Category Archives: Pollination

Seven things that I learned at the SCAPE 2018 meeting in Ireland

SCAPE 2018 group photo

The 32nd meeting of the Scandinavian Association for Pollination Ecology took place last week, and from Thursday through to Sunday 87 researchers from around the world met to discuss their latest findings.  For the first time the conference was held outside of Scandinavia, at Avon Rí, Blessington in Ireland.  As always it was a friendly and stimulating meeting, and a great opportunity to catch up with old friends and colleagues, and make new ones.

Here’s a link to the full programme with the abstracts.  I gave a talk about our recent work on the evolution of pollination systems in the plant family Apocynaceae which seemed to go down well enough and generated some discussion later in the bar and over breakfast.  The quality of the research and the standard of the presentations was very high and I don’t intend to single out individuals, but I did learn some things during the meeting that I wanted to highlight:

  • Some bird pollinated penstemons produce scent volatiles, even if we can’t detect them (Amy Parachnowitsch, University of New Brunswick).  Relates to this post of mine from earlier in the year on how hummingbirds have a sense of smell.
  • Staying with the theme of dispelling bird pollination myths – many of the supposedly sunbird-pollinated species of Aloe in southern Africa are in fact pollinated by non-specialist passerines such as bulbuls (Steve Johnson, University of KwaZulu-Natal).
  • There’s a data set on plant-pollinator interactions from the far north of Finland from the end of the 19th century and this area is being re-surveyed to assess changes between then and now (Leana Zoller, Martin Luther University Halle-Wittenberg).
  • Farmers who grow watermelons in Tanzania can improve their yields by encouraging more pollinators in their fields; the yields are better than adding fertliser or irrigating the crop (Thomas Sawe, Norwegian University of Life Sciences).
  • A weevil was introduced into Indonesia in the 1980s to improve yields of oil palm by increasing the rate of pollination (Lynn Jørgensen, University of Oslo).
  • There’s strong evidence that the current distributions of plants with specialised pollination systems in southern Africa are constrained by the environmental niche, and thus the distribution, of their pollinators (Karl Duffy, University of Naples).
  • Mobile saunas are a thing!  I took a photo of one (below) just to prove it.  Thanks to Dara Stanley and Jane Stout for organising that, and the rest of this brilliant conference!  Hope to see you all next year in Lund.

There was a lot more tweeting going on at SCAPE this year and you can see comments and images by searching Twitter for #SCAPE2018

If you attended SCAPE, what did you learn?  What surprised or interested you?  Please comment below.

SCAPE 2018 sauna

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Pollinator availability, mating system and variation in flower morphology in a tropical savanna tree – a new, open-access study

Curatella image by Pedro Lorenzo

Widespread plant species can encounter a variety of different pollinators across their distributional range.  This in turn can result in local adaptation of flowers to particular pollinators, or to an absence of pollinators that results in adaptations for more self pollination.   A newly published study by one of my former PhD students, André Rodrigo Rech in Brazil, has looked at this in the widespread South American savanna tree Curatella americana.  André studied 10 populations separated in space by thousands of kilometres, in cerrado vegetation, one of the most threatened habitat types in Brazil.  Here’s the abstract:

Widely distributed organisms face different ecological scenarios throughout their range, which can potentially lead to micro-evolutionary differentiation at specific localities. Mating systems of animal pollinated plants are supposed to evolve in response to the availability of local pollinators, with consequent changes in flower morphology. We tested the relationship among pollination , mating system, and flower morphology over a large spatial scale in Brazilian savannas using the tree Curatella americana (Dilleniaceae). We compared fruit set with and without pollinators in the field, and analyzed pollen tube growth from self- and cross-pollinated flowers in different populations. Populations with higher natural fruit set also had lower fruit set in bagged flowers, suggesting stronger barriers to self-fertilization. Furthermore, higher levels of autogamy in field experiments were associated with more pollen tubes reaching ovules in self-pollinated flowers. Morphometric studies of floral and leaf traits indicate closer-set reproductive organs, larger stigmas and smaller anthers in populations with more autogamy. We show that the spatial variation in mating system, flower morphology and pollination previously described for herbs also applies to long-lived, perennial tropical trees, thus reemphasizing that mating systems are a population-based attribute that vary according to the ecological scenario where the plants occur

Here’s the full citation with a link to the paper which is open access:

Rech, A.R., Ré Jorge, L., Ollerton, J. & Sazima, M. (2018) Pollinator availability, mating system and variation in flower morphology in a tropical savannah tree. Acta Botanica Brasilica (in press)

The illustration of Curatella americana  and its pollinators is by Pedro Lorenzo.

