Category Archives: Biodiversity

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 6^th 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 16^th 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”.

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

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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_preview Stella Watts is a blur when presenting her work!

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

Plant-pollinator networks in the tropics: a new review just published.

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As an ecologist who has carried out field work in the temperate zone (UK), the subtropics (Tenerife and South Africa) and the tropics (parts of South America, Africa and Australia) I’ve always found the idea that the study of ecology can be divided into “tropical” and “non-tropical” a bit odd. It’s as if the way that the natural world works somehow changes at about 23 degrees north or south of the equator, making things “different” around the equator. The tropics are a very special, diverse place, it’s true, but so are many places outside the tropics.

With this in mind I was pleased when I was asked by some of my Brazilian colleagues to contribute to a chapter in a new book entitled Ecological Networks in the Tropics. It was an opportunity to review what is known about plant-pollinator networks in the tropics and the ways in which they are very similar to such networks at lower latitudes. Here’s the details of the chapter, followed by the abstract. If anyone wants a copy please drop me an email:

Vizentin-Bugoni J, PKM Maruyama, CS Souza, J Ollerton, AR Rech, M Sazima. (2018) Plant-pollinator networks in the tropics: a review. pp 73-91 In Dáttilo W & V. Rico-Gray. Ecological networks in the Tropics. Springer.

Abstract:

Most tropical plants rely on animals for pollination, thus engaging in complex interaction networks. Here, we present a global overview of pollination networks and point out research gaps and emerging differences between tropical and non-tropical areas. Our review highlights an uneven global distribution of studies biased towards non-tropical areas. Moreover, within the tropics, there is a bias towards the Neotropical region where partial networks represent 70.1% of the published studies. Additionally, most networks sampled so far (95.6%) were assembled by inferring interactions by surveying plants (a phytocentric approach). These biases may limit accurate global comparisons of the structure and dynamics of tropical and non-tropical pollination networks. Noteworthy differences of tropical networks (in comparison to the non-tropical ones) include higher species richness which, in turn, promotes lower connectance but higher modularity due to both the higher diversity as well as the integration of more vertebrate pollinators. These interaction patterns are influenced by several ecological, evolutionary, and historical processes, and also sampling artifacts. We propose a neutral–niche continuum model for interactions in pollination systems. This is, arguably, supported by evidence that a high diversity of functional traits promotes greater importance of niche-based processes (i.e., forbidden links caused by morphological mismatching and phenological non-overlap) in determining which interactions occur, rather than random chance of encounter based on abundances (neutrality). We conclude by discussing the possible existence and direction of a latitudinal gradient of specialization in pollination networks.

XI International Symposium on Pollination, Berlin, April 16th -20th, 2018

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From the organisers:

Dear Pollination Biologists,

The International Commission for Pollinator-Plant Relationships (ICPPR) invites you to attend, and possibly submit abstracts for. the XI International Symposium on Pollination TO BE HELD IN BERLIN, GERMANY, APRIL 16-20 2018.

Please take advantage of the early-bird registration opportunity.

The deadline for Abstract submissions is MARCH 1ST, 2018

MORE DETAILS AT:

http://www.icppr.com/xi-international-symposium-on-pollination.html

I HOPE TO SEE YOU IN BERLIN!

Carlos H. Vergara

CHAIR OF THE ORGANIZING COMMITTEE

Metaphors in oak: my Images of Research entry for 2018

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Metaphors in oak.png

The Annual University of Northampton “Images of Research” competition has been running for 5 years and this year’s event has seen a bumper entry of 38 images with accompanying text in fewer than 150 words (including one from our Vice Chancellor).

I think that I’ve entered an image every year – this is from 2016 – and you can see my entry from this year above. It’s called “Metaphors in oak” and here’s my 150 words – perhaps a little fanciful in retrospect, but it’s what the photo said to me at the time:

“This photograph was taken on a recent field trip to Cannock Chase in Staffordshire. I was drawn to the colours and textures of this fallen oak branch as a piece of natural art, but also to its ecological significance. The bark has been attacked by insects then decomposed by fungi and bacteria, leaving behind the wooden core of the branch, which has subsequently been colonised by lichens and mosses. Decay, recycling, colonisation, biodiversity: fundamental ecological patterns and processes. But, with a little imagination, there are also metaphors for research to be seen in this picture. The growth patterns of the wood seem to flow, and in it we can envision a journey of both smooth waters and turbulent times. The diversity of organisms captured in the image reminds us of the varied experiences we can expect during research, not all positive, but all adding to the colour and texture of our lives. What does this image say, and what metaphors does it reveal, to you?”

