Monthly Archives: September 2016

Bumblebees, ferries, and mass migrations: an update

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The post earlier this week on the question of “Why do bumblebees follow ferries?” generated quite a few comments, both on the blog and on Facebook.  As I’d hoped a number of people have chimed in to say that they have observed the same thing, or commented that they often see bumblebees when sailing or kayaking out at sea.

Here are the additional observations in increasing distance order to nearest larger area of land.  Distances are approximate and in some cases it’s unclear where exactly the observations were made:

Isle of Mull to the Isle of Staffa: 6.5km

Skye and the Outer Hebrides going in both directions: 24km

Ferry to Jersey: 28.4km

Estonia to Helsinki: 80km – described in a short paper by Mikkola (1984).

However this is nothing compared to evidence that queen bumblebees may engage in mass migrations (involving thousands of bees) across the North Sea from England to Holland, a distance of 165km!  See Will Hawkes’s short article “Flight of the Bumblebee“.

This idea of mass migration is new to me, though the Mikkola (1984) paper cites some earlier literature on the topic.  And this morning I had a quick phone chat with Dave Goulson who tells me that he occasionally gets people contacting him to tell him about such events.  But it’s unclear why these bees should be flying such large distances, how they coordinate their migrations, or indeed how much energy they need to store to travel that far. In addition there are implications for gene flow between British and Continental subspecies of bees such as the Buff-tailed Bumblebee (Bombus terrestris). Even a relatively well studied group of insects such as the bumblebees can continue to surprise us with new questions!

Thanks to everyone who contributed observations and ideas, it’s much appreciated.

Why do bumblebees follow ferries?

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A few years ago I mentioned in my post “Garlicky archipelago” that I had seen bumblebees (Bombus spp.) following the ferry from Southampton to the Isle of Wight, a distance of about 1.5km across water.  If I remember correctly it was my colleague Scott Armbruster who first mentioned this to me: he lives on the Isle of Wight and commutes regularly to the mainland.

I’ve not thought much about this since then as 1.5km is a fairly modest distance for a bumblebee to fly.  But then a few weeks ago I saw the same thing in Denmark, but this time over a much longer distance.

Karin and I were visiting friends on the small island of Sejerø, which (at its closest point) is about 8km from the mainland of Zealand.  To get there you have to catch a ferry which takes about an hour to cross this stretch of water.  About half-way across,  whilst looking over the stern of the ship, I spotted a bumblebee following the ferry.

So that’s twice, on two different ferries and under very different contexts, that I’ve seen this phenomenon.  A pattern is starting to form….  Has anyone else observed this?  Please do comment.

I can think of a few explanations/hypotheses for what’s going on here (some of which are not mutually exclusive):

  1.  Clearly bumblebees do fly across significant stretches of open seawater.  Perhaps all I’m seeing is bees that do this, but spotted from the only vantage point where it’s viewable (i.e. the ferry).
  2. These bumblebees are taking advantage of the slipstream created by the ferry to reduce the energy required to fly these long distances.
  3. The bees are hitching a lift on the ferry and I only observe them as they arrive or depart.
  4. The bees are following the wake of the ship to navigate between the island and the mainland, in order to exploit significant flower patches.  Work by one of my PhD students, Louise Cranmer, a few years ago showed that bumblebees follow linear features such as non-flowering hedgerows to navigate – see Cranmer et al. (2012) Oikos.  Perhaps something similar is happening here?

There’s probably other possibilities I’ve not thought of.  But whatever the explanation, it looks to me as if there’s some potential for interesting experiments marking and recapturing bees on islands/mainland, releasing bees on ferries to see if they follow the wake, etc.  If only Northampton wasn’t so far from the coast….



Spiral Sunday #1 – the start of an obsession

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Spirals have been a bit of an obsession with me for many years, as evidenced by the main image that has always adorned this blog (which, one day, I will tell the story of).  Not sure where that obsession originated but it’s manifested itself in a collection of ceramic bowls with spiral motifs, and with a growing set of photographs that I’ve taken.

This spiral obsession has some relevance to biodiversity.  Spirals are a recurrent feature of nature, and crop up everywhere from the flower heads of members of the daisy family to the whorled shells of gastropod molluscs.  Some of these are governed by mathematical processes such as the Fibonacci Series.  The spiral is also a much better description of the natural sequence of life and death than “the circle of life“.  Circles go back to where they started, which life never does; a spiral, it seems to me, captures that circular forward motion much more effectively, at least when viewed in three dimensions.

Some of the photographs I’ve taken are also of human constructs and cultural artefacts, because the spiral has been a motif used by artists and crafts people for thousands of years, as well as a useful bit of geometry for engineering and architectural purposes.

