Tag Archives: ecosystem services

How good is the evidence base for pollinator declines? A comment on the recent Ghazoul and Goulson Science correspondence

In a recent issue of the journal Science, Dave Goulson and colleagues presented a review entitled “Bee declines driven by combined stress from parasites, pesticides, and lack of flowers”.  This stimulated Jaboury Ghazoul to submit a letter to Science criticising the Goulson et al. paper from a number of perspectives, but particularly the paucity of the evidence base for pollinator declines. Dave and his co-authors robustly responded to that letter, as you might imagine. In some respects this was an unsatisfactory exchange, however, as the focus was largely on agricultural pollinators, rather than pollinators of all plants (including the majority non-cultivated species) and I think that (perhaps with more space?) Dave could have outlined the evidence in more depth.

The most striking statement in Jaboury’s letter was that the “evidence for pollinator declines is almost entirely confined to honeybees and bumblebees in Europe and North America”.

Now, even given the fact that Jaboury was possibly referring specifically to agricultural pollinators, that is a very extreme statement to make. Underlying it is the suggestion that global concerns about declining pollinator biodiversity (a subject I’ve discussed repeatedly on this blog) is underpinned by a taxonomically and geographically thin evidence base. Is that really true? I don’t believe so and I think it’s worth presenting a brief overview of the evidence, not least because Dave’s review and the resulting correspondence is pay-walled at the Science site (though if you Google the titles you might, just might, find copies posted on the web…)

Let me state from the outset that I have considerable respect for both Jaboury and Dave, as individuals and as scientists. I’ve known Dave since we were postgrads together in the early 1990s, and have had occasional contact with Jaboury through conferences and via email. So this isn’t meant to be a criticism of either of them.  But I do believe that the evidence for pollinator declines is considerably more robust than Jaboury acknowledges, and even more wide ranging than Dave and colleagues describe in their response (though in fairness, most of the bee evidence was cited in their original review).

Here’s a summary of where I see the evidence base at the moment; it’s not meant to be a full review, by any means, but rather to give a flavour of the taxonomic and geographical breadth and depth of the evidence as it currently stands:

Wild bees (including bumblebees, and solitary and primitively eusocial bees) – significant reduction of abundance and diversity at local, regional and country-levels documented in Britain (Biesmeijer et al. 2006, Ollerton et al. 2014), Holland (Biesmeijer et al. 2006), Europe as a whole (Kosier et al. 2007, the recent IUCN Red List by Nieto et al 2014), North America (Grixti et al. 2007, Cameron et al. 2011, Burkle et al. 2013), South America (Morales et al. 2013; Schmid-Hempel et al. 2013), China and Japan (Xie et al. 2008; Williams et al. 2009; Matsumura et al. 2004; Inoue et al. 2008), and South Africa (Pauw 2007).

Honey bees – colony declines documented in Europe and North America (see reviews by NRC 2007, Potts et al. 2010) and evidence that global demand for honey bee pollination services is outstripping supply (Aizen and Harder 2009).

Hoverflies (Syrphidae) – diversity declines documented in Holland and Britain (Biesmeijer et al. 2006).

Butterflies and moths – diversity and abundance of Lepidoptera has declined in the UK (Gonzalez-Megias et al. 2008, Fox 2013), whilst in North America some 50 species are IUCN criteria Red Listed and there is particular concern about the iconic Monarch butterfly.  Likewise a significant fraction of butterflies in other parts of the world are of conservation concern, e.g. Southern Africa, Australia, and Europe.

Flower-visiting wasps – reduction in country-level diversity in Britain (Ollerton et al. 2014).

Birds and mammals – the major vertebrate pollinators have recently been assessed at a global level by Regan et al. (2015) using IUCN Red List criteria.  They concluded that: “overall, pollinating bird and mammal species are deteriorating in status, with more species moving toward extinction than away from it. On average, 2.5 species per year have moved one Red List category toward extinction in recent decades, representing a substantial increase in the extinction risk across this set of species”.

Of course a number of the studies cited above have shown that some species are doing better than others and a proportion of the taxa they have assessed are stable or even increasing in abundance (including managed honey bee colonies in some parts of the world). But the current evidence base, as I see it, is pointing towards significant declines in pollinator abundance and diversity at multiple spatial scales across all regions that have so-far been assessed with any rigour, for a wide range of taxa.

