Tag Archives: Nature

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.

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Filed under Biodiversity, History of science, Pollination

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

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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: https://twitter.com/JMBecologist/status/1165565465705496576

 

 

 

 

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

“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:  https://twitter.com/JeffOllerton/status/1159377089319047168

 

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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:

 

Belgian:

https://www.wildbnb.brussels/

 

Brazilian:

https://www.semabelhasemalimento.com.br/home/polinizacao/

https://abelha.org.br/

 

Chilean:

https://www.abejasdechile.com/

 

Dutch:

http://sapoll.eu/nl/  

http://www.bestuivers.nl/ 

https://www.nederlandzoemt.nl/

 

French:

https://www.pollinis.org/ 

http://www.florabeilles.org/

 

French Canadian:

http://m.espacepourlavie.ca/des-pollinisateurs

 

German:

http://wildbienen.info

http://wildbienen.de 

http://wildbiene.com

 

Norwegian:

https://snl.no/honningbie

https://www.lahumlasuse.no/humlens-liv/

 

Portuguese:  

http://www.cienciaviva.pt/aprenderforadasaladeaula/index.asp?accao=showobj&id_obj=1532

 

Spanish:

http://www.abejassilvestres.es/index2.html

http://apolo.entomologica.es/

http://www.rjb.csic.es/jardinbotanico/jardin/index.php?Pag=697&len=

 

With thanks to everyone on Twitter who responded.

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Filed under Bees, Biodiversity, Pollination

Tantalising evidence for a new type of pollination system in Madagascan Apocynaceae

cynanchum obovatum with wasp_madag -angavokely_meve 1

As I recounted in my post last summer, the plant family Apocynaceae contains species with a very wide diversity  of pollination systems – see:  The evolution of pollination systems in one of the largest plant families: a new study just published – download it for free.  Confirmed pollinators include bees, birds, moths, butterflies, flies, beetles, and wasps of a dizzying diversity.  So I was intrigued to receive an email earlier this week from my colleague Prof. Dr Ulrich “Ulli” Meve of the University of Bayreuth with the subject line “Wasp expert needed”.  Ulli is an authority on Apocynaceae taxonomy, also has an interest in their pollination biology, and is a co-author of the study last year.

Attached to the email were a couple of images showing a wasp visiting flowers of Cynanchum obovatum, an endemic species of Apocynaceae from northern and eastern Madagascar.  Ulli had taken the photographs during field work there in preparation for the Flora of Madagascar project.  Here’s the global distribution of the species according to GBIF records:

cynanchum obovatum from gbif

I was excited because Madagascar has a very rich diversity of Apocynaceae (between 500 and 1000 species).  However we have flower visitor observations for only a small fraction of them, fewer than 20 species, and good evidence that the visitors are pollinators for only a couple of those.

I didn’t immediately recognise the family to which the wasp belonged: it didn’t look like either Vespidae or Pompilidae, two groups that are known pollinators of Apocynaceae.  So I uploaded the shots to the Hymenopterists Forum on Facebook and within minutes had received an answer:  it was a species of Scoliidae, commonly referred to as scoliid wasps.  The distinctive wing corrugation found in this family is clearly visible on this image:

cynanchum obovatum with wasp_madag -angavokely_meve 2

Scoliids are parasitoids of beetles and are some of the world’s largest wasps, but it’s not a very diverse family, with only about 560 described species, and only a single species in the UK (on the Channel Islands).  Compare that with the Pompilidae and Vespidae, both of which contain c. 5,000 species worldwide.

Ulli tells me that when he saw the scoliid on C. obovatum “the wasp knew what to do with the flowers”, something I’ve experienced with vespid and pompilid wasp pollinated species in Africa: these wasps are really familiar with the flowers, they know how to work them to get a reward as they are regular and committed visitors.  We believe that this is likely to be the legitimate pollinator of the plant, in which case it’s one of the few records for Scoliidae pollinating Apocynaceae, and the first for Madagascar.  Other examples are mainly in South America, India and South Africa, and usually as one of a broad set of other wasps and/or bees visiting generalist flowers.

It’s interesting that this species of Cynanchum is one of the few in which the corona which covers the gynostegium (the fused sexual parts) is closed over:

cynanchum obovatum_madag - angavokely_meve

That means it requires quite a strong, large insect to get inside and access the nectar.  So the prediction is that the pollen masses (pollinaria) will be found on the mouthparts of these wasps.  Intriguingly, a very closely related species C. repandum has no such closed corona, begging the question of whether it might be pollinated by a different type of insect:

cynanchum repandum sl 2867_low

For now this record will go into the Pollinators of Apocynaceae database as pollinator unproven, but i would be great if someone working in Madagascar could confirm the status of this pollination system.

