Category Archives: Ecosystem services

Something for the weekend #4

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The latest in a regular series of posts to biodiversity-related* items that have caught my attention during the week:

 

  • It’s been a good week for birds: Jerdon’s babbler, a species thought to have been extinct for over 70 years, has been rediscovered in Myanmar, whilst the Blue-bearded helmetcrest, a hummingbird not seen for 69 years, has recently been photographed in Colombia.

 

 

  • Related to this, prominent ecologist Charley Krebs asks why physical sciences take the largest share of science budgets, given the importance (and urgency) of global environmental problems.  Charley’s text books have long been required reading on our undergraduate degrees, including his latest The Ecological World View.

 

 

 

 

  • Finally and close to home, the Northampton Greyfriars Bus Station, widely regarded as one of the ugliest buildings in Britain, was demolished with a set of controlled explosions.  What’s that got to do with biodiversity, I hear you ask?  Well the area of green space visible as a still before the video starts, and shown later at 0:45 and 1:15, was one of the field sites used by my PhD student Muzafar Hussain during his surveys of urban solitary bees, which I’ve talked about previously, e.g. here and here.   That patch of green, a rather neglected area of urban grassland with some scattered trees, was home to at least 17 species of bees.  Will they survive the demolition?  Hopefully, though the future redevelopment of the area may result in their loss.  But that’s been happening to urban bee populations for centuries, and they are adaptable and mobile.  I’ll talk more about Muzafar’s work in a post in the near future as the first manuscript from his PhD research has been accepted for publication.

 

Feel free to recommend links that have caught your eye.

*Disclaimer: may sometimes contain non-biodiversity-related links.

What Einstein didn’t say about bees – UPDATE – May 2021

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It’s more than 6 years (!) since I wrote this post. Over that period I’ve been asked many times about the Einstein bee quote and I’ve always replied that it’s made up, and that further more, Einstein was a physicist: he had no interest in bees!

Turns out, that’s not quite correct. There’s still no evidence that Einstein stated the infamous bee quote; however he does seem to have had an interest in bees. A newly-discovered letter from the great man mentions his admiration of the work of Karl von Frisch, whose research on the honey bee ‘waggle dance’ earned him a Nobel Prize. There’s a couple of news stories online about this: here’s one from Cosmos, and another from The Conversation. The original paper discussing the letter, by Adrian Dyer and colleagues, can be viewed here.

So I will have to moderate my response in the future, but it doesn’t change the big picture: Einstein never said it!

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In the 100th anniversary year since Albert Einstein published the paper on his General Theory of Relativity, it’s saddening to think that one of the things that he will be best remembered for is something he did not say.  There are various versions of it, but they all amount to the same thing:

“If the bee disappeared off the surface of the globe, then man would have only four years of life left. No more bees, no more pollination, no more plants, no more animals, no more man.”

This statement could be dissected and disproved in numerous ways:  for example, there’s over 20,000 species of bees, so what is “the bee”?  Plus most of our crops are not bee (or even insect) pollinated, they are wind pollinated grasses such as wheat and rice.  Etc. etc.

But what is particularly annoying about it is – EINSTEIN NEVER SAID IT!  As far as anyone is aware he had no interest in bees whatsoever and the original source was a Canadian beekeepers’ journal in the 1940s.

It’s even more annoying that, despite the fact that we’ve known the statement is both factually incorrect and not by the great man, documentary film makers and journalists are STILL using it to support their work.  The latest example I’ve seen is this documentary, the poster of which is shown above.

Rant over: back to reading paperwork for a meeting this afternoon.

UPDATE:  I’d forgotten that Tom Breeze at University of Reading posted a fuller account of Einstein’s (non) quote last year – here’s the link.

Something for the weekend #2

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The second in a regular series of posts to biodiversity-related* items that have caught my attention during the week**.

 

 

  • If you’d like to help raise money for bird conservation projects, please consider sponsoring Northants County Bird Recorder Mike Alibone’s team in the Champions of the Flyway event

 

 

 

 

 

 

  • Finally, if you’re the only person on the planet who has not seen a weasel riding on the back of a woodpecker, would you like to?  Of course you would!
*Disclaimer: may sometimes contain non-biodiversity-related links.
**Feel free to recommend links that have caught your eye.