This paper is a contribution to a special issue of Acta Botanica Brasilica dedicated to floral biology and pollination biology in Brazil It’s all open access and if you follow that link you can download the papers.

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Filed under Bees, Biodiversity, Biogeography, Brazil, Evolution, Pollination

Is there really a “battle for the soul of biodiversity” going on at IPBES? UPDATED x 2

Carved demon

No.  But perhaps I should give some context to both question and answer…

The Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) describes itself as “the intergovernmental body which assesses the state of biodiversity and of the ecosystem services it provides to society, in response to requests from decision makers”.   Sounds a little dry, I agree, but in fact IPBES is the most exciting and innovative international environmental body to have emerged in recent years.  Exciting because its remit is specifically to assess how society is affecting global biodiversity in toto, but also its value to humans.  Innovative because it’s a broad church that is trying to bring together the knowledge and expertise of both natural and social scientists, practitioners, indigenous peoples, and stakeholders of all kinds. This broad approach is something which some other international bodies have not, traditionally, been so keen to adopt.

IPBES has its critics who see it as superfluous in that its mission overlaps too much with that of organisations such as the Convention on Biological Diversity, the Ecosystem Services Partnership, and the United Nations Environment Programme.  However I certainly think that there’s room for such an organisation.  We need as many voices as possible shouting about how important these issues are, at all levels of society, from the work of local conservation volunteers and the People’s Walk for Wildlife upwards to the highest levels of international governance.  So I’m a supporter of what IPBES is trying to do; perhaps I’m biased but I was especially impressed by the fact that the first major output of IPBES was a badly needed Assessment Report on Pollinators, Pollination and Food Production for which I acted as an expert peer reviewer over its two iterations.  I’ve written posts about this a couple of times – see for example this one.

In recent weeks, however, there’s been some reports of in-fighting within IPBES, and between IPBES and other organisations, that science journalists have seen as being a major war of ideas.  It culminated in Nature publishing a piece entitled “The battle for the soul of biodiversity“, backed up by an editorial suggesting that “the global body for biodiversity science and policy must heal rifts“.

The crux of the perceived disagreements centre on terminology and concepts as much as anything, and specifically the notion of ‘ecosystem services’ versus ‘nature’s contributions to people”.  These seem to me to be saying much the same thing using different words, and I have to say that I was shocked when I read those articles and wondered what the hell was going on: was IPBES really falling apart before it had even managed to firmly establish itself (remember it only launched in 2013)?  Or was this just journalistic hyperbole of the kind that serves no real purpose other than to increase sales and page views?

I have no inside track to IPBES’s workings so I kept an eye on developments.  I was delighted, therefore, to see the 19th September issue of Nature publish four letters from IPBES insiders and experts from other organisations.  All of these, plus the articles I linked to above, are open access.

The first letter is from Jasper Montana of Sheffield University pointing out that “ideas need time to mature” and that “debates are grist to the mill of innovation for environmental governance”.  In other words, IPBES is a young organisation and the sorts of terminology being used are far from mature: terms such as “ecosystem services” and “natural capital” are at most a few decades old.  Clearly there is an urgency in building governance systems that can effectively conserve biodiversity, but debates around the best terms to use will not hinder that process.

The second letter from Bernardo Strassburg in Brazil entitled “honour guidelines that reconcile world views” pointed out that IPBES’s own guide to such concepts notes that the ecosystem services approach is just one of several, all perfectly valid, ways of viewing the relationships between people and nature, and of seeing people as part of nature.

The next letter is from IPBES chair Sir Bob Watson assuring us that “squabbles don’t obscure the bigger picture” and that a diversity of opinions and ideas is one of IPBES’s strengths.  It’s worth noting here that the original model for IPBES was the IPCC (Intergovernmental Panel on Climate Change) which has in the past been criticised for not allowing a diversity of opinions among contributors to its reports.  You can’t please all the people all of the time, and clearly not Nature journalists….

Finally Rudolf de Groot, chair of the Ecosystem Services Partnership, plus colleagues Pavan Sukhdev & Mark Gough, argued that “sparring makes us strong” and write the most critical of the four letters, stating that they “strongly object to the tone and content” of the original article.  They assure us that the Ecosystem Services Partnership and IPBES are not in competition and that there is mutual respect for different opinions and concepts.  Furthermore “both organizations…stand united against biodiversity loss and ecosystem degradation…. Irrespective of the terminology used, our community is undivided in our knowledge that we fundamentally depend on nature in countless ways.”

So there you have it.  The Nature article and editorial were, in my opinion and those of the letter writers, over the top, exaggerating debates and disagreements that, whilst certainly real, do not endanger IPBES nor its mission.  I urge you to read the original articles then the letters, and make up your own mind.  Comments welcome as always.

