johnson SD, Cranmer L, Kellie, S. 2003. The pollination ecology of an assemblage of grassland asclepiads in South Africa. Annals of Botany 92: 807-834.

Ramírez SR, Gravendeel B, Singer RB, Marshall CR, Pierce NE. 2007. Dating the origin of the Orchidaceae from a fossil orchid with its pollinator. Nature 448: 1042-1045.

Shuttleworth A, Johnson SD. 2009. The importance of scent and nectar filters in a specialized wasp-pollination system. Functional Ecology 23: 931-940.

Waser NM, Chittka L, Price MV, Williams N, Ollerton J. 1996. Generalization in pollination systems, and why it matters. Ecology 77: 1043-1060.

What are YOU doing for our pollinators this year? (reduce, reuse, recycle part 6)

4 Replies

Earlier this year I was asked to write a short article by my former PhD student, and still a current collaborator, Dr Sam Tarrant. Sam works for the RSPB as the CEMEX UK-funded Biodiversity Advisor, and wanted something on pollinator conservation that could be circulated in the CEMEX company’s e-newsletter. In the spirit of reworking and reusing odd bits of writing, I thought I’d post it here too.

Insects are vital for our country’s economy. Don’t believe me? Then read on….

Beneath a large black mulberry tree near the University of Northampton’s Newton Building there is a plaque that commemorates its planting “On Shakespeare Commemoration Day, 3^rd May 1916”. Despite its age this tree annually produces large crops of succulent berries, aided by the fact that wind eddies are sufficient to disperse its pollen, ensuring pollination and fruit set. Each year it’s a scramble between students, lecturers and birds, to see who can eat the most.

In contrast, the old apple trees in the grounds possess a different strategy – pollination by insects that move from flower to flower each spring. This form of pollination is both more sophisticated and less reliable than wind pollination, and is currently under considerable threat: whilst there will never be a shortage of wind currents in Britain, insect pollinators are in decline.

The apples trees are not alone in requiring insects to pollinate them, so to do other farm and garden crops, including oil seed rape, field beans, courgettes, runner beans, and strawberries and other soft fruit. It’s worth at least £440 million annually to the British economy, and most of it is done by wild bees and hoverflies, rather than managed hives of honey bees.

But all is not well with these insects in Britain – they are in decline. Although the extent of the “pollination crisis” is debated by scientists, long term records show us that these insects are under pressure: 23 species of bee and flower-visiting wasp have gone extinct since the mid 1800s, as have 18 species of butterflies. Less obviously, other species have considerably reduced in abundance so that they are now found in only a small part of their previous distribution.

There are lots of gardeners who want to “do something” for the pollinators, and keeping honey bees is often mentioned. By all means, if you wish to help the honey bees (which are suffering their own problems) then keep a hive or two. That will not, however, help our wild, native pollinators; the analogy I use is that it’s the equivalent of trying to help our declining songbirds by opening a chicken farm!

If you want to make a real difference for pollinators in your own garden, here are a few ideas:

start by planting nectar and pollen rich flowers; there’s a useful list on the Royal Horticultural Society’s website (see below).
allow plants such as clover and dandelion to flower in your lawn, bees love them.
as well as food, pollinators also need nest and egg laying sites, so you could help by allowing some of the far corners of your plot to run a little wild.
wait until late Spring to cut back hollow stemmed perennials as they are used as hibernating places by some of our bees.
allow mason bees to nest in old walls and don’t worry about them, the wall won’t fall down.
And finally, stop using pesticides!

Changing some of our gardening habits can help a group of insects on which we rely and which supports our economy in a very real way.

Further reading and information:

Bees Wasps and Ants Recording Society: http://www.bwars.com/

Bumblebee Conservation Trust: http://www.bumblebeeconservation.org.uk/

Butterfly Conservation: http://www.butterfly-conservation.org/

Hoverfly Recording Scheme: http://www.hoverfly.org.uk/

Royal Horticultural Society’s list of plants for pollinators: http://www.rhs.org.uk/Gardening/Sustainable-gardening/Plants-for-pollinators

Thank the insects for Christmas (REBLOG)

9 Replies

It’s become a tradition (ok, only for the past two years, but a tradition has to start somewhere!) for me to post a version of this festive blog entry. I’ve updated the stats for 2013. Hope you enjoy it.

Christmas! A time to relax and enjoy ourselves, to share time with family and friends, and to unwind during the cold and gloom of winter. Whatever your faith, or lack of it, Christmas should be about taking a break and reflecting on the year that has passed. We’re helped in that respect by the ceremonial seasonal trimmings: the Christmas tree, strings of flashing lights, baubles and tinsel. So while you’re kissing a loved one under the mistletoe, admiring that glossy holly wreath, or tucking into your Christmas dinner, spare a thought for the insects.

