The role of press freedom in protecting the environment

Ollerton et al Press freedom Figure 1

Recently I’ve been working with a couple of journalist colleagues at the University of Northampton on a short article exploring the relationship between press freedom and environmental protection in different countries.  That piece has just been published on the Democratic Audit website – here’s the link.

I think that the findings are really interesting, and timely in an age when press freedoms are being eroded and journalists physically attacked and even murdered.


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Filed under Biodiversity, Biodiversity and culture, University of Northampton

Celebrating the environmental and historical heritage of the Nene Valley

One of the great privileges of the job I have is working with individuals and organisations across all aspects of conservation and science; people who are asking the most fundamental of ecological or evolutionary questions, through to those addressing on-the-ground questions of habitat management and restoration.  One of my current roles is as a board member for Nenescape Landscape Partnership Scheme, funded by the Heritage Lottery Fund (2016-2021) and involving multiple Northamptonshire partners, with the University of Northampton acting as the Competent Authority for the financing of the scheme.  Our students and staff are also involved in various ways, volunteering their time and expertise.

Friday and Saturday this week was taken up representing the University and the Nenescape board at events that showcased Nenescape-funded projects.  First up was the East Northants Greenway project where we admired the new benches that had been installed, the clearance of rubbish along this former railway, tree planting, the All Aboard for Rushden Art Codes project, and a new mural, and chatted with local residents who seem to be very happy with the work that’s been done.  Then it was along to Rushden Transport Museum to look at the work that’s been done on the old railway goods shed.  On Saturday I was up at Ferry Meadows near Peterborough to try out the new boardwalk that has been installed and to see the restoration of Heron Meadow as a site for overwintering wild fowl and waders.  I now have temporary tattoos of pollinators…. Later in the afternoon I headed to Stanwick Lakes for a celebration of the new barn and heritage garden that’s been created as part of the Settlers of the Nene Valley project, complete with a Viking re-enactment group.  Here are some images from the two days:

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Filed under Biodiversity, Biodiversity and culture, Nene Valley NIA, Nenescape, Northants LNP, University of Northampton

What exactly is a “pollination system”?

Pollination systems

This is a post I’ve been meaning to write for some time, but have never got round to.  What’s catalysed me is an email this morning from Casper van der Kooi asking me about how I define the term “pollination system”, as he’d had some discussions about its use with his colleagues in The Netherlands.

“Pollination system” is one of those terms that seems to mean different things to different people. The way I use it, and I think the way we meant it in the 1996 paper Generalization in pollination systems and why it matters, is that the pollination system = floral phenotype + pollinators.  That is to say, the colour, shape, size, odour, rewards, etc. produced by a flower (or an inflorescence functioning as a single reproductive unit) plus the animals that effectively transfer pollen.

To me this is distinct from a “pollination syndrome” which refers only to the floral phenotype, or “pollinator guild/functional group” which refers only to the flower visitors.  However I have seen “pollination syndrome” used to include floral phenotype + pollinators.  But to my mind they are distinct things.

I have also seen other authors use “pollination system” to mean the community of plants and pollinators in an area, or as analogous to the breeding system, but neither of those are the way that I use it.  I decided to look at the history of the term on Web of Science and the earliest use on there is a paper by Levin & Berube (1972): Phlox and Colias – efficiency of a pollination system.  There were a few other papers from the same decade and all were using pollination system in the way I described above, i.e. floral phenotype + pollinators.

To look for earlier usage of pollination system I searched the Google Ngram Viewer; as you can see in the image above, I found examples of the term back as far as the 1940s in which the pollination system of grasses is referred to as being “cross pollination” (i.e. what we would now refer to as the breeding system).  There’s also texts from the 1950s referring to artificial wind pollination of date palms as a “helicopter pollination system”.

Does it matter how “pollination system” is used, or that it varies in meaning according to the author?  Probably not as long as the meaning is defined in the text.  Ecology is replete with terminology that has slightly different usage according to the researcher (“biodiversity” being an obvious example) and I don’t get a sense that this has held back the field.  Or is that too optimistic a conclusion?  Do you use the term in a different way to me?  As always, your comments are welcomed.


Filed under Biodiversity, History of science, Pollination

Auto-bee-ography – a new genre of writing?


In the post today I was pleased to find a copy of Brigit Strawbridge Howard’s first book Dancing With Bees that she had kindly signed and sent after I reviewed some of the text.  It was great timing – I’ve just finished Mark Cocker’s Our Place, a really important historical and future road map of how Britain got to its present position of denuded and declining biodiversity, and what we can do to halt and reverse it. Highly recommended for anyone interested in environmental politics and action.  So Brigit’s book will be added to the pile on my bedside table and may be next in line, though I still haven’t finished Dave Goulson’s The Garden Jungle – perhaps I will do that before I start Dancing With Bees?

