Tag Archives: Science

The evolution of pollination systems in one of the largest plant families: a new study just published – download it for free

Figure 1 JUNE revision

Interactions between flowering plants and the animals that pollinate them are known to be responsible for part of the tremendous diversity of the angiosperms, currently thought to number at least 350,000 species.  But the diversity of different types of pollination system (bird, bee, moth, fly, etc.) is unknown for most large, related groups of plants (what systematists term “clades”) such as families and subfamilies.  In addition we know little about how these interactions with pollinators have evolved over time and in different parts of the world.  Only a handful of groups of flower plants have been studied with respect to questions such as:

How much do we currently know about the diversity of pollination systems in a large clades?

How is that diversity partitioned between the smaller clades (e.g. subfamilies, tribes, genera) of a family, and what are the evolutionary transitions between the major groups of pollinators?

Do these pollination systems vary biogeographically across the clade’s range?

These sorts of questions have been addressed for the massive, globally distributed Apocynaceae (one of the top 10 or 11 largest angiosperm families with more than 5,300 species) in a study just published using a new database of pollinators of the family.  What’s more, the work is open access and anyone can download a copy for free.  Here’s the citation with a link to the paper:

Ollerton, J., Liede-Schumann, S., Endress, M E., Meve, U. et al. [75 authors in all] (2018) The diversity and evolution of pollination systems in large plant clades: Apocynaceae as a case study. Annals of Botany (in press)

In this study we have shown that (among other things):

  • The family is characterised by an enormous diversity of pollination systems involving almost all of the major pollen vectors and some that are nearly unique to the Apocynaceae.
  • Earlier diverging clades have a narrower range of pollination systems than those that evolved later.
  • Transitions from one type of pollination system to another are evolutionarily constrained, and rarely or never occur, whereas others have taken place much more often, e.g. between wasp and beetle pollination.
  • There is significant convergent evolution of pollination systems, especially fly and moth pollination, by geographically and phylogenetically distinct clades.

You’ll notice that there are 75 (!) authors on this paper.  That’s because we’ve pulled together a huge amount of previously unpublished data and used some state of the art analyses to produce this work.  It was a monumental effort, especially considering that my colleague Sigrid Liede-Schumann and I only decided to push ahead with this project about a year ago when we chatted at the International Botanical Congress that I posted about at the timeIn truth however the origins of this paper go back over 20 years to 1997 when when Sigrid and I published a study of what was then known about pollination systems in the Asclepiadaceae (the asclepiads).

In that paper we said that the research “is intended to be ongoing…[we]…hope to re-review asclepiad pollination within the next decade”.  At the time I didn’t think it would actually take more than 20 years!  However over that period a lot has changed.  For one thing the Asclepiadaceae no longer exists, broken up and subsumed within a much larger Apocynaceae.  Also, I’ve done a lot of work in the field and in the herbarium on some of the smaller groups within the family, such as CeropegiaOthers, including many of my co-authors, have also been working on different groups in various parts of the world.  Finally the level of sophistication of the analyses we are now able to do has increased beyond recognition compared to what we could achieve in the mid-1990s.  All of this means that now is the right time to produce this study.

Having said all of that, this is still a work in progress.  Our Pollinators of Apocynaceae Database contains a sample of just over 10% of the species in the family.  So lots more data on plant-pollinator interactions needs to be collected before we say we fully understand how pollination systems have evolved in this most remarkable family.  I’d be happy to talk with anyone who is interested in the family and being involved in future data collection.

The database will be freely available to anyone who wants to use it – lots more can be done with this information and, once again, I’m happy to chat with potential collaborators.

I was recently interviewed about the study, and about plant-pollinator interactions and the Apocynaceae more generally, for the In Defense of Plants podcast – here’s a link to that interview.

Finally, I’d like to express my sincerest thanks to my co-authors on this study – I really couldn’t have done it without you guys!

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Filed under Apocynaceae, Biodiversity, Biogeography, Evolution, Pollination, Wasps

British phenological records indicate high diversity and extinction rates among late-summer-flying pollinators – a recently published study

Balfour et al Figure 1

Natural history records of plant flowering and pollinator foraging, much of them collected by well informed amateurs, have huge scientific importance. One of the values of such records to ecology is that it allows us to document where these species occur in space and when they are active in time. This can be done at a range of spatial and temporal scales, but large-scale patterns (for example at a country level) are, I think, especially useful because they provide scientific evidence that can inform national conservation strategies.