Something for the weekend #1

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Two of my favourite blogs, Dynamic Ecology and Small Pond Science, both produce end-of-week compilations of links to interesting items on the web.  On the basis that plagiarism imitation is the sincerest form of flattery, I thought I’d follow suit with a regular series of posts to biodiversity-related* items that have caught my attention during the week**.  This is the first one.

 

  • In an article in the Times Higher, John Warren and colleagues discuss their concern about the decline in graduates with species identification skills.  They raise some valid points that echo worries that others have raised in the past, but I question their assertion that “each year there are fewer than 10 UK graduates who are proficient enough in field identification skills to be employable”.  I’d like to see some evidence to back that up.
  • Mr Spock has died; I’ve always loved Star Trek and Leonard Nimoy’s passing is sad news.  But he lived long, and he prospered, and we can’t ask more from life than that.
  • Tropical deforestation may have actually accelerated, not decreased, according to a new study.  But Brazil is faring better than other countries.
*Disclaimer: may sometimes contain non-biodiversity-related links.
**Feel free to recommend links that have caught your eye.

Garden chickens and biodiversity – some thoughts

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Keeping chickens as a hobby is very popular at the moment and many gardeners are finding space for a few chooks in their own patch.  It’s been particularly trendy amongst urban gardeners, ourselves included: we have a run with 6 hens that make us self sufficient in eggs and chicken shit (the latter a vital addition to our soil’s fertility).  They are also fascinating, relaxing animals to watch as they go about their chickeny business of scratching, pecking, clucking, and dust bathing.  They are intelligent, social, inquisitive birds, that I’d recommend to anyone who has the space to accommodate a decent sized run and (importantly) the time to look after them.

There are plenty of magazines, books and websites offering advice on keeping hens on a small scale.  One of the most active and interesting blogs is The Garden Smallholder which generally has some good advice and ideas.  Back in November, however, a post about preparing a new kitchen garden caught my attention, specifically the fact that the writer’s chickens were let out onto the plot and that:

“Chickens are great at scratching and turning over soil with their enthusiastic feet, and excellent pest control too”

Let’s think about that last point, that chickens provide “excellent pest control”.  It’s a statement that I’ve seen repeated many times in books and articles, and it usually doesn’t solicit any comments.  But the logic behind it is that hens can differentiate between “pests” and “non-pests” in a garden, that they will gobble up the slugs and cutworms, leaving behind the worms, beetles, spiders, and other beneficial (or neutral) invertebrates.  This is nonsense, of course: chickens will eat anything they find and do not differentiate between the different elements of soil biodiversity*.

For this reason we don’t allow our hens to free range on our vegetable patch: we want to keep the soil’s fauna intact, allowing the earthworms to aerate and turn over the soil, let the beetles eat the slugs, give ground-nesting bees some space in which to live, and so forth.  A few weeks of digging with chickens present would destroy all of that.

The vast majority of invertebrates that live in the soil are not pests and a significant  proportion are certainly good for our gardens (particularly the earthworms and carnivorous beetles).  Allowing your chickens to feed freely on these animals will significantly reduce your soil biodiversity, which is a bad thing in its own right (if we accept that these animals are a measure of your soil’s “health” and productivity), and could reduce the numbers of invertebrate-eating wildlife, such as thrushes, hedgehogs and toads, visiting your garden.

If you want your chickens to eat garden pests my advice would be to take the pests to them: scoop up several slugs with a trowel, throw them into their run, and watch the birds excitedly scramble for their treat.  But remember that slugs play a positive role in the garden too, demolishing huge amounts of garden waste in compost bins and (in our garden) eating up cat shit.  That’s a topic for a future post though.

 

*I made a comment to this effect on the Garden Smallholder post but the blog owner saw fit not to allow it to appear.  Draw your own conclusions from that.

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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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.

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

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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.

