Tag Archives: Science

Biodiversity Net Gain and pollinators – join me for a FREE webinar next Monday!

Biodiversity Net Gain is generating a lot of attention in the UK at the moment, some of it positive*:

“when designed and delivered well, BNG can secure benefits for nature, people and places, and for the economy”

“[BNG is] a game-changer for health and wellbeing”

And some of it extremely negative*:

“Biodiversity Net Gain is a lie but most people without enough ecological knowledge cannot see this & are fooled by the lie”

“[BNG is] a horrible legalistic contrivance, and it means nothing”

Regardless of how you feel about BNG, it’s here to stay, at least for the foreseeable future, and so we need to explore it and understand how (or whether) it can positively improve the state of nature in Britain.

Although I don’t pretend to be an expert on BNG**, I have thought a lot about how it might impact the group that I do have some expertise in, pollinators, and the implications for the pollination services that they provide to wild and crop plants.

Last October I produced a short report that considered the implications of BNG for insect pollinators – you can download a copy from the original blog post, though do be aware that some of the dates I mentioned were later revised by the then government and I have yet to revise the document.

As a follow up to this I have been invited by the Biological Recording Company to lead a one-hour webinar discussing this topic on Monday 28th October at 1pm. It’s free to attend and you can book a ticket by following this link. There’ll be a short presentation (30 minutes or so) followed by a live Q&A.

I hope that some of you can join me!

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*Real quotes, culled from reports and social media.

**Indeed, it’s such a new approach to development and nature conservation, can anybody consider themselves an expert?

What are the limits to pollinator diversity? A new article poses the question

The most globally significant groups of pollinators are well known and have been studied for a long time: bees and wasps, flies, butterflies and moths, birds, bats and beetles are all familiar to those of us with an interest in pollination ecology. However, every few years a new type of pollinator or a novel pollination system is described from nature or from the fossil record, or we add further examples of previously neglected pollinator groups such as cockroaches.

This begs the question: how much is there still to discover? How close are we to describing the full diversity of animals that act as pollen vectors? Can looking at the past help us to predict what we might find in the future? That’s the topic of a Perspective article that I was invited to write for the special issue of the Journal of Applied Entomology on the theme of  The Neglected Pollinators that I mentioned last month. It’s a subject that I’ve thought about a lot over the last few decades and it was great to get an opportunity to air some ideas and speculation.

The article is open access and you can download a copy by following the link in this reference:

Ollerton, J. (2024) What are the phylogenetic limits to pollinator diversity? Journal of Applied Entomology (in press)

Here’s the abstract:

Although huge progress has been made over the past 200 years in identifying the diversity of pollinators of angiosperms and other plants, new discoveries continue to be made each year, especially in tropical areas and in the fossil record. In this perspective article I address the following questions: Just how diverse are the pollinators and what are the phylogenetic limits to that diversity? Which other groups of animals, not currently known to regularly engage with flowers, might be found to be pollinators in the future? Can we predict, from the fossil record and from discoveries in under-researched parts of the world, which animal groups might turn out in the future to contain pollinators? I also discuss why adding to our knowledge of plant–pollinator interactions is important, but also stress that an incomplete knowledge may not be a bad thing if it means that remote, inaccessible and relatively pristine parts of the world remain that way.

Science ceramics – the perfect gift for the geek in your life!

Over at the Dynamic Ecology blog, Jeremy Fox has provided a link to a company called Not Quite Past that uses AI to generate an image for a ceramic tile in the style of Dutch Delftware based on the prompts that you give it. That part is free, but if you wish the company will then manufacture that tile and ship it to you (though there’s a minimum order of 10 tiles).

It reminded me that when I was working in China earlier this year, we visited the extraordinary Museum of Chengjiang Fossils, dedicated to an amazing assemblage of early Cambrian-age animals. This biota is comparable to the more famous Burgess Shale fauna in Canada: both are in excess of 500 million years old, and they share some animals in common.

One such taxon is the genus Anomalocaris, a group of predatory early arthropods, the disarticulated parts of which were originally misidentified as belonging to different animals. It was the late Stephen J. Gould who first brought the story to popular attention in his 1989 book Wonderful Life. I read this when it was first published and had the pleasure of seeing Gould give a lecture about it in Oxford, and the story of Anomalocaris stuck with me. So it was great to see actual fossils of this remarkable animal in China.