I’m happy to receive comments on this topic, particularly pointing me to major sources of evidence that I’ve not covered, or if you disagree with my conclusions.


Aizen and Harder (2009) The global stock of domesticated honeybees is growing slower than agricultural demand for pollination. Current Biology 19: 915–918.

Biesmeijer et al. (2006) Parallel declines in pollinators and insect-pollinated plants in Britain and the Netherlands. Science 313: 351–354.

Burkle et al. (2013) Plant-pollinator interactions over 120 years: Loss of species, co-occurrence, and function. Science 339, 1611–161.

Cameron et al. (2011) Patterns of widespread decline in North American bumble bees. Proc. Natl. Acad. Sci. U.S.A. 108: 662–667.

Fox (2013) The decline of moths in Great Britain: a review of possible causes. Insect Conservation and Diversity 6: 5–19.

Gonzalez-Megias, A. et al. (2008) Changes in the composition of British butterfly assemblages over two decades. Global Change Biology, 14: 1464-1474.

Grixti (2009) Decline of bumble bees (Bombus) in the North American Midwest. Biol. Conserv. 142, 75–84 (2009).

Inoue et al. (2008). Displacement of Japanese native bumblebees by the recently introduced Bombus terrestris (L.) (Hymenoptera: Apidae). J. Insect Conserv. 12: 135–146.

Kosior (2007) The decline of the bumble bees and cuckoo bees (Hymenoptera: Apidae: Bombini) of Western and Central Europe. Oryx 41, 79–88.

Matsumura et al. (2004) Invasion status and potential ecological impacts of an invasive alien bumblebee, Bombus terrestris L. (Hymenoptera: Apidae) naturalized in Southern Hokkaido, Japan. Glob. Environ. Res. 8, 51–66.

National Resource Council (2007) Status of Pollinators in North America.  National Academies Press, Washington, DC.

Nieto et al. (2014) European Red List of Bees.  Publication Office of the European Union.

Ollerton et al. (2014) Extinction of aculeate pollinators in Britain and the role of large-scale agricultural changes.  Science 346: 1360-1362.

Pauw (2007) Collapse of a pollination web in small conservation areas. Ecology 88: 1759-1769.

Potts et al. (2010) Declines of managed honey bees and beekeepers in Europe. Journal of Apicultural Research 49: 15–22.

Regan et al. (2015) Global Trends in the Status of Bird and Mammal Pollinators. Conservation Letters DOI: 10.1111/conl.12162

Schmid-Hempel et al. (2013) The invasion of southern South America by imported bumblebees and associated parasites. Journal of Animal Ecology 83: 823–837.

Williams et al. (2009) The bumblebees of Sichuan (Hymenoptera: Apidae, Bombini). Syst. Biodivers. 7: 101–189.

Xie et al. (2008) The effect of grazing on bumblebees in the high rangelands of the eastern Tibetan Plateau of Sichuan. Journal of Insect Conservation 12: 695–703 (2008).



Filed under Bees, Biodiversity, Birds, Butterflies, Honey bees, Hoverflies, Pollination

The most important book you’ll read this year: What Nature Does for Britain by Tony Juniper


Being on holiday should be about getting away from the pressures of work and the daily routine, and relaxing with an easy novel or some magazines, turning off your brain and recharging ready for a return to reality. So what am I doing writing a book review in a sun-flooded apartment in Nice on France’s Cote d’Azur? A good question that is answered by the fact that this is a book that has been engaging me since I bought it at the airport on the way out. I’d known for some time that What Nature Does for Britain by Tony Juniper was about to be published as I’d received an invitation to the book launch in Cambridge in February. It was an invitation precipitated by the small contribution I’d made to the research for the book, when I was happy to provide some facts and figures on pollinator importance and decline in Britain. Unfortunately I missed the launch due to a prior engagement, and a poorly stocked WH Smith at Luton Airport was my first opportunity to buy a copy.

Tony Juniper is well known for his environmental writing and broadcasting so I had an idea that the book would be readable and interesting. What I wasn’t prepared for, however, was just how good the book actually is, and that it’s the most important book you could read this year. Let me rephrase that: it’s the most important book that our politicians, business leaders, bankers and economists could read this year. In fact individuals with any leverage to influence government policies and business strategies should be made to sit down and read this book. But for anyone with an interest in the future of this country (and indeed of the planet) this really is a book worth reading. And, if you are British, preferably read it before the General Election in May.