During 2017 I collaborated with a young early career researcher at the University of Sussex, Dr Nick Balfour, on an analysis of the phenologies of British pollinators and insect pollinated plants.  That study was recently published (see citation below) and I think that the results are fascinating.

Nick did most of the leg work on this, which involved assessing more than one million records that document the activity times of aculeate wasps, bees, butterflies and hoverflies held in the databases by three of the UK’s main insect recording organisations, the Bees, Wasps and Ants Recording Society (BWARS), the UK Butterfly Monitoring Scheme (UKBMS) and the Hoverfly Recording Scheme (HRS).  Information on flowering times was taken from a standard British flora (Clapham et al. 1990 – Flora of the British Isles. Cambridge University Press).

As well as looking at annual flight periods and flowering trends for these organisms we also focused on pollinator and plant species that were endangered or extinct. Here are some headline results and thoughts on what the work shows:

  • About two-thirds (62%) of pollinator species peak in their flight times in the late summer (July and August), though there was some variation between the different groups – see the figure from the paper above).  Particularly noticeable was the double peak of the bees, with the first peak denoting the activity of many early-emerging solitary bees, such as species of the genus Andrena, whilst the second peak is other solitary bees plus of course the bumblebees which by that time have built up their colonies.
  • A rather fixed phenological pattern with respect to different types of plants was also apparent, which I was not expecting at all: insect pollinated trees tend to flower first, followed by shrubs, then herbaceous species (again, refer to the figure above). This might be because larger plants such as trees and shrubs can store more resources from the previous year that will give them a head start in flowering the following year, but that idea needs testing.
  • Putting those first two points together, what it means is that trees tend to be pollinated by those earlier emerging bees and hoverflies, whereas the herbs are mainly pollinated by species that are active later.
  • When looking at the extinct and endangered pollinators, the large majority of them (83%) were species with a peak flight times in the late summer, a much larger proportion than would be expected given that 62% of all species are active at that time. However this was mainly influenced by extinct bee species and the same pattern was not observed in other groups.
  • The obvious explanation for that last point is that historical changes in land use have led to a dramatic reduction in late summer flowering herbaceous species and the subsequent loss of floral resources has been highly detrimental to those bees. But intriguingly no such pattern was apparent for the endangered pollinators and clearly there are complex reasons why pollinators should become rare or extinct, a point that I have discussed previously on the blog.
  • The lack of late summer flowering resources for pollinators is a contentious issue however as plant conservation groups have in the past recommend that meadows and road verges are cut in late summer to maximise plant species richness.  Mowing road verges once or twice a year certainly benefits plant diversity, as this recent review by Jakobsson et al. (2018) demonstrates.  But there’s very little data available that assesses how timing of cutting can affect pollinators.  The only study that I know of (and if I’ve missed any, please let me know) that has considered this is the PhD work of one of my former students, Dr Sam Tarrant who looked at pollinators and plants on restored landfill sites compared to nearby nature reserves.  In a paper that we published in the journal Restoration Ecology in 2012 we showed that on restored landfill sites the abundance of pollinators in autumn surveys (conducted September-October) was just as high as for summer surveys.  On nature reserves, which are routinely cut from mid-July onward, this was not the case.

Here’s the full citation of Nick’s study with a link to the publisher’s website, and a copy of the abstract is below.  If anyone wants a PDF, drop me a line:

Balfour, N., Ollerton, J., Castellanos, M.C., Ratnieks, F.L.W. (2018) British phenological records indicate high diversity and extinction rates among late-summer-flying pollinators. Biological Conservation 222: 278-283

Abstract:

