Monthly Archives: December 2014

Did you remember to thank the insects for Christmas?

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This year I decided not to re-post my traditional “Thank the insects for Christmas” piece, in part because I don’t want to bore the good readers of this blog with too much repetition, but also because the idea has been taken up by the Urban Pollinators Project at the University of Bristol, and developed into an infographic (on which I advised) that you can view here.  The BBC News Website used the information for a nice article called “The insects that made Christmas“.  So look back on your Christmas dinner, if you had one, and give thanks to the many invertebrates that made it happen!

The other reason for not doing a full re-post of that piece is that I was feeling worn out by a long university term that ended not with a whimper, but a stressful double-bang of publication of our pollinator extinctions paper (and the associated media interest, which I may talk about early in 2015) and the release of the results of the Research Excellence Framework, which I coordinated for my department.  We were pleased with the outcome, with over 40% of our research papers rated as “world leading” or “internationally excellent”, and most of the rest being “recognised internationally”.  For a young, mainly teaching-focused, non research-intensive institution such as the University of Northampton (which doesn’t enjoy the facilities and funding of older, larger universities), that’s an impressive result.

A final bit of news is that this blog made it onto the MySciBlog survey 2014, by Paige Brown Jarreau (Louisiana State University) who asked more than 600 science bloggers “to list up to the top three science blogs, other than their own, that they read on a regular basis”.  The initial results can be found at Figshare, and I’ve inserted network graphic below (click on it for a larger view).  The size of a node is proportional to the number of respondents who read that blog regularly and my blog is part of the green section near the top, tucked just under the dominant Dynamic Ecology.  It’s gratifying to know that other bloggers are reading this in significant numbers!

Thanks to everyone who has read my blog over the past year, particularly those who have commented on the ideas and information I’ve presented: best wishes to you all for 2015!

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Filed under Biodiversity, Ecosystem services, Pollination, University of Northampton

A Christmas vignette (re-post from 2013)

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First posted Christmas 2013, I thought it was worth re-posting as it’s as resonant this year as last.

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This afternoon I booked half a day’s leave to go into Northampton town centre to pick up some final Christmas gifts.  A crowd of shoppers in Abington Street was eager to lay their hands on the freebies being distributed by that traditional Yuletide apparition, The Coca Cola holidaysarecomingholidaysarecoming Big American Truck.  As red and shiny as Rudolf’s nose, it was pedalling its cheap brand of Christmas sentimentality to a willing audience.  

Shopping completed and daylight fading fast, I headed back to the multi-storey car park, again passing the Coca Cola queues, skirting them, determined not to be sucked in.

The car park was cold and ugly, as they tend to be.  But on the second floor, level with the bare crown of a tree that emerges from an adjacent pub garden, a mother and her young son stood.  Hands full of shopping bags, they had paused to listen to a male blackbird singing as the dusk drew in.  As I passed I heard them chatting about its song: both agreed it was beautiful.

Driving out of the car park I wound down my window: the blackbird was still singing.

I could give a very academic spin to this tale and talk about the cultural and spiritual ecosystem services that are provided by such birds, which nourish us in ways that no amount of corporate marketing ever could.  But I shan’t: it was a perfect Christmas vignette and a perfect contrast to the earlier soulless commerciality.  And that’s sufficient.

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Filed under Biodiversity, Biodiversity and culture, Birds, Ecosystem services, Urban biodiversity

Extinction of British bees and flower-visiting wasps – a new assessment of rates and causes

Extinction of species is perhaps the most fundamental assault that we as humans can inflict on the rest of the natural world.  Extinctions take a range of forms, from the loss of a whole species (such as the sad case of the St Helena Giant Earwig, recently declared extinct by the IUCN), down to extirpation of local populations.