UPDATE 1:  Just after I tweeted this post the Natural Capital Coalition added it to the bottom of a tweet thread that they had started when the original articles were published.  I confess that I missed these first time round but the thread adds extra detail to why the articles were misleading.  Well worth reading – here’s the start of the thread:

 

UPDATE 2:  It seems Nature is happy to continue the exchange of views following the article; the current issue of the journal contains another letter (once again open access), this time from Jim Harris (Cranfield University) and Janne S. Kotiah (University of Jyväskylä, Finland) pointing out that “the debate around which framework to use to value biodiversity could stem from the relatively recent coining and adoption of the concept of nature’s contribution to people (NCP).  Google Scholar returns only 19 hits for NCP and nearly 100,000 for ecosystem services, mainly because the latter has been in use for much longer“.

They go on to say (as all the correspondents on this article have) that they see no reason why the two worldviews of NCP and ecosystem services are irreconcilable. NCP seems new and different because it’s unfamiliar jargon   All of this reminded me of one of my first posts on this blog – “Business and biodiversity: oil and water?” which documented an event that I attended in London called “Biodiversity & ecosystem services: new collaboration opportunities for academics with businesses” .  It’s worth quoting what I said with regard to jargon within the field:

“In the workshop I attended there was some discussion as to whether technical language such as “biodiversity”, “natural capital” and “ecosystem services” (which one contributor referred to as “eco-babble”) deters senior business managers from engaging with nature conservation. I pointed out that words and phrases such as “email”, “internet” and “world wide web” were not so very long ago similarly considered to be technical jargon but are now part of our every day language.”

I still stand by this: technical language is only a barrier to engagement if people do not take the time to understand the jargon.  And jargon can become everyday language very swiftly.

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Hornets are pollinators too!

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This morning I spent a very pleasant couple of hours walking around the farm that’s at the heart of the Warner Edwards Gin Distillery, in Harrington just north of Northampton.  We are setting up some collaborations around conservation and sustainability between the university and Warner Edwards.  The first of these involves surveys of their farm by one of our final year undergraduates, Ellie West, to assess pollinator diversity and abundance, and opportunities for habitat enhancement on the farm.

One of the highlights of this morning’s visit was seeing this gorgeous hornet (Vespa crabro) taking nectar from common ivy (Hedera helix).  I think that she’s a queen stocking up on energy prior to hibernating.  But just look at how much pollen she’s carrying!  There’s every chance that she’s a very effective pollinator of ivy, which is a key nectar resource at this time of year.  It’s such an important plant in other ways too: ivy binds the landscape physically and ecologically, in ways few other native plants do.  Pollination by insects such as hornets (and hundreds of other species) results in berries that are eaten by birds and mammals, whilst the branches and dense, evergreen canopy provides nesting sites for birds and shelter for over wintering insects.

Hornets and ivy: two of my favourite native British species.

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Filed under Biodiversity, Birds, Mammals, Pollination, University of Northampton, Wasps

There ain’t no b(ee) in Starbucks

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I do love a road trip.  Karin and I are just back from a drive too and from her homeland of Denmark, via ferry from Harwich to Hook of Holland, in order to pick up a porcelain dinner service that belonged to her grandparents.  It was a great trip and I hope to put up some photos from that shortly.  But before then I thought I’d write a short post about a key element of any good road trip:  coffee.

If I drive for two hours or so I have to take a break and top up with at least a coffee, possibly also a snack, certainly lunch at the appropriate time.  Last Friday, en route to Harwich, we stopped off at a motorway service station that had a Starbucks.  Whilst waiting for my coffee (Americano, no milk, thank you very much) I noticed that there was quite a lot of text on the walls all about where and how coffee grows, its cultivation and harvesting, and so forth.  Being the sort of ecologist who is interested in how plants flower and set fruit I focused on the relevant text (see the photo above).  It’s a little indistinct but, in essence, this is what it says:

“Coffee plants flower once a year…..the flowers are jasmine scented….and then some magic happens….and nine months later you get coffee fruit”

Okay, I made up the bit about “magic” but, seriously, that’s what is implied by this text: that by some hocus pocus, coffee flowers turn into the coffee fruit that contain the beans.  No mention made of the fact that pollinators (mainly wild and managed bees) are important in this process.  Although coffee can self pollinate (which is fairly magical I suppose) without the pollinators we would have much less coffee of poorer quality.