The long-term decline of wild and managed insect pollinators is a threat to both agricultural output and biodiversity, and has been linked to decreasing floral resources. Further insight into the temporal relationships of pollinators and their flowering partners is required to inform conservation efforts. Here we examined the
phenology of British: (i) pollinator activity; (ii) insect-pollinated plant flowering; and (iii) extinct and endangered pollinator and plant species. Over 1 million records were collated from the historical databases of three British insect monitoring organisations, a global biodiversity database and an authoritative text covering the national flora. Almost two-thirds (62%) of pollinator species have peak flight observations during late-summer
(July and August). This was the case across three of the groups studied: aculeate wasps (71% of species), bees (60%), and butterflies (72%), the exception being hoverflies (49%). When species geographical range (a proxy for abundance) was accounted for, a clear late-summer peak was clear across all groups. By contrast, there is marked temporal partitioning in the flowering of the major plant groups: insect-pollinated tree species blossoming predominantly during May (74%), shrubs in June (69%), and herbs in July (83%). There was a positive correlation between the number of pollinator species on the wing and the richness of both flowering insect pollinated herbs and trees/shrubs species, per calendar month. In addition, significantly greater extinctions occurred in late-summer-flying pollinator species than expected (83% of extinct species vs. 62% of all species). This trend was driven primarily by bee extinctions (80% vs. 60%) and was not apparent in other groups. We contend that this is principally due to declines in late-summer resource supplies, which are almost entirely provisioned by herbs, a consequence of historical land-use change. We hypothesize that the seasonality of interspecific competition and the blooming of trees and mass-flowering crops may have partially buffered spring flying pollinators from the impacts of historical change.

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Filed under Bees, Biodiversity, Butterflies, Hoverflies, Macroecology, Pollination, Wasps

A once in a lifetime sunset?

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It’s been a curious year in the UK, weather wise, with an early, mild spring interspersed by sudden cold snaps that may (or may not) have had a profound impact on pollinators, and then a summer that was hotter and drier than any in living memory.  There’s been some amazing thunderstorms and torrential rains, and weeks when there was no rain at all.  Then, on Thursday evening, as Karin and I were coming back from a walk around Abington Park (via a quick stop in the pub) the heavy, rain-bloated skies conspired with the setting sun to produce, for a brief period, a display of light and clouds that was more vibrant and gorgeous than any I’ve ever seen.  The sky reflecting from the rain-soaked pavements of Northampton added further drama to what may well be a once in a lifetime experience.

Here are a few shots I managed to take using the camera on my phone; I’ve not altered the colour or played with images in any way, but they do partial justice to the quality of the light that evening.

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Filed under Biodiversity, Climate change

The impact of building a new university campus on urban bird diversity and abundance: a seven-year study

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Over the past few years I’ve posted several pieces about how colleagues, students and myself have been monitoring one aspect of the environmental impact of the University of Northampton’s brand new 22 ha, £330 million Waterside Campus development.  Specifically we have been looking at how the construction work has affected bird diversity and abundance in and around the site: see my posts “An interim report on the Waterside bird surveysand “Monitoring the impact of the new Waterside Campus“.

Our approach has been to repeat the baseline bird surveys (three winter and three spring) that were done in 2012/13 as part of the environmental impact assessment prior to work taking place.  The new campus opens this summer and, following our most recent set of surveys in April/May, it’s time to reveal our findings so far.  Here are the headlines:

The baseline surveys recorded a total of 52 bird species.  In the following graphs birds have been categorised according to their RSPB Red, Amber, Green status.  Four species from the original surveys remain unrecorded:  Marsh tit, Bullfinch, Collared dove, and Lesser whitethroat.  However at least two of these (Bullfinch and Collared dove) are still found within 1km of the site.

During the repeat surveys we have recorded an additional 25 species that were not found in the baseline surveys.  This is not surprising – bird assemblages are dynamic, given that most species are very mobile – but it’s still interesting to find that so many more species are finding homes in the area.  If the four “missing” species return then the potential full diversity of the site is at least 77 species:

Waterwide birds - RAG

However this overall good news story is more complex than it first appears.  In the graph below I have plotted the Simpson’s Index for each survey, with a LOESS regression showing 95% confidence limits.  Simpson’s Index combines the data on both the number of species and their abundance to provide an overall measure of the impact of the construction work.  It’s clear that during the main phase of construction the average bird diversity per survey dropped significantly.  Following the completion of the noisiest and most disruptive activities, diversity has started to return to its pre-construction levels:

Waterside Simpsons

This overall assessment hides a lot of detail; as you can see below, Green status birds have fared best, Amber status birds have done ok; Red status birds have fared worst, especially in spring, but better in winter:

Waterside red amber green

The bird diversity is not quite back to what it was, but overall our findings are very encouraging.  In the initial phases of the development we talked with the landscape architects about adding ecological value to Waterside by including more native trees, reed beds, wild flower meadows, etc.  We’ve yet to assess how these features will affect biodiversity on the site, including birds, but we might predict that the final diversity exceeds that of the original brownfield site.  With that in mind we will be doing at least one more cycle of three winter and three spring surveys during 2018/2019.