Over the course of nine chapters, Juniper looks at how nature (broadly defined and including geology and physical processes, as well as biodiversity) underpins our society through its positive contributions to food production, water resources, flood mitigation, energy security, and our physical and mental health. At the end of each chapter Juniper sets out a series of manifestos that he challenges the government of the next five years to adopt and develop. Whichever party/ies form the government come the May election, its MPs need to rise to this challenge. And whichever parties are in opposition, it’s important that they read them too because they should understand where and how the government can get it right and get it wrong.

One of the refreshing things for me was how holistic and connected are the scenarios Juniper develops as he tours Britain to find case studies of where people and organisations are getting it right, working WITH nature, not against it. It’s easy for those of us working in particular fields, as academics or practitioners, to become over-focused on one’s own specialism: for me that would be obsessing about biodiversity, for others it could be energy generation or the economics of farming or infrastructure investment or wastes management. What this book does brilliantly is to bring together all of these elements, and more, and weave them into a single, seamless narrative. For example, large offshore wind farms generate renewable energy AND contribute to reducing CO2 emissions AND create marine nature reserves for sea life AND thereby boost regional fish stocks AND create jobs on the local mainland AND provide investment opportunities for banks and pension schemes AND develop new, exportable technologies. Yes, there may be downsides and Juniper doesn’t shy away from discussing these, for example bird collisions with turbines. But it ought to be possible to minimise these negatives, such as with appropriate design and siting strategies.

Although I was aware of many of the broad arguments presented in this book, it’s been a revelation to see the details set out so clearly and the linkages made so effectively, and with rigour: my word there’s an impressive amount of research on show here. I mentioned that I was consulted, but Juniper and his researcher Lucy McRobert have talked wide and deep with academics, conservationists, business leaders, civil servants, and other experts. The acknowledgements section runs to more than five pages and I counted over 100 names of individuals who were thanked for their contributions. Presumably everyone who was quoted was given the chance to comment on what was being written, as I was.   The sources for the information presented are provided on Juniper’s website (http://www.tonyjuniper.com/). This is a thorough book, all the more impressive because it had to be researched and written quickly in order to be published, and read, prior to the election.

Juniper’s vision of a future Britain is one in which we can have it all: economic security, functioning ecosystems, endless energy, jobs aplenty, and solutions to our most pressing environmental problems, including future effects of climate change. Clearly he’s an optimist. And that’s refreshing in a country where pessimism and cynicism seems to be the plat du jour (sorry, been eating in too many over-priced French restaurants).  If he isn’t right then the worst that will have happened will be that we have engaged in a series of experiments with our social, natural and economic capital that are no worse, and could be a lot better, than some of the experiments that have been foisted upon us by a series of government and private business strategies. But my gut feeling (supported by the evidence) is that he’s right and that this book provides us with a road map towards a virtuous ecological circle with society at its centre.

The sad thing is that the people who really ought to be reading this book, and who would gain most from its vision, are those politicians, business leaders and economists who are least likely to open its pages because either they’ve “heard it all before”, and disagree, or because the momentum of their vested interests and entrenched views leaves no opportunity to redirect the course on which they are travelling.

Although the focus is on the United Kingdom, the proposals that Juniper sets out could apply to any country and the book be renamed “What Nature Does For _____” [insert country of choice].  In truth the issues presented, and their broad solutions, are global. So, this is the most important book you could read this year, wherever you live.  Buy a copy, read it (on holiday, in bed, while commuting, or wherever) and pass it on to the person you know who is least likely to buy it for themselves. Or send it to your local MP.  That’s what I will be doing in the days following the election.


Filed under Biodiversity, Book review, Ecosystem services

Whisht! lads, haad yor gobs, an’ Aa’ll tell ye aall an aaful story

River Wear in the 1980s

Every other Thursday I try to make it to the 6pm seminar organised by the Media, English and Culture department of the School of The Arts.  The seminars take place in the building adjacent to the one in which I work; they feature a diverse mix of internal and external speakers; and wine is always served.