For an island nation such as Britain, extinctions at a country level are highly significant because there is limited opportunity for species to disperse across the sea and re-colonise areas where they previously lived.  In a new research paper published this week in the journal Science we have addressed the subject of pollinator declines in the UK and asked the following questions:

1.  How many bee and flower-visiting wasp species have gone extinct in the UK?

2.  Is the rate of extinction (e.g. number of species per decade) constant or variable over time?

3.  Can we interpret any patterns in relation to broader societal changes, for example in agricultural policy, conservation strategies, etc?

The research is a collaboration between myself and University of Northampton colleagues Dr Robin Crockett and Dr Hilary Erenler, together with Mike Edwards from the Bees, Wasps & Ants Recording Society (BWARS), the c. 500,000 records of which were used in these analyses.  This is probably the most extensive data set on these insects available for any country and an important resource.

The answer to the first question is that 23 species of bees and flower-visiting wasps have gone extinct, ranging in time from the crabronid wasp Lestica clypeata (last observed in 1853) to the solitary bee Andrena lathyri (not seen since 1990).  All of these species still occur on mainland Europe, so these were country-level extinctions, not species extinctions.

The answer to questions 2 and 3 is that the rate of extinction is highly variable, and by using a novel statistical approach adapted by Robin to analyse the changing rate over time, we found that the main period of species loss followed changes to agricultural policy and practice just after the First World War.  This is much earlier than previously believed: until now it has usually been the Second World War and the subsequent Common Agricultural Policy which have been seen as the main drivers of pollinator loss.  This figure produced by Robin shows the results in detail:

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The four periods marked in red are the points where we estimate the rate of extinction changed (with 99% confidence intervals shown in pink).  The most rapid rate of extinction (shown by the solid blue piecewise regression lines and dashed 99% confidence intervals) is from the late 1920s to the late 1950s.  This, we believe, is the cumulative effect of agricultural changes precipitated and then augmented by the First and the Second World Wars, respectively.

The period of extinction from the late 19th into the early 20th centuries was probably caused by increased import of South American guano as soil fertilizer which increased grass productivity at the expense of wild flower diversity.  This reduced reliance on strict rotational cropping, including fallow periods with nectar- and pollen-rich weeds, and N-fixing legume years.  However it was the invention of the Haber Process in 1909, allowing industrial manufacture of inorganic nitrogen fertilizers for the first time, that fundamentally affected British agriculture.

The slow down of the rate of extinction from the early 1960s to the mid 1980s is not easily explained given the continued intensification of farming, encouraged by Common Agricultural Policy subsidies.  It could be due to the most sensitive species having been already lost, or because of conservation initiatives including the establishment of more nature reserves by organisations such as the Wildlife Trusts and the RSPB, habitat restoration and management by groups such as the British Trust for Conservation Volunteers, more farmers going organic, etc.  Or it could be a combination of both, and/or factors we’ve not yet thought of.

The final period of extinctions from 1986 to 1994, where the rate seems to increase, could be seen as evidence against the slowing in the rate of decline of pollinators in north west Europe found by Carvalheiro et al. (2013).  However  we need to be cautious here as there’s a large confidence interval around the calculated extinction rate.  The four extinctions between 1988-1990 could be an isolated cluster, or the start of a further period of relatively high extinction rate.  Only time will tell!

Bees, wasps and other pollinating insects are absolutely vital to the functioning of our natural ecosystems and for a great many agricultural crops.  We’ve known for some time that these insects are declining in Britain but now we can see how historical agricultural changes have caused species to become extinct. The big question is whether these extinctions have stopped or whether they will continue in the future. The species that have been lost to Britain still survive on the Continent and there is the possibility of natural re-colonisation or artificial reintroduction, both of which have occurred in recent years.  However in order for this to be successful we must restore as much natural habitat as possible within our farmland, which after all covers some 70% of the British land surface.  The irony of our findings, of course, is that pollinators are vital for agriculture, as the UK Government’s National Pollinator Strategy recognises.

Studies such as this illustrates the importance of maintaining the year-on-year effort of recording natural history data – the research simply wouldn’t have been possible without the BWARS records, which are mainly collected by amateur naturalists.