Long-term monitoring of this kind is almost never undertaken for infrastructure projects of this nature. Universities, I would argue, need to take a lead in promoting such activities and making then a common component of the planning process.  From this work I think that our main conclusion is that redevelopment of peri-urban brownfield sites such as this doesn’t have to mean a loss in biodiversity, at least not as far as the birds are concerned.  We also plan future surveys of mammals, plants and invertebrates to assess how they are doing.

My thanks to all the colleagues and students who have been involved in the work so far: Duncan McCollin, Janet Jackson, Joanne Underwood, Kirsty Richards, Suzy Dry, Charles Baker, Pablo Gorostiague, Andrew Hewitt.

To finish, here are some photographs that we took of the work being carried out so you can see the scale of what has been achieved at Waterside:

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Filed under Biodiversity, Birds, University of Northampton, Urban biodiversity

An inordinate fondness for “an inordinate fondness for”: origin of an over-used title element

Soldier beetles

There is an oft-told story about the biologist JBS Haldane.  Sitting with a group of theologians over dinner he was asked what his studies of the natural world had led him to conclude about God.  After a pause, Haldane replied “He has an inordinate fondness for beetles”.  The story is almost certainly apocryphal, though Haldane was fond of saying similar things – see this dissection of the evidence for example

True or not, it’s a nice story that does in fact say something profound about the Earth’s biodiversity: beetles (Coleoptera) are far more species-rich than almost any other Order of insects.  I say “almost” because the Dipterologists are convinced that the true flies (Diptera) have more species.  And they may well be correct given that flies are less well studied than beetles, and a 4 ha area of tropical forest in Costa Rica can support an astounding 4,332 species, with the prediction that many more would be found with further sampling.

Regardless of the accuracy of the quote and of the statistics underlying it, the phrase “an inordinate fondness for” has inspired quite a number of titles of academic papers, chapters, and books – here’s some examples:

Fisher (1988) An inordinate fondness for beetles. Biological Journal of the Linnean Society

May (1989) Ecology – an inordinate fondness for ants. Nature

Evans & Bellamy  (1996) An inordinate fondness for beetles. Henry Holt & Co.

Rouse et al. (2018) An inordinate fondness for Osedax (Siboglinidae: Annelida): Fourteen new species of bone worms from California. Zootaxa

Sochaczewski (2016) An inordinate fondness for beetles. The hero’s journey of Alfred Russel Wallace. In: Naturalists, Explorers and Field Scientists In South-East Asia And Australasia. Book Series: Topics in Biodiversity and Conservation

Thomas et al. (2015) Charles A. Triplehorn: an inordinate fondness for darkling beetles. Coleopterists Bulletin

Vieira et al. (2014) Toward an inordinate fondness for stars, beetles and Lobophora? Species diversity of the genus Lobophora (Dictyotales, Phaeophyceae). New Caledonia Journal of Phycology

Clare et al. (2014) An inordinate fondness for beetles? Variation in seasonal dietary preferences of night-roosting big brown bats (Eptesicus fuscus). Molecular Ecology

Dyer et al. (2014) New dimensions of tropical diversity: an inordinate fondness for insect molecules, taxa, and trophic interactions. Current Opinion in Insect Science

Kasson et al. (2013) An inordinate fondness for Fusarium: phylogenetic diversity of fusaria cultivated by ambrosia beetles in the genus Euwallacea on avocado and other plant hosts. Fungal Genetics and Biology

Mann et al. (2013) An inordinate fondness? The number, distributions, and origins of diatom species. Journal of Eukaryotic Microbiology

Chase (2013) An inordinate fondness of rarity. PLoS Biology

Harmon (2012) An inordinate fondness for eukaryotic diversity. PLoS Biology

Hamuli & Noyes (2012) An inordinate fondness of beetles, but seemingly even more fond of microhymenoptera!  Newsletter of the International Society of Hymenopterists