And thereby lies a problem – there’s just too many interesting books to read at the moment if you are interested in the environment, or indeed even just in pollinators.  Because a new genre of writing seems to be emerging that I call “auto-bee-ography”. A number of writers are using bees to frame their memoirs and anecdotes.  Dave’s trilogy of Buzz in the Meadow, Sting in the Tale, and Bee Quest is probably the best known. Then there’s Buzz by Thor Hanson; Following the Wild Bees by Thomas Seeley; Bees-at-Law byNoël Sweeney; Keeping the Bees by Laurence Packer; Bee Time by Mark Winston; Bees Make the Best Pets by Jack Mingo; Buzz: Urban Beekeeping and the Power of the Bee
by Lisa Jean Moore and Mary Kosut; The Secrets of Bees by Michael Weiler; and The Bumblebee Flies Anyway by Kate Bradbury.

All of these books fall more-or-less into the category of auto-bee-ography, and I’m sure there are others that I’ve missed (feel free to add to the list in the comments below).  They follow a strong tradition in natural history and environmental writing of using encounters with particular groups of organisms, for example birds and plants, as a way of exploring wider themes  Which is great, the more high profile we can make all of these organisms, including pollinators, the better in my opinion*.

However there’s not enough written about the other pollinators, that does seem to be a gap in the literature.  Mike Shanahan’s Ladders to Heaven has a lot about his encounters with figs and their pollinating wasps, but that’s about it, unless I’ve missed some?  Perhaps in the future I’ll write something auto-fly-ographical called No Flies on Me.  But before that, look out for Pollinators and Pollination: nature and society which I’m currently completing for Pelagic Publishing.  It should be out in Spring 2020.

*Though not in everyone’s – I had a very interesting discussion on Twitter with some other ecologists recently about whether pollinators had too high a profile compared to organisms that perform other functional roles in ecosystems such as seed dispersers.  You can follow the thread from here:






Filed under Bees, Biodiversity, Biodiversity and culture, Book review, Pollination

“The time of the singing of birds is come” – a Nottinghamshire gravestone with a bird bath


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Yesterday Karin and I took the day off and explored an area along the Nottinghamshire/Leicestershire border with friends.  In the small village of Normanton on Soar we found a very unusual headstone in the churchyard, carved in granite and surmounted by a bird bath.  Around the bowl some lead text reads:  “The time of the singing of birds is come”

The bowl was empty when we arrived so I filled it: it’s going to be a hot weekend and the birds might appreciate it.

The headstone marks the burial place of Edward Hands and Ethel Maud Hands, presumably husband and wife; the smaller marker commemorates Derek Hands (their son?).  None had a long life; Edward was 42 when he died, Ethel 56, and Derek just 36.  The headstone was erected originally for Edward (who pre-deceased his wife by 20 years) so perhaps it was he who was keen on birds?

I’ve never seen a headstone in the form of a bird bath though I can’t believe that it’s unique: does anyone know of others?

Here’s the full grave; it was only after I took the picture that I noticed the feather.

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The text around the bird bath is from the Bible, the Song of Solomon 2:12.  The fuller version is:

“The flowers appear on the earth; the time of the singing of birds is come, and the voice of the turtle is heard in our land.”

We didn’t hear any turtles, but here were plenty of flowers around the village, including a buddleia that was smothered in very fresh looking painted lady butterflies that are likely to have been born nearby rather than migrating over from the continent:

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It was also a time of bees such as this very active feral honey bee colony in a lovely 15th century  timber framed house:


Filed under Biodiversity, Biodiversity and culture, Birds, Personal biodiversity

“Weighted” nestedness and “classical” nestedness analyses do not measure the same thing in species interaction networks

This post resulted from a question I posed on Twitter last week and hopefully summarises the issue as I see it and the results of the discussion with colleagues that followed.  Let me know if you disagree or if I have missed anything.

The use of network approaches to understanding how plants and their flower visitors interact has revolutionised the study of these and other mutualistic assemblages of species.  It’s a subject I’ve discussed on the blog before, highlighting some of the work we have published – for instance, see Plant-pollinator networks in the tropics: a new review just published and Local and regional specialization in plant–pollinator networks: a new study just published as two recent examples.