Pollinator seminar at Westminster – the official version – and that 1,500 figure

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Last month I wrote a personal account of the National Pollinator Strategy Seminar held at Westminster.  This week the Parliamentary Office for Science and Technology released their official summary of the event plus PDFs of the slides of some of the participants.  They can be downloaded from this website.  It was an interesting seminar and it’s well worth taking time to study these documents; they are very accessible for the non-specialist.

One thing that’s unclear to me from this account is with regard to the statement that:  “there are approximately 1,500 insect species that pollinate food crops and wild plants, including bees, hoverflies, wasps, flies, butterflies, beetles and moths”.  The National Pollinator Strategy also cites that figure, though says “at least 1,500” species.

Where does the 1,500 figure come from?  Does anyone know the original citation?  I genuinely can’t recall if I’ve ever seen it published.

A quick back of the envelope, conservative calculation suggests to me that 1,500 species is too low:

Aculeates (bees plus wasps minus ants) =  500
Butterflies =     59
Macro-moths (assumed 50% flower visitors) =  400
Hoverflies =  250
Other flies (assumed 10% flower visitors) =  700
Beetles (assumed 5% flower visitors) =  200
Total species = 2109

 

Links are included to the sources of the original diversity figures.  I’ve rounded some of the figures down and the % flowers visitors figures for moths, flies and beetles is pure guestimate based on my field experience.  But they are not likely to be way out, and if anything could be an under-estimate for flies and beetles; moths could be too high, though most species do feed as adults.  Aculeate Hymenoptera (bees and wasps) could also be an over-estimate, but then that figure doesn’t include the non-aculeate “wasps” that frequently visit flowers, for example many ichneumonids and sawflies.

Does it matter?  I think so: as scientists it’s important that we provide the most accurate data that we can to governments and other bodies that may use it for policy, strategy and advocacy.

As always I’d be pleased to receive your comments.

Urban pollinators for urban agriculture (and horticulture!)

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Over the past few weeks I’ve been thinking a lot about urban pollinators, that is to say bees, hoverflies, butterflies, and other animals, living and foraging in towns and cities.  As I recounted in my recent post about the National Pollinator Strategy seminar at Westminster, Jane Memmott presented some of the first data from the Urban Pollinators Initiative which is looking very interesting.  At the same time, Muzafar Hussain has submitted the first manuscript from his PhD study of urban solitary bees in Northampton, and will hopefully be defending his thesis early next year.  More recently I was asked to examine the PhD thesis of  Rob Fowler at the University of Birmingham, whose focus has been on pollinators across an urban-rural gradient.  Rob did very well and I look forward to seeing his work published.

Interesting though all this work is, it’s largely being done outside the context of crop pollination per se, focusing mainly on the identity and abundance of these urban pollinators.  It’s timely, therefore that a study has just been published by Thebo et al. in the journal Environmental Research Letters entitled  “Global assessment of urban and peri-urban agriculture: irrigated and rainfed croplands” which gives the first comprehensive figures on the extent of agriculture in and around the world’s large towns and cities.  The paper is open-access so you can read its findings for yourself, but the main message is that urban agriculture is more extensive and important than previously assumed, and there are significant implications for food security and water resources.

The research has (justifiably) received quite a lot of publicity in the media, for example on the BBC News website, and is a great contribution to a still limited field of study.  One aspect jumped out at me though; when discussing the limitations of their methods the authors state that: “the scale and methods used……are not structured to capture very small, spatially dispersed areas of urban croplands”.  In other words, urban gardens and allotments are not included in this assessment.  In the UK at least this is a significant limitation as we know that urban fruit and vegetable growing is widespread, though as far as I’m aware there’s no published figures on the volume and value of this local horticulture of food crops.

Which brings us back to urban pollinators: a significant fraction of these crops (large-scale and local garden) requires pollination by insects.  As I reported back in July, in our own urban garden this includes at least 15 crops (strawberries, apples, greengages, cherries, blackcurrants, squashes, courgettes, blackberries, fennel, runner beans, french beans, passion fruit, tomatoes, raspberries, and radish pods).  An integrated study of urban agriculture/horticulture in the context of pollinator diversity and abundance would be a great piece of research and is long overdue.