Invariably I’m the only scientist in a room full of staff and postgrads with research and teaching interests as varied as 19th Century Gothic literature, Elizabethan playwrights, the history of the BBC’s Radiophonic Workshop and the scientific romances of HG Wells.  So the wine helps to imbue a cosy sense of oneness with my fellow academics and by the second glass I’ve convinced myself that I can contribute something meaningful to the discussion which follows.  (One day I’ll have to record those conversations and listen to them sober…..)

The seminar this week was by Dr Jon Mackley, a specialist in the literature of the early Medieval and “Dark Age” periods.  Jon talked about the writing he’s been doing aimed at understanding the lost pantheon of gods worshipped by our Anglo Saxon ancestors, and their fates as feast days and rituals were absorbed into British Christian culture.  This replacement of deities put me in mind of Neil Gaiman’s brilliant novel American Gods, but that’s by the by.

What has this got to do with biodiversity, you ask?  Bear with me…..

Conversation afterwards got onto dragon-hero myths and (fortified by some cheap red) I brought up the story of the Lambton Worm.  This legend originates from County Durham, the part of England in which I grew up, and so has always been a part of my personal culture.  My dad often sang the first few lines of the 19th Century  song when I was young and in turn I’d occasionally sing it to my kids when they were very small, in a broad Durham dialect:

Whisht! lads, haad yor gobs,
An’ Aa’ll tell ye aall an aaful story,
Whisht! lads, haad yor gobs,
An’ Aa’ll tel ye ‘boot the worm.

(Wikipedia provides a useful translation of the song for anyone born south of Darlington)

When I was thinking about the legend afterwards it struck me that there were some interesting metaphors regarding biodiversity and ecosystem services contained within it, beyond the culturally important “mythical biodiversity” of such creatures as dragons, unicorns and griffins.

The story of the Lambton Worm begins with young Sir John Lambton fishing in the River Wear:

One Sunda morn young Lambton went
A-fishing in the Wear;
An’ catched a fish upon he’s heuk
He thowt leuk’t vary queer.

Exploitation of wild fish stocks has always been an important provisioning ecosystem service for human societies in a local context, with Sunday fishermen such as John Lambton taking the occasional fish for their family; and at a national level, providing significant amounts of protein for the human food chain.  Global fish stocks are beyond the level at which they can be sustainability exploited, however, and a scandalous proportion of what is currently netted is thrown back into the sea, often dead, as “bycatch“.   The “fish” that Lambton caught was in fact a juvenile dragon (or “worm”) which looked so strange (and presumably inedible) to the young knight that he disposed of it:

But whatt’n a kind ov fish it was
Young Lambton cudden’t tell-
He waddn’t fash te carry’d hyem,
So he hoyed it doon a well

John Lambton throwing the worm into a well could be a metaphor for the way in which our society so often gets rid of the things that we produce and that we don’t want, with no real thought for its fate.  As a kid growing up in the 1970s close to the banks of the very same River Wear where John Lambton fished the Worm, I well remember the stream of turds, condoms, tampons and filth slicks that the river was expected to absorb and to transport into the North Sea.  Later I worked for a while in the local Vaux Brewery which flushed its untreated waste water in vast volumes into the Wear.  By then no one was bothering to fish the river.  In the 1980s new sewage treatment works were built to deal with the effluent of what was at that time the largest town in Britain. Slowly the water quality of the River Wear improved until it is now considered by the Environment Agency to be “one of the most improved rivers in England“.  A river which John Lambton would perhaps now recognise.

Alongside the quality of the water, the quality of life of people who live by or visit the Wear has also improved as the river’s ability to sustain cultural ecosystem services related to work, tourism and leisure has increased.  Which brings us back to the department of Media, English and Culture.  What is a muddy boots ecologist with interests in the biodiversity of species interactions doing sitting in on their seminars on a Thursday evening?  Beyond the fact that they are always entertaining and informative (and they serve wine), it’s the opportunities these seminars provide to draw parallels and create metaphors which relate to my own area of expertise which fascinates me.  Making such connections and spinning these stories is something my brain does without me asking it and I find them useful for understanding not just the complexity of the science I deal with, but also the environmental challenges facing humanity.  As a species we cannot get away from our evolutionary and ecological roots within the totality of biodiversity of planet Earth (a topic which I’ll return to in future blogs) and that is reflected in the cultural biodiversity of ideas and research topics that a university such as Northampton sustains.


Filed under Biodiversity and culture, Ecosystem services