One of the recurring patterns that we see in mutualistic species networks (but not in antagonistic ones such as host-parasite and predator prey) is “nestedness”.  In a nested assemblage of species, generalists with lots of links to other species interact with other generalists and with specialists (those species which have few links to other species)Conversely, specialists tend only to link to generalists: specialist-specialist interactions are rare.  In nature, when we rank species in a network from most to least generalised, this sort of relationship looks like this:

South Africa nested

The rows are plants and the columns are pollinators, in this case from an assemblage of asclepiads and their pollinators we studied in South Africa.  A filled cell in the matrix indicates an interaction between that particular plant-pollinator combination.  It’s not perfectly nested by any means, but statistically this is not a random pattern and it comes out as nested when analysed.  There are a few ways of doing this but the most commonly used is the Nestedness metric based on Overlap and Decreasing Fill (NODF) developed by Almeida-Neto et al. (2008).

I first saw nestedness discussed in relation to plant-pollinator interactions in a presentation by Yoko Dupont of her PhD research at a SCAPE meeting in Sweden in 2001.  It was one of those “A-HA!” moments in science when the light bulb switches on and you realise that you are seeing an important new development which adds significant understanding to a field.  Yoko subsequently published her work as Structure of a plant–flower‐visitor network in the high‐altitude sub‐alpine desert of Tenerife, Canary Islands.

The nested pattern of interactions is conceptually derived from earlier work on island biogeography and species-area relationships and was initially developed to apply to interaction networks by Jordi Bascompte and colleagues in Spain and Denmark – see: The nested assembly of plant-animal mutualistic networks.

What was so exciting about this idea to me was that it provided a way to formally analyse what many of us had been observing and discussing for some time: that mutually specialised plant-pollinator interactions between species are rather rare, and that specialists tend to exploit generalists.  This makes perfect sense because specialist-specialist interactions may be more likely to go extinct, though why it does not also apply to host-parasite interactions is far from clear (and in fact the best known specialist-specialist interactions tend to derive from seed parasitism interactions such as fig-fig wasp and yucca-yucca moth relationships).

Fast forward 20 years and the plant-pollinator networks literature has exploded and our methods of analysis are much more sophisticated than they were in the late 1990s and early 2000s.  Every few months researchers are coming up with new ways in which to analyse these networks, mainly using the R environment for statistics and graphing.  Anyone entering the field would be forgiven for being bewildered as to which approaches to use: it’s bewildering enough for those of us who have been following it from the start!

One thing has been particularly bewildering me for a few years now, and that’s the introduction of “weighted” nestedness.  “Weighted” in this sense means that the abundance or interaction frequencies of the species in the network is taken into account in the analyses.  Visually it could look something like this if we code the cells in the network above to represent abundance or frequency (the darker the cell, the more abundant or frequent):

South Africa nested weighted

I’ve just mocked up the network above, it’s not the actual data.  But quite often networks look like this when we weight them: generalist interactions and/or species tend to be more frequent than specialist.  So far, so obvious.  But here’s the thing: networks that are statistically significantly nested when analysed by NODF tend to be not significantly nested when analysed by a new set of weighted metrics such as wNODF or WINE – see the documentation for the bipartite package for details.   And I don’t understand why.  Or rather I don’t understand why we should be using weights in an analysis of nestedness which is, at its heart, an analysis of presence-absence.  Species are either there or they are not, they are either interacting or they are not.  Their frequency or abundance is immaterial to whether a network is nested.  Indeed, assessing frequency of interactions in plant-pollinator networks is fraught with difficulties because (a) there are so many ways in which to do it; and (b) interactions between plants and pollinators in a community can vary HUGELY between years and across the geographical ranges of the species involved.

This should concern the interaction network community because recently I’ve had reviewers and co-authors saying things like: “don’t analyse for nestedness using NODF because wNODF/WINE is The Latest Thing, use that instead”.  But as far as I and the colleagues who commented on Twitter can tell, nestedness and weighted nestedness are different concepts and are not inter-changeable.  Indeed, many of us are struggling to really define exactly what weighted nestedness analyses are actually measuring.  I can define nestedness in simple terms as a verbal concept, without using the word “nested”, as you saw above.  I can’t do that with weighted nestedness, and I have yet to encounter anyone who can.

So the consensus from the Twitter discussion seems to be that:

  • for any study we should use only those analyses that are relevant to the questions we are asking rather than simply running every available analysis because there are lots to choose from.
  • weighted interaction networks that include abundance or frequency are not necessarily superior to binary presence-absence networks.  Again, it depends on the question being asked.
  • we should not treat weighted nestedness as an upgraded or superior version of classical nestedness.  If you are interested in nestedness, use a binary analysis like NODF.

My thanks to the colleagues who contributed to the Twitter discussion:  Nacho Bartomeus, Pedro Jordano, Pedro Luna, Marco Mello, Chris Moore, Timothée Poisot, and Kit Prendergast.  If you want to follow the Twitter discussion, start here:



Filed under Apocynaceae, Biodiversity, Rewilding

Websites about bees and other pollinators that are not in English – can you add to my list?