But, mainly, I just like spirals.  And I need an outlet for this obsession beyond scouring eBay and antique shops for interesting bowls.  Hence I thought I’d start Spiral Sunday*, a regular (maybe) posting of spiral images that I’ve captured, together with a brief description.  It’s possible that this may amuse no one except me, but ho hum.

Spiral Sunday #1 was taken this morning as I harvested the last of our tomatoes.  An undisciplined water regime on our part has meant that some of the fruits have split; in this case tensions within the tomato skin have resulted in a spiral split.


*I freely admit to having been inspired by the “Silent Sunday” feature on the Murtagh’s Meadow blog.  Check it out if you don’t know it.


Urban areas as a refuge for insect pollinators: conservation for the city

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Urban conservation ecology is a fast growing field that has mainly focused on how towns and cities can support populations of plants, animals and fungi that may be declining or threatened in the surrounding rural environment.  That is, the city for wildlife conservation.  In a new essay in the journal Conservation Biology, written with colleagues from across the world, we argue that conservation for the city (an idea originally conceived, I believe, by Steward Pickett) should also be a focus of future research and management activities.

Conservation, or ecology, for the city in essence means that plants, animals and fungi, as well as being supported by the city (see our recent urban bees example), play a role in supporting the city itself through the provision of ecosystem services such as decomposition, flood alleviation, and crop pollination.

It’s pollinators and pollination that we particualrly focus on in this essay – here’s the abstract:

Urban ecology research is changing how we view the biological value and ecological importance of cities. Lagging behind this revised image of the city are natural resource management agencies’ urban conservation programs that historically have invested in education and outreach rather than programs designed to achieve high-priority species conservation results. This essay synthesizes research on urban bee species diversity and abundance to suggest how urban conservation can be repositioned to better align with a newly unfolding image of urban landscapes. We argue that pollinators put high-priority and high-impact urban conservation within reach. In a rapidly urbanizing world, transforming how environmental managers view the city can improve citizen engagement while exploring more sustainable practices of urbanization.

I’m happy to send the PDF to anyone who wants a copy; here’s the full citation:


The macroecology of animal versus wind pollination – a new study just published

In collaboration with colleagues in Brazil, Denmark, and elsewhere in the UK, we’ve just published a new research paper which looks at the global spatial distribution of wind and animal pollinated plant species, and the underlying historical and contemporary ecological causes of that distribution.  It’s a study that builds on my “How many flowering plants are animal pollinated?” paper in Oikos, and has been a long time in its gestation.  We’re very excited by its findings and plan to develop this project in the future.

As a bonus we made the cover of the journal with the amazing image below!  Big thanks to Pedro Viana and Jesper Sonne for the photos.

Here’s the citation with a link to the publisher’s website; the abstract is below.  If anyone wants a PDF copy, please ask.

Rech AR, Dalsgaard B, Sandel B, Sonne J, Svenning J-C, Holmes N & Ollerton J (2016) The macroecology of animal versus wind pollination: ecological factors are more important than historical climate stability. Plant Ecology & Diversity 9: 253-262



Background: The relative frequency of wind- and animal-pollinated plants are non-randomly distributed across the globe and numerous hypotheses have been raised for the greater occurrence of wind pollination in some habitats and towards higher latitudes. To date, however, there has been no comprehensive global investigation of these hypotheses.

Aims: Investigating a range of hypotheses for the role of biotic and abiotic factors as determinants of the global variation in animal vs. wind pollination.

Methods: We analysed 67 plant communities ranging from 70º north to 34º south. For these we determined habitat type, species richness, insularity, topographic heterogeneity, current climate and late-Quaternary climate change. The predictive effects of these factors on the proportion of wind- and animal-pollinated plants were tested using correlations, ordinary least squares (OLS) and logistic regression analyses with information-theoretic model selection.

Results: The proportion of animal-pollinated plant species was positively associated with plant species richness and current temperature. Furthermore, in forest, animal pollination was positively related to precipitation. Historical climate was only weakly and idiosyncratically correlated with animal pollination.

Conclusion: Results were consistent with the hypothesised reduced chance for wind-transported pollen reaching conspecific flowers in species-rich communities, fewer constraints on nectar production in warm and wet habitats, and reduced relative effectiveness of wind dispersal in humid areas. There was little evidence of a legacy of historical climate change affecting these patterns.



Do reference management systems encourage sloppy referencing practices?

Over at the Dynamic Ecology blog there’s an interesting discussion going on about “how to keep up with the literature” that’s relevant to all fields, not just ecology.  Spoiler alert: it’s impossible to “keep up” if “keep up” means “read everything”.  But do check it out as there’s lots of good advice in that post.