In my recent review of pollinator diversity and conservation I did some back-of-the-envelope calculations of coffee production to illustrate the dependence of modern human society on animal pollination. Here’s what I wrote:

“Coffee is pollinated by a range of wild insects (mainly bees) and managed honeybees (Ngo et al. 2011), is second only to oil in terms of its value as a commodity, and supports millions of subsistence farmers. Global coffee production in 2016 amounted to 151.624 million bags, each weighing 60kg (International Coffee Organisation 2017). One coffee bean is the product of a single fertilisation event following the deposition of at least one pollen grain on a flower’s stigma. The mean weight of a single coffee bean is about 0.1g which means there are approximately 600,000 beans in a 60kg bag. The total number of coffee beans produced in 2016 is therefore 151.624 million bags multiplied by 600,000 beans per bag, which equals 90,974,400,000,000, or >90 trillion coffee beans. However coffee is on average 50% self pollinating (Klein et al. 2003) and a single bee visit may pollinate both ovules in each coffee flower, so we can divide that figure by four: nonetheless global coffee production requires at least 22 trillion pollinator visits to flowers. Clearly the global coffee market is supported by many billions of bees that require semi-natural habitat as well as coffee plantations in order to survive”.

I don’t want to pick on Starbucks, it just so happens that that’s where we stopped, and I have certainly seen similar displays in Costa, for instance, with again no mention of bees.  Apparently Starbucks et al. don’t want to acknowledge the role of these bees in supporting their (very lucrative) industry, at least not in the cafes themselves.  If you Google “Starbucks pollinators” then you find some information online about how the company values bees, etc. etc.  But come on coffee sellers, you’re better than this, let the public know in the places where the public goes!  If you need advice from an expert, someone to write some text for you, I’m more than happy to act as a consultant.

References

International Coffee Organisation. 2017. Coffee production statistics for 2016. http://www.ico.org/prices/po-production.pdf Accessed 20th June 2017

Klein AM, Steffan-Dewenter I, Tscharntke T. 2003. Fruit set of highland coffee increases with the diversity of pollinating bees. Proc. R. Soc. B. 270: 955–961

Ngo HT, Mojica AC, Packer L. 2007. Coffee plant – pollinator interactions: a review. Can. J. Zool. 89:647–660

 

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Filed under Bees, Biodiversity, Ecosystem services, Honey bees, Pollination

The evolution of pollination systems in one of the largest plant families: a new study just published – download it for free

Figure 1 JUNE revision

Interactions between flowering plants and the animals that pollinate them are known to be responsible for part of the tremendous diversity of the angiosperms, currently thought to number at least 350,000 species.  But the diversity of different types of pollination system (bird, bee, moth, fly, etc.) is unknown for most large, related groups of plants (what systematists term “clades”) such as families and subfamilies.  In addition we know little about how these interactions with pollinators have evolved over time and in different parts of the world.  Only a handful of groups of flowering plants have been studied with respect to questions such as:

How much do we currently know about the diversity of pollination systems in large clades?

How is that diversity partitioned between the smaller clades (e.g. subfamilies, tribes, genera) of a family, and what are the evolutionary transitions between the major groups of pollinators?

Do these pollination systems vary biogeographically across the clade’s range?

These sorts of questions have been addressed for the massive, globally distributed Apocynaceae (one of the top 10 or 11 largest angiosperm families with more than 5,300 species) in a study just published using a new database of pollinators of the family.  What’s more, the work is open access and anyone can download a copy for free.  Here’s the citation with a link to the paper:

Ollerton, J., Liede-Schumann, S., Endress, M E., Meve, U. et al. [75 authors in all] (2018) The diversity and evolution of pollination systems in large plant clades: Apocynaceae as a case study. Annals of Botany (in press)

In this study we have shown that (among other things):

  • The family is characterised by an enormous diversity of pollination systems involving almost all of the major pollen vectors and some that are nearly unique to the Apocynaceae.
  • Earlier diverging clades have a narrower range of pollination systems than those that evolved later.
  • Transitions from one type of pollination system to another are evolutionarily constrained, and rarely or never occur, whereas others have taken place much more often, e.g. between wasp and beetle pollination.
  • There is significant convergent evolution of pollination systems, especially fly and moth pollination, by geographically and phylogenetically distinct clades.

You’ll notice that there are 75 (!) authors on this paper.  That’s because we’ve pulled together a huge amount of previously unpublished data and used some state of the art analyses to produce this work.  It was a monumental effort, especially considering that my colleague Sigrid Liede-Schumann and I only decided to push ahead with this project about a year ago when we chatted at the International Botanical Congress that I posted about at the timeIn truth however the origins of this paper go back over 20 years to 1997 when when Sigrid and I published a study of what was then known about pollination systems in the Asclepiadaceae (the asclepiads).