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The book I’m currently completing is going to have a list of useful websites with information about bees and other pollinators, and pollination itself, that are not written in English.  Following a shout-out on Twitter I’ve come up with the following list – can anyone add to it?  There’s a lot of countries/languages missing.  Please respond in the comments section or send me an email:












French Canadian:










With thanks to everyone on Twitter who responded.


Filed under Bees, Biodiversity, Pollination

Bees and beer in London: an urban beekeeping experience

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One of our Christmas presents from Karin’s son (my stepson) Oli and his girlfriend Kate was an “experience” – a chance to spend half a day with an urban beekeeping collective in London called Bee Urban.  The group has a partnership with Hiver Beer which uses its honey in its brewing, and we were promised a tasting session.  Bees, beer, London – what’s not to like?  Karin and I finally made the trip down to Kennington yesterday and it was a really enjoyable experience, highly recommended.  I know a little bit about beekeeping but it was great to see a small professional apiary at work and to take part in a hive examination.  It certainly deepened my appreciation of these remarkable insects.  It also made me think about having a hive or two when I retire and have the time to devote to the hobby – beekeeping is not to be entered into lightly!  However there’s a time and a place for honeybees: in the wrong setting they can be a conservation problem by negatively affecting plant reproduction, out-competing native bees and passing on their diseases to bumblebees.

Bee Urban, however, is also doing its bit for wild bees in London by providing opportunities, such as drilled logs, for cavity nesting species.  We saw lots of evidence that leaf-cutting bees (Megachile spp.) and those that seal their nests with mud (various genera) were taking advantage of these nesting sites.

Interestingly, one of the other attendees said at the outset that she was very scared of bees.  I asked her afterwards if seeing beekeeping up close had helped and she said it had.  Perhaps this is something that you could do with any insectophobes in your life?

The beer was great, by the way, also highly recommended!

Below are some pictures from the day.  Thanks to Lena and Barnaby for hosting us and making it such an enjoyable experience.

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When she saw this picture, Karin likened it to cult devotees attending a ritual – “All Hail the Bee Goddess!”:

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Karin and I get up close and personal with the bees:

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A real highlight of the day – seeing the queen of this hive (marked in red):

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Yum! – :

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Drilled logs being used by leaf-cutting bees (Megachile spp.):

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Filed under Bees, Biodiversity, Honey bees, Urban biodiversity

A Climate Change Tourist in America

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Following on from my recent post about A train ride through American climate change, my wife Karin has extended this and written a great piece called A Climate Change Tourist in America for Medium.

It’s a really beautifully observed and thoughtful piece of writing that weaves together themes that I would never have considered dealing with: aspects of life, love, tourism, poverty, suicide and desperation, all linked by climate change.  It’s only a 10 minute read: do yourself a favour and take a look.

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Filed under Biodiversity, Climate change

Last year’s mother, this year’s child: cinnabar moths in the garden

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Most summers we have a small colony of cinnabar moths (Tyria jacobaeae) reproducing in the garden.  The garish yellow-and-black caterpillars feed on species of ragwort and we leave a patch of common ragwort (Jacobaea vulgaris) to grow in the lawn.  The caterpillars eat for a few weeks, virtually destroy the ragwort, and in the process accumulate alkaloids from the host plant into their bodies.  This renders them toxic in much the same way as monarch butterflies accumulate toxins from their Asclepias food plants – see my recent post about the Monarchs and Milkweeds workshop.  Hence the stripes to warn birds of their unpalatability.

Ragwort is a much-maligned plant, hated by those with horses and livestock, and subject to a largely hysterical campaign of eradication – see here for example.   However John Clare clearly appreciated its virtues in a poem dedicated to the plant:

Ragwort, thou humble flower with tattered leaves
I love to see thee come & litter gold,
What time the summer binds her russet sheaves;
Decking rude spots in beauties manifold,
That without thee were dreary to behold.

The full text of the poem can be found here.

Once they have fed their fill, the caterpillars dig themselves into the soil to spend twelve months or so underground as pupae, before emerging as gorgeous adult moths, advertising their toxicity with a different colour scheme.

The adults live for a few weeks at most, during which time they feed on nectar, mate, lay eggs and die.  This (unposed) photograph that I snapped on my phone in the garden yesterday just about sums it up: an exhausted mother has laid her last batch of eggs then died, while a nearby young caterpillar munches away on the ragwort.  And so the generations pass.

Cinnabar caterpillars on ragwort


Filed under Biodiversity, Gardens, Moths, Urban biodiversity