Here’s a link to the exhibition catalogue and to the online voting system – well worth browsing through to see the range and diversity of research being carried out at our university.

Big Garden Birdwatch – our first six years of data

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Big garden bird watch

This morning I spent an hour gazing out of our bedroom window with a coffee, a notebook, and a pair of binoculars. Not sure what the neighbours opposite us thought I was doing but I was happy – this weekend is the RSPB’s Big Garden Birdwatch! I’ve taken part in it every year since Karin and I moved into our present house in February 2012, and I thought it was time to show the results to date.

As you can see in the graph above, for the first couple of years there were relatively few birds (only 6 species in 2013, 8 in 2014). Then in 2015 it jumped to 15 species, including some that I’ve not recorded in the garden since such as Lesser redpoll. Two reasons for this sudden increase I think. First of all, January 2015 was particualrly cold which meant that more birds were moving into urban areas looking for food and a little more warmth. But secondly, and the reason why higher bird diversity has been maintained since then, is that we’ve been developing the garden and planting more shrubs, small trees, etc.

So since 2012 we’ve gone from this:

2012-02-22 10.19.23

To this:

The garden 20180127_114638.png

This planting and development of the garden has been good for other wildlife including bees, butterflies and other pollinators, as I’ve recounted a number of times. So here’s a close up from last summer just to remind us that, on this grey, drizzly January day, spring is not so far away:

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Of course you don’t need to have a garden to take part in the Big Garden Birdwatch – the RSPB also accepts data from surveys of public parks and green space. In fact tomorrow morning I’m leading a group of residents around our local park, The Racecourse, to do just such a survey.

Right, must go and upload this years data to the RSPB’s site.

Split the kipper: snowfall thoughts of breakfast, fish and childhood games

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Kipper 2018-01-21 10.39.16.png

Karin and I had kippers for breakfast this morning, a satisfying and warming treat on this cold Sunday as we watched the snow fall into the garden, softening the edges and hedges:

Snow in the garden 2018-01-21 11.20.48.png

I do like a nice kipper! Smoking fish to make it last longer has been repeatedly discovered and transmitted as an idea across cultures, and represents a fascinating intersection where wild biodiversity meets human ingenuity. The north east of England, where I grew up, has a great and ancient tradition of smoking herrings to preserve a portion of the catch, a practice that may have originated with the Vikings who colonised that part of the country over one thousand years ago.

Of all of the North Sea’s edible biodiversity I feel most comfortable eating herring; although there were issues with over-fishing in the 1960s and 70s, current stocks look to be being managed sustainably. The most up to date information I’ve found is in a Norwegian government report from which I took this graph:

Kippers have had subtle, but interesting, influences on culture, spawning phrases, songs and games. To be “done up like a kipper”* is to be taken advantage of by someone or bamboozled, whilst a “kipper tie” is a fashion hangover from the 60s and 70s, named for its broad proportions. Of course Supertramp sang about having kippers for breakfast, particularly in Texas “cos everyone’s a millionaire”. That strikes me as an odd line as herrings (in whatever form) have always been considered a cheap dish. Though I suppose importing them from Craster to Dallas could be quite expensive.

Back to the north east and my childhood, where we played a game called “Split the Kipper”. This involved standing opposite a friend on a grassy field and taking it in turns to throw a knife near to your opponent’s foot. If it stuck into the ground then your opponent had to slide their foot to that point. This continued until one of you had your legs so far apart that you fell over – the kipper had been split! Not the safest game for kids but I never knew anyone to get injured playing it. Like all the best games the point was not just to win but to win beautifully: inching your adversary’s legs apart with accurate knife throws gradually ramped up the tension of the game. I wonder where the game originated? Is it too fanciful to imagine that it was brought over by the Vikings?

The snow is still falling – wonder what’s for lunch….?