Eide (2012) An “inordinate fondness for transporters” explained? Science Signaling

Snider et al. (2012) An inordinate fondness for rocks: roosting habits of bats at Mesa Verde National Park, Colorado. Bat Research News

Longino & Snelling (2009) An inordinate fondness for things that sting. Journal of Hymenoptera Research

Maderspacher (2008) Genomics: an inordinate fondness for beetles. Current Biology

Sandvik (2006) An inordinate fondness for Mecopteriformia. Systematics and Biodiversity

Grove & Stork (2000) An inordinate fondness for beetles. Conference: Celebration Symposium on A World of Beetles: Canberra, Australia.

Ashworth, Buckland & Sadler (1997) Studies in Quaternary entomology: an inordinate fondness for insects. John Wiley.

Bamber & Błażewicz-Paszkowycz (2013) Another inordinate fondness: diversity of the tanaidacean fauna of Australia, with description of three new taxa. Journal of Natural History

I’m sure there’s other that I missed, but you get the idea.  The phrase “an inordinate fondness for” seems to be a bit over-used now and I wonder whether some of these papers might have benefitted from a more descriptive title?  The title one chooses for a paper or a book really matters – see this old Small Pond Science blog post on the topic.  I’m sure that there’s research published showing that papers with titles which describe their findings are more frequently cited but I can’t immediately find it.  Perhaps one of my readers knows?

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Hunting the Chequered Skipper: an encounter with England’s latest species reintroduction project

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If you have been following recent conservation news on social media you’ll know that this week was an important one for invertebrates.  The Chequered Skipper, a butterfly last seen in England in 1976, has been reintroduced to the country as part of the Back From the Brink initiative.  The Chequered Skipper project is led by Butterfly Conservation and a team travelled to a site in Belgium earlier in the week where about 40 skippers were captured.  These insects were transported back to the UK where they were held overnight in mesh cages at a secret location in order to acclimatise them, then released into the wild.  The release was filmed as part of next week’s BBC Springwatch series – look out for it.

The exact location of the reintroduction is secret.  However I can tell you that it’s occurred in the Rockingham Forest area of north Northamptonshire, in habitat that (over the past couple of years) has been managed specifically for this reintroduction, in order to create a network of sites across which the species could disperse in the future.  This area was the last stronghold of the species in England prior to its extirpation.  No one knows why it went extinct here, but hung on and did well in Scotland, but it may relate to climate: 1976, as many of the middle-aged will remember, was a very hot, dry summer, and this butterfly likes it warm and humid.

Yesterday I had the privilege of seeing this reintroduction first hand when I visited the site with my colleague Dr Duncan McCollin.  Duncan and I are supervising a PhD student, Jamie Wildman, along with Prof. Tom Brereton, Head of Monitoring at Butterfly Conservation (BC), and the University of Northampton’s Visiting Professor in Conservation Science.  Jamie’s project will focus on understanding the habitat requirements for Chequered Skipper, and monitoring the success of the reintroduction.  I’m also hoping that it might be possible for Jamie to assess the role of this species as a pollinator of the plants it visits.  Butterflies as pollinators is a very under-researched area.

Here’s a shot of the Four Mus-skipper-teers* just before we set off to help BC volunteers to locate the skippers and record their behaviour:

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The day started unpromisingly.  It was cool and overcast, and little was flying except some hardy Common Carder Bees.  But around lunchtime things began to warm up and gradually the sun broke through and we started to see flying Lepidoptera that we excitedly chased, only to be disappointed by yet another Mother Shipton or Silver Y.  But no skippers.

As we encountered some of the BC volunteers who were also tracking the insects we were told that we had “just missed one” or that they “saw one down that ride, we marked the spot”.  One volunteer wanted to show me a photo of a Chequered Skipper that he’d just taken “so I could get my eye in”.  I politely refused; I wanted to see the real thing and didn’t want to jinx it with a digital preview.