One of the topics that’s arisen in the comments is about the use of reference management systems such as Endnote, Refworks, Zotero, Mendeley, etc. Everyone has their own preferences as to which to use, and there seems to be advantages and disadvantages to all of them.  However a minority (so it seems) of us don’t use any kind of reference management system, which strikes those who do as very odd.  Personally, I tried Endnote a long time ago, it was ok, then I lost the database when an old computer bit the dust.

I’m not sure how much more efficient/effective I would be as a publishing academic if I was to get back into using a reference management system. One of the supposed advantages of these systems, that they will format references to the specific requirement of a particular journal, seems to me to be a double-edged sword.  I actually find re-formatting references quite relaxing and I think (though I may be wrong) that it develops attention-to-detail and accuracy skills that are useful in other contexts.

Also I suspect, but have no proof, that reference management software is responsible for perpetuating errors in the reference lists of papers that then result in mis-citations on Web of Knowledge, etc.  My suspicion is that this has got worse over time as people rely more and more on reference management software rather than their brains.  These citation errors can have an impact on an individual’s h-index, as I mentioned in a post last year.

By coincidence yesterday I spotted a hilarious example of just this kind of mis-citation that I think can be blamed on a reference management system. This paper of mine:

Ollerton, J., Cranmer, L. (2002) xxxxxxx Oikos xxxxxx

was rendered in the reference list of another paper as:

Ollerton, J., Cranmer, L., Northampton, U.C., Campus, P. (2002) xxxxxxx Oikos xxxxxx

The last two “authors” are actually from the institutional address – University College Northampton, Park Campus! [UCN is the old name for University of Northampton].

Now in theory that shouldn’t happen if an author’s reference management software is doing its job properly, and information has been correctly inputted, but it does happen: errors are not uncommon.  In addition (it seems to me) authors often don’t check their reference lists after they have been produced by the reference management software. That’s sloppy scholarship, but I can understand why it happens: people are busy and why bother if the software is (in theory) getting it right every time?  It also shouldn’t happen at the editorial production end of things, because references are usually cross-checked for accuracy, but again it does, even for top-end journals (in this case from the Royal Society’s stable!)

Again it’s anecdotal but I’m also noticing that reference lists in PhD theses that I examine are getting sloppier, with species names not in italics, various combinations of Capitalised Names of Articles, unabbreviated and abbrev. journal names, etc. etc.

Does any of this really matter?  Isn’t it just pedantry on my part?  Whilst the last statement is undoubtedly true, I think it does matter, because attention to detail at this very basic level gives the reader more confidence that attention has been paid at higher levels, such as citing accurate statistics from primary sources to back up statements, rather than relying on secondary sources, as Andrew Gelman discussed in an old blog post on referencing errors.

But maybe I’m a lone voice here, I’d be interested in your thoughts.

Two-day Steven Falk bee ID course at Oxford University Museum 15th-16th October 2016

Male B lap on Salvia cropped P1120309

One of the most exciting, pollinator-related publishing events of last year was the publication of Steven Falk’s eagerly-anticipated Field Guide to the Bees of Britain and Ireland.  Not only does this book provide a state-of-the art account of the natural history and identification keys for all of the bees currently known from Britain (over 270 species) but it’s backed up by Steven’s own Flikr site with more photographs of the bees, including lots of close ups, and an ongoing list of updates and corrections.

But as Steven himself acknowledges, the identification of many of our bees is a challenge, even with the book and the additional imagery.  Anyone who is really keen to get to grips with bee identification is therefore recommended to book onto a hands-on identification course.  Steven has just announced that he is running a two-day course in Oxford on 15th to 16th October, at a cost of £60 per person – here’s a link to the booking page.  Seems like good value to me!

Elsevier successfully patents a common peer review process

As reported yesterday on Mike Taylor’s Sauropod Vertebra blog, who in turn picked up the story from the site, at the end of August the giant publisher Elsevier successfully patented what they see as a unique form of peer review: waterfall (or cascading as it’s long been known) peer review. This is described as “the transfer of submitted articles from one journal to another journal” owned by the same publisher.  And there’s nothing new about it, it’s been accepted practice for a number of publishers for years now.

If you want to look at the original U.S. patent, here’s a link to it.

I don’t often re-work the content of others’ blogs, but his is exceptional: the motivation for Elsevier’s actions seem dubious at best and it’s worth clicking through and reading those pieces in detail.  What is Elsevier thinking?

The timing of this one story is also interesting.  It’s as if the Gods of Publishing had actually read my last post about peer-reviewed versus non-peer-reviewed publishing, and decided to have some fun with us mere mortals…..