My grateful thanks to Ulli for sharing his pictures and allowing me to tell the story of what may be a whole new Madagascan pollination system for our favourite family.  Apocynaceae is full of surprises!

cynanchum obovatum with wasp_madag -angavokely_meve 3

 

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Filed under Apocynaceae, Biodiversity, Pollination, Wasps

Photograph and poem: the only alien here

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Wind the propagator propels air-borne seeds

To urban refuge and new opportunity

Where they germinate, elongate, grow, and flower,

Roots seeking soil, making do with mortar and render,

As, persistent in its invader role,

Buddleia grips a gable cliff, dispensing offspring

From house wall warmth into frigid space

And a clear night of stars backdrops the only alien here.

 

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Filed under Biodiversity and culture, Personal biodiversity, Poetry, Urban biodiversity

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 3

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.

UPDATE 3: This issue rolls on and Nature is still allowing commentary.  Just before Christmas Jonathan Davies and Peter Stoett wrote on behalf of the authors of the biodiversity section of the newest Global Environment Outlook (GEO-6) from UNEP  (due March 2019) that “Biodiversity loss is dire, don’t get distracted“.

 

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Filed under Biodiversity, Ecosystem services, IPBES, Pollination

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.

20180926_121532

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

Why I’m joining the People’s Walk for Wildlife on Saturday 22nd September

Peoples walk for wildlife

If you live in the UK and have an interest in wildlife you’ve probably heard about the event that takes place in London this coming Saturday:  The People’s Walk for Wildlife.  If you follow that link you’ll find a video of Chris Packham explaining what the walk is all about and why he’s organised it, plus logistical information, timings, etc.

Karin and I are going to join the walk and I thought I’d give a brief summary of why I think it’s important for people to take part.

If you watch the video you’ll see that Chris does a great job of laying out the issue of wildlife loss, a loss not just of species but of abundance.  There are species that still can be found in Britain but which have declined in numbers by 90% or more over my lifetime.  Such species can be found in all of the major groups of biodiversity in this country:  birds, mammals, fish, reptiles and amphibians, insects and other invertebrates, fungi, and plants.  Many, many millions of individuals gone from our countryside.

Why has this happened?  Well, the causes are complex and inter-related.  Agricultural intensification over the last century has been a major issue as I’ve previously discussed on this blog in relation to pollinator extinctions.  But that’s only part of it. Another big problem that we have in the UK is an unwillingness to let nature just get on with itself.  We feel that we have to manage everything: Too many ravens?  Cull them.  Hedgerows or road verges looking a bit untidy?  Cut them.  Old tree infected with a fungus?  Chop it down.

In part this mindset is linked to an idea of what natural heritage should look like, an idea of order within a landscape, of making the countryside look pretty, and of doing things simply because that’s what our predecessors did.  A good example was recently tweeted by Dave Goulson who had found mole traps on a Natural Trust property that he visited; as Dave rightly said:  “When will we stop slaughtering harmless wildlife that causes us the tiniest inconvenience?”  There is no reason in this day and age to kill moles – what conceivable harm do they do?  In fact, as ecosystem engineers, they are an important part of the ecology of the British countryside.

One of the reasons why this is happening largely unnoticed by the government agencies responsible for the environment is that our landscapes change at a very slow rate.  Indeed places like the Lake District or the Scottish Highlands or the Chiltern Hills look much the same as they have done for hundreds of years.  Visually they are still stunning places to visit and that’s why they attract millions of tourists every year, and also why people enjoy living there.  But they have lost much of their wildlife and, with it, some of the ecological function that makes them work as ecosystems.  If this continues then natural processes such as dispersal of seeds by birds and mammals, and the subsequent maintenance of tree populations, will cease.

But that’s okay isn’t it?  Trees and shrubs not establishing themselves: go out and plant them by hand.  Is this really what we want?  If it is then we will end up turning our countryside into a museum.  And not even a very good museum at that: not a museum with dynamic interactive displays, rather a static, dull set of exhibits that you can only peer at through dusty glass.

So that’s why we are joining the People’s Walk for Wildlife next Saturday: this is an important issue and people need to show government that they are concerned.  I hope you agree and I hope you will join us.

Dave G. has promised to come dressed as a bumblebee; I’ve seen his costume and he’s a man of his word, so it’ll be worth looking out for him.  I can’t promise anything so flamboyant but I may well take a placard that says something like:  “Save ALL of our pollinators, not just bees!”  If you spot it, do some over and say hello.

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Filed under Bees, Biodiversity, Ecosystem services