Finally, our efforts were rewarded and we found the first skipper of several we later encountered.  The image at the head of this post is that butterfly, a sight that has not been seen in England in more than 40 years.  An exciting and privileged encounter.  The county Butterfly Recorder, David James (on the right in this next shot), is ecstatic that the reintroduction has occurred “on his patch” but also nervous at the responsibility it represents:

Skipper crew 2018-05-26 13.15.06

Later we spent time helping Jamie follow a female skipper who was showing egg-laying behaviour, moving slowly for short distances along a shrubby edge, occasionally nectaring on Bugle, and diving deep into the vegetation to (we hope) oviposit on grass leaves:

 

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Although I’ve over-cropped this next image of the skipper on Bugle, I thought I’d leave it as I like the different textures and patterns, and the slightly blurry ambience:

Skipper nectaring 2018-05-26 13.06.08

The primary aim of Butterfly Conservation’s project is to return a small part of England’s lost biological heritage.  But it’s about more than just the Chequered Skipper.  It’s also about understanding how managing a network of sites for this flagship species can benefit other organisms.  The wide woodland rides that have been created are packed with plant species, amongst them at least five grasses that could be used as caterpillar food sources for the skippers, plus more than 20 nectar sources were flowering that they (and other flower visiting insects) could use.  Those other insects were plentiful too: over the day I spotted five species of bumblebees, several different day flying moths, lots of Dark-edged Bee Flies, and a few different solitary bees and syrphids flies.  We heard calling cuckoos, and four different warblers: chiffchaffs, garden warbler, whitethroats, and blackcaps.  Red kites (another incredibly successful species reintroduction) floated overhead skimming the treetops as they their cried to one another.

Rockingham Forest is a lovely part of Northamptonshire, well worth a visit.  The Chequered Skipper will be a wonderful addition to its biodiversity.  Of course there are no guarantees that the reintroduction part of the project will be a success, but if it isn’t it won’t be because of a lack of commitment from the people involved.  If the population does become established then in the future the location will be made public and butterfly enthusiasts will be able to come and pay homage to one of the few butterflies with a pub named after it.

 

*You get the puns you deserve on this blog…..

 

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Filed under Bees, Biodiversity, Birds, Butterflies, Pollination, University of Northampton

Why conservation is like paella: thoughts and photos from our Tenerife field trip

 

A couple of days ago I posted a photograph on Facebook with a comment that “after a hot day of collecting data there’s nothing better than a nice big Tenerife paella!”:

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My wife Karin and I had ended up in the small town of Candelaria, tired and hungry after sweating our way through the Malpais de Guimar  counting and measuring plants.  Big plates of hot food were just what we needed!

After I posted the image a Spanish colleague commented that the dish was “closer to being an arroz con cosas than a paella”.  The term translates as “rice with things” and is used to convey the fact that the original Valencian dish of paella has been bastardised and changed across the Spanish-speaking world, and no longer reflects its culinary tradition.  Knowing nothing of that culinary tradition I took a look at the Wikipedia entry for paella.  It makes for interesting reading, not least the fact that in the original dish one of the main ingredients was the meat of water voles and that the dish was cooked on an open fire fuelled by wood from orange and pine trees to give a distinctive smoky flavour.  There was also a lot of geographic variation in the dish, so what constitutes an authentic paella is debatable.

Although there was no sign of rodent flesh or naked flames in the dish that we ate, it was certainly delicious!  But the comment about arroz con cosas got me thinking about shifting baselines in cooking and conservation.

The idea of a shifting baseline is that expectations of what is “correct” or “normal” or “natural” change over time depending upon what each generation has experienced.  It’s been mainly applied in conservation; for example, the Lake District of England is seen by many as a “natural” landscape of rolling hills and low mountains, but originally it would have been covered in deciduous forest.  Likewise large parts of Tenerife contain a high proportion of alien plants (such as agave and prickly pear) but local people and visitors see this as natural.  The baseline of “naturalness” has shifted for people.  Returning these landscapes to their original condition would mean a drastic shift in the composition of the vegetation.  And what point do we return that condition to?  One hundred years ago?  One thousand?  Ten thousand?  It’s an issue that is widely debated in the conservation literature, especially in relation to rewilding.

Likewise, over time paella has evolved and been adapted by different chefs, and what is currently cooked in restaurants only partially reflects how the dish was originally cooked.  Other than for epicurean purists, our culinary expectations have changed.  There’s been a shift in the paella baseline.