The full citation for the paper is:  Ollerton, J., Erenler, H., Edwards, M. & Crockett, R. (2014) Extinctions of aculeate pollinators in Britain and the role of large-scale agricultural changes. Science 346:1360-1362.  I’m happy to send a PDF to anyone who requests a copy for personal use. 

Notes:

1.  We define “extinction” as ≥ 20 years since the last recorded occurrence of the species in Britain, which is why the data stop at 1994.

2.  We have excluded single early records of species that cannot be verified as representing stable breeding populations.

3. Analyses were performed using the ‘segmented’ library in R (www.r-project.org)

4.  Thanks to Robin Crockett for the figure and the analyses, and Hilary Erenler and Mike Edwards for their input into the study.

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Filed under Bees, Biodiversity, Ecosystem services, Macroecology, Pollination, University of Northampton

Winter visit to Wicken Fen

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If it’s winter, it must be time for the annual second year undergraduate field trip to Wicken Fen, a yearly pilgrimage that’s been run by my colleague Dr Janet Jackson for many years now.  The purpose of the trip is to show our ecology and environmental science students an example of large-scale habitat conservation and restoration in action, at one of England’s oldest nature reserves.  I try to go along and help out when I can, though I missed it last year because of my trip to Brazil.  It was more than a fair swap, though there’s something about Wicken’s stark winter beauty that always makes for a memorable day.

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The National Trusts’s nature reserve at Wicken Fen is one of the few remaining patches of the wetland habitat that once covered most of East Anglia.  There’s little of it left (less than 1% of the original area) but large-scale, long-term initiatives such as the Great Fen project and the Wicken Fen Vision are trying to increase this by restoring the farmland surrounding the remaining patches.  This is important landscape-scale conservation because the fenland habitat is rich in biodiversity.  Wicken Fen alone is reckoned to host more than 8,300 species of macro-organisms, most of which are invertebrates, including more than a thousand each of flies and beetles.  There’s also an impressive list of birds that use the site either for breeding or over-wintering, and on our day trip we managed to see 31 species*, highlights of which were a pair of Hen Harriers, a lone hunting Barn Owl at dusk, and a huge flock of Lapwing and Golden Plover that provided a backdrop to our guided tour.

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Another great highlight which impressed both students and staff was a close encounter with some Konik Polski ponies which were curious and friendly, and yet more or less wild, as they stay out on the Fen all year round with no shelter and the minimum of human intervention.

Konic ponies

Everyone was enchanted by these hardy little horses and it was a struggle to get the students to move on with the tour!

Konic ponies with Janet

As Carol Laidlaw, conservation grazing warden at Wicken Fen explained to us, these ponies, together with the tough highland cattle, are a vital part of Wicken Fen’s ecology.  Their grazing prevents woody plants from colonising, and this, together with their physical presence in the landscape, leaving hoof marks and dung piles, opens up both small patches and larger areas for colonisation by plants.  For anyone interested in reading more about the grazing animals I can recommend Carol’s excellent article on the project.

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Although the day was cold it was not the frozen landscape we normally encounter and there were even a few plants still in flower.  It’s been a mild winter so far – how long will that continue?  If you’ve never visited Wicken Fen I can recommend it as a day trip whatever the season or weather, there’s always fascinating wildlife to see.

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*Bird list for the trip was: Collared Dove, House Sparrow, Blackbird, Kestrel, Fieldfare, Goldfinch, Cormorant, Grey Heron, Magpie, Lapwing, Golden Plover, Carrion Crow, Snipe, Hen Harrier, Wigeon, Great Tit, Blue Tit, Feral Pigeon, Starling, Wood Pigeon, Robin, Chaffinch, Wren, Shoveler, Tufted Duck, Coot, Mallard, Common Gull, Herring Gull, Jackdaw, Barn Owl.  Plus chickens being kept in the garden of one of the local cottages!

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Filed under Biodiversity, Birds, University of Northampton