In that paper we said that the research “is intended to be ongoing…[we]…hope to re-review asclepiad pollination within the next decade”.  At the time I didn’t think it would actually take more than 20 years!  However over that period a lot has changed.  For one thing the Asclepiadaceae no longer exists, broken up and subsumed within a much larger Apocynaceae.  Also, I’ve done a lot of work in the field and in the herbarium on some of the smaller groups within the family, such as CeropegiaOthers, including many of my co-authors, have also been working on different groups in various parts of the world.  Finally the level of sophistication of the analyses we are now able to do has increased beyond recognition compared to what we could achieve in the mid-1990s.  All of this means that now is the right time to produce this study.

Having said all of that, this is still a work in progress.  Our Pollinators of Apocynaceae Database contains a sample of just over 10% of the species in the family.  So lots more data on plant-pollinator interactions needs to be collected before we say we fully understand how pollination systems have evolved in this most remarkable family.  I’d be happy to talk with anyone who is interested in the family and being involved in future data collection.

The database will be freely available to anyone who wants to use it – lots more can be done with this information and, once again, I’m happy to chat with potential collaborators.

I was recently interviewed about the study, and about plant-pollinator interactions and the Apocynaceae more generally, for the In Defense of Plants podcast – here’s a link to that interview.

Finally, I’d like to express my sincerest thanks to my co-authors on this study – I really couldn’t have done it without you guys!

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British phenological records indicate high diversity and extinction rates among late-summer-flying pollinators – a recently published study

Balfour et al Figure 1

Natural history records of plant flowering and pollinator foraging, much of them collected by well informed amateurs, have huge scientific importance. One of the values of such records to ecology is that it allows us to document where these species occur in space and when they are active in time. This can be done at a range of spatial and temporal scales, but large-scale patterns (for example at a country level) are, I think, especially useful because they provide scientific evidence that can inform national conservation strategies.

During 2017 I collaborated with a young early career researcher at the University of Sussex, Dr Nick Balfour, on an analysis of the phenologies of British pollinators and insect pollinated plants.  That study was recently published (see citation below) and I think that the results are fascinating.

Nick did most of the leg work on this, which involved assessing more than one million records that document the activity times of aculeate wasps, bees, butterflies and hoverflies held in the databases by three of the UK’s main insect recording organisations, the Bees, Wasps and Ants Recording Society (BWARS), the UK Butterfly Monitoring Scheme (UKBMS) and the Hoverfly Recording Scheme (HRS).  Information on flowering times was taken from a standard British flora (Clapham et al. 1990 – Flora of the British Isles. Cambridge University Press).

As well as looking at annual flight periods and flowering trends for these organisms we also focused on pollinator and plant species that were endangered or extinct. Here are some headline results and thoughts on what the work shows:

  • About two-thirds (62%) of pollinator species peak in their flight times in the late summer (July and August), though there was some variation between the different groups – see the figure from the paper above).  Particularly noticeable was the double peak of the bees, with the first peak denoting the activity of many early-emerging solitary bees, such as species of the genus Andrena, whilst the second peak is other solitary bees plus of course the bumblebees which by that time have built up their colonies.
  • A rather fixed phenological pattern with respect to different types of plants was also apparent, which I was not expecting at all: insect pollinated trees tend to flower first, followed by shrubs, then herbaceous species (again, refer to the figure above). This might be because larger plants such as trees and shrubs can store more resources from the previous year that will give them a head start in flowering the following year, but that idea needs testing.
  • Putting those first two points together, what it means is that trees tend to be pollinated by those earlier emerging bees and hoverflies, whereas the herbs are mainly pollinated by species that are active later.
  • When looking at the extinct and endangered pollinators, the large majority of them (83%) were species with a peak flight times in the late summer, a much larger proportion than would be expected given that 62% of all species are active at that time. However this was mainly influenced by extinct bee species and the same pattern was not observed in other groups.
  • The obvious explanation for that last point is that historical changes in land use have led to a dramatic reduction in late summer flowering herbaceous species and the subsequent loss of floral resources has been highly detrimental to those bees. But intriguingly no such pattern was apparent for the endangered pollinators and clearly there are complex reasons why pollinators should become rare or extinct, a point that I have discussed previously on the blog.
  • The lack of late summer flowering resources for pollinators is a contentious issue however as plant conservation groups have in the past recommend that meadows and road verges are cut in late summer to maximise plant species richness.  Mowing road verges once or twice a year certainly benefits plant diversity, as this recent review by Jakobsson et al. (2018) demonstrates.  But there’s very little data available that assesses how timing of cutting can affect pollinators.  The only study that I know of (and if I’ve missed any, please let me know) that has considered this is the PhD work of one of my former students, Dr Sam Tarrant who looked at pollinators and plants on restored landfill sites compared to nearby nature reserves.  In a paper that we published in the journal Restoration Ecology in 2012 we showed that on restored landfill sites the abundance of pollinators in autumn surveys (conducted September-October) was just as high as for summer surveys.  On nature reserves, which are routinely cut from mid-July onward, this was not the case.