Anyway, enough metaphorising, here are some photographs from out trip.  To set the context, University of Northampton students and staff, including Pablo Gorostiague who is visiting from Argentina, and colleagues from the University of Sussex (Maria Clara Castellanos and Chris Mackin), were out with us last week.  Then we bade them farewell on Sunday before moving on to do some field work.

Field work on the lava fields at Santiago del Teide:

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The landscape of Malpais de Guimar, which actually probably hasn’t changed much in the last 10,000 years:

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Howe many people can you fit around Pino Gordo, the largest Pinus canariensis on the island:

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The endemic Tenerife Blue Chaffinch:

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The cold, damp laurel forest:

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Team Nicotiana!  Helping Chris with locating Tree Tobacco populations for his PhD work:

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Pablito takes a break:

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Filed under Biodiversity, Biodiversity and culture, Rewilding, Tenerife, University of Northampton

Trait evolution, resource specialization and vulnerability to plant extinctions among Antillean hummingbirds – a new study just published

Hummingbird bowl from BM

Hummingbirds are fascinating creatures and important pollinators for a wide range of plants in the New World (and, historically, possibly in the Old World – see this post from 2014: There were hummingbirds over the White Cliffs of Dover).  During the last decade I have been involved in some hummingbird-related research with several colleagues, particularly Dr Bo Dalsgaard and Dr Stella Watts, and it’s generated some really interesting findings about the biogeography, macroecology, and interactions with plants of these most elegant of birds.

The latest installment of this work is a test of some ideas relating to the vulnerability of hummingbirds on islands to the extinction of their plant partners.  It’s just been published and the reference is:

Dalsgaard B., Kennedy J.D., Simmons B.I., Baquero A.C., Martín González A.M., Timmermann A., Maruyama P.K., McGuire J.A., Ollerton J., Sutherland W.J. & Rahbek C. (2018) Trait evolution, resource specialization and vulnerability to plant extinctions among Antillean hummingbirds. Proceedings of the Royal Society series B (in press)

Here’s the abstract:

Species traits are thought to predict feeding specialization and the vulnerability of a species to extinctions of interaction partners, but the context in which a species evolved and currently inhabits may also matter. Notably, the predictive power of traits may require that traits evolved to fit interaction partners. Furthermore, local abiotic and biotic conditions may be important. On islands, for instance, specialized and vulnerable species are predicted to be found mainly in mountains, whereas species in lowlands should be generalized and less vulnerable. We evaluated these predictions for hummingbirds and their nectar-food plants on Antillean islands. Our results suggest that the rates of hummingbird trait divergence were higher among ancestral mainland forms before the colonization of the Antilles. In correspondence with the limited trait evolution that occurred within the Antilles, local abiotic and biotic conditions—not species traits—correlate with hummingbird resource specialization and the vulnerability of hummingbirds to extinctions of their floral resources. Specifically, hummingbirds were more specialized and vulnerable in conditions with high topographical complexity, high rainfall, low temperatures and high floral resource richness, which characterize the Antillean Mountains. These findings show that resource specialization and species vulnerability to extinctions of interaction partners are highly context-dependent.

As always I’m happy to send a PDF to anyone who drops me an email.

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Filed under Biodiversity, Birds, Mutualism

Can pollinators survive sudden changes in the weather?

Snow-Warm garden comparison

Just how pollinators cope with sudden changes in the weather early in the season is a bit of a mystery.  Take 2018 as an example; my wife Karin spotted the first queen bumblebee in the garden on 6th January, investigating a camellia flower just outside the kitchen.  Over the course of the next few weeks I saw a few more at various sites, plus occasional hibernating butterflies such as the red admiral. The various social media outlets were reporting similar things, it looked as though we were going to have an early spring.

Then at the end of February “The Beast from the East” hit the UK, a weather system from Siberia that brought some of the coldest weather and heaviest snow the country had experienced for several years.  That persisted for over a week then things got much milder.  On 16th March I was in the garden and spotted the first male hairy-footed flower bee of the year, plus a mining bee (Andrena sp.), and a brimstone butterfly, and a queen bumblebee, and a red admiral.  Great I thought, spring really is here!  The next day it snowed.  A “Mini Beast From the East” had arrived, rapidly: the two pictures above making up the composite view of our garden were taken two days apart.