*Whatever you do, don’t search the Urban Dictionary for the definition of the word “kippered”….

Something for Blue Monday – the only known blue flowered asclepiad

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Tweedia caerulea - OBG 2014-11-06 11.33.14

Today is Blue Monday – reckoned to be the most depressing day of the year, though I’m in a very good mood: just back from a great 9am seminar with my final year students taking the Biodiversity & Conservation module. They presented some really interesting, diverse and thought provoking papers as part of their assessment for this module; it’s a great group to teach.

But if you are suffering from the blues this morning, here is a photograph to cheer you up. As far as I am aware Tweedia caerulea (also known as Oxypetalum coeruleum) is the only known blue flowered asclepiad (that’s to say, a member of the family Apocynaceae subfamily Asclepiadoideae – what used to be the family Asclepiadaceae*).

No one is sure why blue is such a rare colour within the asclepiads (and indeed the Apocynaceae as a whole) and it may be connected to the pollination system of this plant. However we don’t know what pollinates Tweedia caerulea in the wild so it’s hard to test that idea; other species within this group are variously pollinated by wasps, bees, flies, moths, etc. Truly blue flowers (as opposed to some shade of purple or violet) are relatively uncommon generally amongst the flowering plants and the source of much interest and excitement in those groups where they do occur, for example the Himalayan Poppies (Meconopsis).

Tweedia caerulea is easy to grow from seed but not so easy to get through the winter in the UK, so in the past I’ve grown it as an annual in the garden. Apart from the colour, one of the other reasons I like this plant is that it’s named after the 19th century plant collector John Tweedie whose life I’ve been researching over the past 20 years or so – see this paper for example.

*The asclepiads are my favourite group of plants, and one that I’ve published quite a bit of research on, so I was a bit miffed when the taxonomic rank of the family was relegated to subfamily. But it makes evolutionary sense and now gives me a much larger family of plants on which to research, so every cloud etc. etc.

Local and regional specialization in plant–pollinator networks: a new study just published

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Euphorbia canariensis pollinators 2016-04-29 17 58 00

A fundamental feature of the natural world is that no species exists in isolation: all organisms interact with other organisms during their lives. These interactions take many forms and the outcome varies with the type of interactions. For example predator-prey interactions are clearly negative for the prey species, but positive for the predator. Other interactions result in positive outcomes for both species, including relationships between pollinators such as bees, birds and flies, and the flowers that they pollinate. An important feature of such interactions is how specialized or generalized it is; that is, how many different pollinators are actually involved in pollinating a particular type of flower, or how many types of flower does a specific pollinator visits.

In a newly published study, I have collaborated with colleagues from Denmark and Brazil to assess how local specialization (within a community) relates to regional specialization (across communities) using two separate data sets from the Brazilian rupestrian grasslands and Canary Island/North African succulent scrub vegetation.

Here’s the citation with a link to the paper (drop me a line if you can’t access it and need a PDF):

Carstensen, D.W., Trøjelsgaard, K., Ollerton, J. and Morellato, L.P.C. (2017) Local and regional specialization in plant–pollinator networks. Oikos (in press) doi:10.1111/oik.04436

The abstract is as follows:

“Specialization of species is often studied in ecology but its quantification and meaning is disputed. More recently, ecological network analysis has been widely used as a tool to quantify specialization, but here its true meaning is also debated. However, irrespective of the tool used, the geographic scale at which specialization is measured remains central. Consequently, we use data sets of plant–pollinator networks from Brazil and the Canary Islands to explore specialization at local and regional scales. We ask how local specialization of a species is related to its regional specialization, and whether or not species tend to interact with a non-random set of partners in local communities. Local and regional specialization were strongly correlated around the 1:1 line, indicating that species conserve their specialization levels across spatial scales. Furthermore, most plants and pollinators also showed link conservatism repeatedly across local communities, and thus seem to be constrained in their fundamental niche. However, some species are more constrained than others, indicating true specialists. We argue that several geographically separated populations should be evaluated in order to provide a robust evaluation of species specialization.”

This is what those two different habitats look like:

If you would like more information on plant-pollinator networks, including details of an edible game for Christmas (!), follow this link to the standingoutinmyfield blog.

Pollinators, flowers, natural selection and speciation: a virtual conference