Here’s the full citation of Nick’s study with a link to the publisher’s website, and a copy of the abstract is below.  If anyone wants a PDF, drop me a line:

Balfour, N., Ollerton, J., Castellanos, M.C., Ratnieks, F.L.W. (2018) British phenological records indicate high diversity and extinction rates among late-summer-flying pollinators. Biological Conservation 222: 278-283

Abstract:

The long-term decline of wild and managed insect pollinators is a threat to both agricultural output and biodiversity, and has been linked to decreasing floral resources. Further insight into the temporal relationships of pollinators and their flowering partners is required to inform conservation efforts. Here we examined the
phenology of British: (i) pollinator activity; (ii) insect-pollinated plant flowering; and (iii) extinct and endangered pollinator and plant species. Over 1 million records were collated from the historical databases of three British insect monitoring organisations, a global biodiversity database and an authoritative text covering the national flora. Almost two-thirds (62%) of pollinator species have peak flight observations during late-summer
(July and August). This was the case across three of the groups studied: aculeate wasps (71% of species), bees (60%), and butterflies (72%), the exception being hoverflies (49%). When species geographical range (a proxy for abundance) was accounted for, a clear late-summer peak was clear across all groups. By contrast, there is marked temporal partitioning in the flowering of the major plant groups: insect-pollinated tree species blossoming predominantly during May (74%), shrubs in June (69%), and herbs in July (83%). There was a positive correlation between the number of pollinator species on the wing and the richness of both flowering insect pollinated herbs and trees/shrubs species, per calendar month. In addition, significantly greater extinctions occurred in late-summer-flying pollinator species than expected (83% of extinct species vs. 62% of all species). This trend was driven primarily by bee extinctions (80% vs. 60%) and was not apparent in other groups. We contend that this is principally due to declines in late-summer resource supplies, which are almost entirely provisioned by herbs, a consequence of historical land-use change. We hypothesize that the seasonality of interspecific competition and the blooming of trees and mass-flowering crops may have partially buffered spring flying pollinators from the impacts of historical change.

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Filed under Bees, Biodiversity, Butterflies, Hoverflies, Macroecology, Pollination, Wasps

Pollinators, landscape and friends: our recent trip to the Danish island of Sejerø

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This is not the first time I’ve written about the beautiful Danish island of Sejerø – see my post “Why do bumblebees follow ferries?“.  It’s home to our friends Pia and Stephen Valentine (Stephen is the very talented artist who produced the fabulous study of waxwings that Karin commissioned for my birthday last year).  Earlier this month we traveled over to stay with them and to explore some more of the island.  Here are some photos and thoughts from that trip.

Despite the hot, dry weather that northern Europe has been experiencing recently there were pollinators aplenty.  Thistles and knapweeds (both groups from the daisy family Asteraceae) are well known to be drought tolerant and attract a lot of insect interest.  This is a Pantaloon Bee (Dasypoda sp.)  If it was Britain I’d say that it was D. hirtipes, but there are other species on the continent so I can’t be sure.  These bees are well named: the “pantaloons” are found only on the females and are used to collect pollen, especially from Asteraceae.

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I believe that this is the male of this species; note the absence of the pollen-collecting hairs on the rear legs and the yellow face, typical of many male bees:

The flower heads of the knapweeds were highly sought after; on this one, two different bumblebees (Bombus spp.) were competing with two Silver Y moths (Autographa gamma):

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Sometimes the bumblebees got an inflorescence to themselves, though the photobombing Silver Ys were never far away:

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It’s been a good year for the Silver Y, large numbers have migrated northwards from southern Europe and we’ve had lots in our garden too.  On Sejerø they were everywhere, on all kinds of plants: 

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The butterfly is one of the Blues (Lycaenidae), possibly Common Blue (Polyommatus icarus), but again this being Denmark they may have other species that I’m not familiar with.  Note the Silver Y photobombing once more…:

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Wild carrot (Daucus carota) was common on the island and always attracts a wide range of flies, wasps and beetles:

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Close to home we found a huge cherry tree laden with the fruits of pollination and collected a couple of kilos for Stephen to make into jam.  Stoning them was messy but fun and a nice opportunity to sit and chat about nature and people:

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I was very impressed with Stephen’s up-cycled general purpose baskets, made from plastic containers he finds on the beach, wire, and lengths of old hosepipe:

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Along the shore another edible plant, Sea Kale (Crambe maritima) was attracting a lot of attention from white butterflies (Pieridae) whose caterpillars feed on this and other members of the cabbage family (Brassicaceae):

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I tried a piece of raw leaf; it tasted ok, salty and a little bitter.  Apparently it’s very nice if you blanch the young leaves.  It’s a distinctive and impressive component of the beach flora:

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Amidst the greens, buffs and browns of the beach landscape we encountered the occasional scarlet of a patch of poppies (Papaver sp.):

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Everywhere on the island we saw evidence of the link between life on land and in the sea, and the cycles and processes upon which that life depends.  Sand martins (Riparia riparia – an apt name – “riparian” refers to the interface between land and water) are common and their nest excavations speed up the return of sediments back to the sea:

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Favoured rocks have been used by gulls and other sea birds for generations, their guano helping to enrich these coastal waters and fueling the primary production of seaweeds and diatoms, which in turn feed other shore life:

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Evidence of human activities was never far away, though, concrete and steel blending with nature:

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Wheat fields merging with the sky:

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Thanks to Pia and Stephen, and of course Zenja, for making this such a wonderful trip and allowing us to join them in exploring their home island:

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Filed under Bees, Biodiversity, Birds, Butterflies, Moths, Pollination

Academic job interviews: don’t feel obliged to do everything you said you’d do

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Last month I cleared out my office in preparation for our move to the University of Northampton’s new Waterside Campus.  Going through files I’d not opened in decades was a cathartic and occasionally emotional experience.  In one file I came across a box of OHP transparencies from the presentation I gave at my job interview in 1995!  (For younger readers, OHPs were just like PowerPoint, but you carried them around in a box….)

Anyway, the presentation (see photo above) at what was then Nene College of Higher Education set out what my research plans were going to be if I was offered the job. It’s interesting to look back on these research themes and consider whether I did actually do what I said I was going to do (go to my Publications page for details of the papers I’m referring to):

Flowering phenology” – This was a large part of my PhD, which I had completed two years earlier.  At Northampton I did a bit of work,  including a big meta analysis with Mexican colleagues Miguel Munguia-Rosas and Victor Parra-Tabla, but nothing further, though I do have a lot of unpublished data that one day may see the light of, err, day….

Pollination systems in the Asclepiadaceae” – I’ve done a lot of work on this plant family, including field work in South America and Africa, particularly with my German colleague Sigrid Liede-Schumann.  However Asclepiadaceae no longer exists as a separate family (it’s now a subfamily of Apocynaceae).  I have a large paper in press at the moment which assesses the diversity of pollination systems in the Apocynaceae; more on that when it’s published.

Specialisation and generalisation in pollination systems” – yes, done lots on this too, including contributing to the Waser et al. (1996) Ecology paper that’s now racked up >1550 citations, plus assessing latitudinal trends in specialisation.  Still a major focus of my research, it’s an area where there are lots of questions still to be answered.

Reproductive output [in plants]” – very little done since my doctoral work, though questions of annual variation in reproductive allocation were a big part of my PhD.  Has fallen by the wayside rather.

Seed predation” – ditto – it was a major component of my PhD and I published a couple of things but then hardly touched the topic.  A shame in some ways as I still think it’s a fascinating topic.

Pollinator behaviour” – I’ve done some work, mainly on birds and bees rather than the butterfly model system I proposed at the time, which was to work with Dave Goulson on a follow-up of a paper we published on floral constancy in Small Skipper butterflies.  This field has moved on hugely though, with some extremely sophisticated work being done with captive bumblebee colonies for instance.

Overall I think I’ve worked on about 50% of what I said I would do, which I’m more than comfortable with.  Because I’ve also done a whole bunch of stuff I never mentioned at interview, including work on pollinator conservation and interaction network analyses, both of which were hardly thought about in 1995.  There’s also research on the history of science that I was thinking about in the early 90s but which I didn’t present as a major research theme.

The moral of this story for anyone preparing for a job interview for an academic position is: Don’t think that you have to do all of the research that you say you’re going to do in the presentation.  Opportunities come and go, and interests wax and wane.  What is currently seen as exciting research may well, in 10 years time, be seen as old hat or a dead end, or have evolved in ways that provide you with fewer opportunities to contribute.  Prepare to be flexible, but don’t lie about your intentions.  In fact, as recently highlighted on the Dynamic Ecology blog, don’t lie about any aspect of getting an academic job!