What happened to all of those insects I saw? Were they killed by the cold weather?  Or did they survive?  We have no firm data to answer that question – as far as I’m aware no one has ever tagged early emerging pollinators and followed their progress (I could be wrong – please let me know if I am).  It would make an interesting, though labour intensive, project but could be done using non-toxic paint of various colours to mark the insects.

I suspect that some of the pollinators I saw were killed, but most were not and simply went back into hibernation for a short period, hunkering down in safe, sheltered spots.  That makes much more evolutionary sense: any insects in the UK that cannot survive sudden changes in the weather would have gone extinct long ago.  Another clue to support this idea is the fact that plants in flower early in the season, and in some cases the flowers themselves, usually survive the cold weather and come back as if nothing had happened.  If the flowers can do it, and they have to stay where they are, surely the mobile pollinators can also do it?

As always I’d be interested in your thoughts on this topic, feel free to comment.  And while we wait for the UK to thaw, here’s some topical and rather catchy music to listen to – The Beelievers singing “Mr Gove”.

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Filed under Bees, Biodiversity, Butterflies, Gardens, Pollination, Urban biodiversity

Mini Bee Symposium – University of Northampton – 13th March 2018

All speakers 20180313_172553_preview

No, not a symposium about tiny Anthophila, but a small get together to discuss bee-related research.  One of the pleasures of my job is hosting visiting scientists from around the world and at the moment I am playing host to three colleagues here in Northampton.   Dr Pablo Gorostiague from the National University of Salta in Argentina is working with me as a visiting postdoc for six months, whilst from the Institute of Zoology at the Chinese Academy of Sciences we have Prof. Chao-Dong “CD” Zhu and Dr Michael Orr here for three days.

So in honour of these visitors, and to introduce them to a wider range of UK bee researchers (some of whom they had corresponded with but never met) I thought it would be fun to organise an informal symposium where people who are (reasonably) nearby could come and present recent bee -related research.

So it was that yesterday a group of about 20 of us spent a great afternoon together listening to 10 short talks.  Here are the presenters and a short description of their presentations:

Steven Falk (independent consultant) discussed “Breaking down barriers to bee identification in Britain” and explained the philosophy behind the structure of his recent Field Guide to the Bees of Great Britain and Ireland.

Stella Watts (Universities of Northampton and Haifa) described her work as a postdoc in Israel examining the structure of plant-pollinator networks centred around some endemic irises.

Chris O’Toole (University of Oxford) dealt with an intriguing phenomenon of what appears to be age-related senility in some Osmia spp.

Pablo Gorostiague told us about his work on bee (and other) pollinators of cacti in his native Argentina.

Ratheesh Kallivalappil (University of Lincoln) discussed his PhD work looking at the decline of global pollinator biodiversity in the Anthropocene.

After a tea break, Stephanie Maher (Anglia Ruskin University) described her PhD work on the nesting ecology of solitary bees in the UK, including a very successful citizen science project.  She argued persuasively for a national database of bee nesting sites.

CD Zhu discussed how modern omics approaches could be integrated into research programmes for understanding the phylogenies and interactions of large clades of species.

Michael Orr talked about the nesting behaviour of some solitary bees of SW North America, and I was surprised to learn that some species can remain in their nests for up to four years before emerging.

In a spontaneous, unscheduled talk Sam Gandy (Universities of Aberdeen and Sussex) told us about research he was involved with that aimed to assess competition between honey bees and bumblebees foraging on lavender.  He did a great job considering he’d not seen the presentation previously, it was emailed to him during the tea break!

Finally I talked about some of our ongoing work assessing the spatio-temporal stability of pollination of an endemic plant by endemic bees in Tenerife.

Following a photo call for all the speakers (see above) we decamped to a local hostelry for beer and food.  Al-in-all a great day of science and networking.  Thanks to all of the speakers and the audience for taking part!

Here are a few more images from the day:

Michael Orr 2018-03-13 16.08.15_preview

Michael Orr in action (I helped to cut that hair!)

Chris OToole 2018-03-13 13.44.37_preview

Chris O’Toole and some of his senile bees

Stella 2018-03-13 13.24.34_previewStella Watts is a blur when presenting her work!

There’s a lot more images on Twitter if you search for #MiniBeeSymposium

 

 

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Filed under Bees, Biodiversity, University of Northampton