“What in Saint Nicholas’s name” you are asking ”have insects got to do with Christmas?!” Well, like the turkey, we’d be stuffed without them: they play an essential part in providing us with the things we associate with Christmas. If we had no flies, wasps, bees and other bugs acting as pollinators there’d be no berries on your mistletoe or your holly. Kissing and admiring would be a less festive affair and that’s just for starters. These insects also pollinate many of the vegetables, herbs and spices on your plate, as well as some of the forage that went to fatten your roast bird or tender joint of meat. Not to forget much of what went into the nut roast that’s feeding the vegetarian relatives.

The economic value of insect pollination in the UK was estimated by the recent National Ecosystem Assessment to be about £430 million per year. In fact this is a huge under valuation because the labour costs alone of paying people to hand pollinate those crops would run into billions of pounds. This sounds far fetched but it’s already happening to fruit crops in parts of China. The answer is to encourage wild insects, not artificially managed honey bees, because collectively the former are far more abundant, and often more effective, as pollinators. Their diversity is an insurance against losing any one species in the future. The NEA’s valuation is also too low because it only deals with commercial edible crops, and does not include those we grow in our gardens and allotments. It also does not take account of ornamental crops such as mistletoe and holly, both of which are dioecious species, which is to say that individuals are either male or female, rather than hermaphrodite as are most plants. This means that the plants cannot self pollinate and insects are absolutely vital to their reproduction and to the production of the decorative berries we so value (a holly wreath without berries is just a big spiky doughnut, in my opinion).

Whilst researching the economic value of the annual mistletoe and holly crops for this blog posting last year I had a conversation with Jonathan Briggs over at Mistletoe Matters and he told me that “the mistletoe trade in Britain is entirely unregulated and not documented in any tangible way”, and the same is true of holly. We therefore have no idea what the economic value of these non-food crops actually is. But some back-of-the-red-and-gold-Christmas-lunch-napkin calculations can at least give us an insight. Auction reports for 2013 show that on average the best quality berried holly was selling for £2.50 per kg whilst equivalent quality holly without berries sold for only 80p per kg. In other words, pollination by insects increases the value of that crop by more than 300%! Similarly the high quality mistletoe averaged £1.20 per kg, whilst the second grade stuff was only 40p per kg. And the best holly wreaths (presumably with berries!) were averaging £7.00 each.

These are wholesale prices, of course; retail cost to the customer is much greater. A decent holly wreath will set you back between £15 and £30 whilst online shopping for mistletoe is in the £5 to £20 range, depending on how much you want. The national census of 2011 shows us that there are 23.4 million households in England and Wales, plus there are 2.36 million in Scotland and 0.70 million in Northern Ireland. Let’s round it down and say there’s 26 million households in the whole of the UK. Let’s also be very conservative and estimate that only 5% of those households bought one holly wreath and some mistletoe at a total cost of £20. Multiply that by the small proportion of households buying these festive crops and you arrive at a figure of about £26.5 million! And that doesn’t include non-household use in shops, offices and businesses. So there you have it: an industry worth a few tens of millions (at least) all being ultimately supported by insects.

With pollination, timing is everything, and Jonathan also made the point that spring flowering mistletoe and holly can be important early nectar sources for insects. Therefore despite the poor summer weather in 2012, that year was a good one for mistletoe berries because the pollination happened before the heavy rains began. Despite being quite common plants, rather little research has been done on either holly or mistletoe pollination in the UK and it would make for an interesting student project. The Landscape and Biodiversity Research Group here at the University has for many years been working to understand the ecology of plants and pollinators, and how to best conserve them. In this blog I’ve referred a few times to some ongoing projects researching how the wider landscape is supporting pollinators in habitats such as country house gardens (Hilary Erenler’s PhD work which she completed this year) and urban centres (ongoing PhD work by Muzafar Hussain). There’s also the work completed a few years ago by Sam Tarrant and Lutfor Rahman on pollinator (and other) biodiversity on restored landfill sites. Plus research that’s recently started by Kat Harrold on how whole landscapes support pollinators in the Nene Valley Nature Improvement Area. This is all part of a broader programme of research into the conservation of biodiversity in our region and beyond, including our Biodiversity Index, a contribution to the Shared Enterprise Empowering Delivery (SEED) sustainability project.

Biodiversity matters and its importance to our society is being increasingly recognised by government, business and the public. So if you make one New Year’s resolution on the 31st December, let it be that you will put away your garden bug sprays for 2014 and learn to love the insects (even wasps!) who give us so much and help to support our economy in a very real way. It costs us nothing; all we need to give them is well managed, diverse, unpolluted habitats in which to live. Have a great Christmas everyone!