One other thing: be realistic.  In retrospect I was too ambitious in the range of areas in which I wanted to do research, though they were all linked.  But over the course of 23 years it’s impossible to say how your research career will develop.  I’m looking forward to the next 23…. 🙂

 

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Hunting the Chequered Skipper: an encounter with England’s latest species reintroduction project

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If you have been following recent conservation news on social media you’ll know that this week was an important one for invertebrates.  The Chequered Skipper, a butterfly last seen in England in 1976, has been reintroduced to the country as part of the Back From the Brink initiative.  The Chequered Skipper project is led by Butterfly Conservation and a team travelled to a site in Belgium earlier in the week where about 40 skippers were captured.  These insects were transported back to the UK where they were held overnight in mesh cages at a secret location in order to acclimatise them, then released into the wild.  The release was filmed as part of next week’s BBC Springwatch series – look out for it.

The exact location of the reintroduction is secret.  However I can tell you that it’s occurred in the Rockingham Forest area of north Northamptonshire, in habitat that (over the past couple of years) has been managed specifically for this reintroduction, in order to create a network of sites across which the species could disperse in the future.  This area was the last stronghold of the species in England prior to its extirpation.  No one knows why it went extinct here, but hung on and did well in Scotland, but it may relate to climate: 1976, as many of the middle-aged will remember, was a very hot, dry summer, and this butterfly likes it warm and humid.

Yesterday I had the privilege of seeing this reintroduction first hand when I visited the site with my colleague Dr Duncan McCollin.  Duncan and I are supervising a PhD student, Jamie Wildman, along with Prof. Tom Brereton, Head of Monitoring at Butterfly Conservation (BC), and the University of Northampton’s Visiting Professor in Conservation Science.  Jamie’s project will focus on understanding the habitat requirements for Chequered Skipper, and monitoring the success of the reintroduction.  I’m also hoping that it might be possible for Jamie to assess the role of this species as a pollinator of the plants it visits.  Butterflies as pollinators is a very under-researched area.

Here’s a shot of the Four Mus-skipper-teers* just before we set off to help BC volunteers to locate the skippers and record their behaviour:

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The day started unpromisingly.  It was cool and overcast, and little was flying except some hardy Common Carder Bees.  But around lunchtime things began to warm up and gradually the sun broke through and we started to see flying Lepidoptera that we excitedly chased, only to be disappointed by yet another Mother Shipton or Silver Y.  But no skippers.

As we encountered some of the BC volunteers who were also tracking the insects we were told that we had “just missed one” or that they “saw one down that ride, we marked the spot”.  One volunteer wanted to show me a photo of a Chequered Skipper that he’d just taken “so I could get my eye in”.  I politely refused; I wanted to see the real thing and didn’t want to jinx it with a digital preview.

Finally, our efforts were rewarded and we found the first skipper of several we later encountered.  The image at the head of this post is that butterfly, a sight that has not been seen in England in more than 40 years.  An exciting and privileged encounter.  The county Butterfly Recorder, David James (on the right in this next shot), is ecstatic that the reintroduction has occurred “on his patch” but also nervous at the responsibility it represents:

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Later we spent time helping Jamie follow a female skipper who was showing egg-laying behaviour, moving slowly for short distances along a shrubby edge, occasionally nectaring on Bugle, and diving deep into the vegetation to (we hope) oviposit on grass leaves:

 

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Although I’ve over-cropped this next image of the skipper on Bugle, I thought I’d leave it as I like the different textures and patterns, and the slightly blurry ambience:

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The primary aim of Butterfly Conservation’s project is to return a small part of England’s lost biological heritage.  But it’s about more than just the Chequered Skipper.  It’s also about understanding how managing a network of sites for this flagship species can benefit other organisms.  The wide woodland rides that have been created are packed with plant species, amongst them at least five grasses that could be used as caterpillar food sources for the skippers, plus more than 20 nectar sources were flowering that they (and other flower visiting insects) could use.  Those other insects were plentiful too: over the day I spotted five species of bumblebees, several different day flying moths, lots of Dark-edged Bee Flies, and a few different solitary bees and syrphids flies.  We heard calling cuckoos, and four different warblers: chiffchaffs, garden warbler, whitethroats, and blackcaps.  Red kites (another incredibly successful species reintroduction) floated overhead skimming the treetops as they their cried to one another.

Rockingham Forest is a lovely part of Northamptonshire, well worth a visit.  The Chequered Skipper will be a wonderful addition to its biodiversity.  Of course there are no guarantees that the reintroduction part of the project will be a success, but if it isn’t it won’t be because of a lack of commitment from the people involved.  If the population does become established then in the future the location will be made public and butterfly enthusiasts will be able to come and pay homage to one of the few butterflies with a pub named after it.

 

*You get the puns you deserve on this blog…..

 

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Filed under Bees, Biodiversity, Birds, Butterflies, Pollination, University of Northampton