Not only did I get to view the fossils, but I was able to buy the plate that’s featured at the top of this post, featuring a hand-painted painted Anomalocaris in a traditional Chinese style. It’s perhaps the most geeky ceramic imaginable, though Jeremy’s Daphnia tile comes a close second!

Here’s some more photos from the Chengjiang Museum, including sculptures of both Anomalocaris and the similarly mis-reconstructed Hallucigenia:

Butterflies, bumblebees and hoverflies can be equally effective pollinators of some plants says a new study

Just after I arrived in Northampton in 1995, I set about looking for suitable local sites for conducting pollination ecology field work for myself and students. The campus on which we were situated at the time was adjacent to an urban park – Bradlaugh* Fields – parts of which were designated as local nature reserves. In the intervening years, data from that area have made their way into a wide range of published studies, including:

I still have data collected during that time that have never been published, but good data are hard won and they may see the light of day at some point. Case in point is that we’ve just published a paper based on data from Bradlaugh Fields, the first of which were collected in 2001!

In this paper we’ve tested how effective hoverflies, butterflies and bumblebees are at pollinating the flowers of a common generalist grassland plant, colloquially called Field Scabious (Knautia arvensis). The expectation was that bumblebees, being generally larger, hairier and more flower-focused than the other groups, would be the most effective at transferring pollen to stigmas. To our surprise, they were not: hoverflies and butterflies performed just as well! In fact we argue that butterflies may be MORE important as pollinators of this plant because they fly further distances between individual plants, rather than hopping between the inflorescences of the same plants, as bumblebees tend to do.

Crucially, the importance of these different groups of pollinators varies enormously as the relative abundance of the insects visiting the flowers differs between seasons. In some years butterflies dominate as pollinators, in other years bumblebees or hoverflies. This is driven, we think, both by fluctuations in the populations of these insects and by the availability of other, more preferred flowers that may bloom at the same time.

The paper is part of a special issue of the Journal of Applied Entomology devoted to The Neglected Pollinators. It’s open access and you can download a copy by following the link in this reference:

Ollerton, J., Coulthard, E., Tarrant, S., Woolford, J., Ré Jorge, L. & Rech, A.R. (2024) Butterflies, bumblebees and hoverflies are equally effective pollinators of Knautia arvensis (Caprifoliaceae), a generalist plant species with compound inflorescences. Journal of Applied Entomology (in press)

Here’s the abstract:

Plant-pollinator interactions exist along a continuum from complete specialisation to highly generalised, that may vary in time and space. A long-held assumption is that large bees are usually the most effective pollinators of generalist plants. We tested this by studying the relative importance of different groups of pollinators of Knautia arvensis (L.) Coult. (Caprifoliaceae: Dipsacoideae). This plant is suitable for such a study because it attracts a diversity of flower visitors, belonging to different functional groups. We asked whether all functional groups of pollinators are equally effective, or if one group is most effective, which has been documented in other species with apparently generalised pollination systems. We studied two subpopulations of K. arvensis, one at low and one at high density in Northampton, UK. To assess pollinator importance we exposed unvisited inflorescences to single visits by different groups of pollinators (butterflies, bumblebees, hoverflies and others) and assessed the proportion of pollinated stigmas. We then multiplied the effectiveness of each pollinator group with their proportional visitation frequency in five different years. For each group we also compared time spent on flowers and flight distance between visits. The relative importance of each pollinator group varied between years, as did their flight distances between flower visits. Butterflies were the best pollinators on a per visit basis (in terms of the proportion of stigmas pollinated) and flew further after visiting an inflorescence. Different measures and proxies of pollinator effectiveness varied between taxa, subpopulations, and years, and no one group of pollinators was consistently more effective than the others. Our results demonstrate the adaptive value of generalised pollination strategies when variation in relative abundance of different types of pollinators is considered. Such strategies may have buffered the ability of plants to reproduce during past periods of environmental change and may do so in the future.

*Named after the estimable local MP and radical Charles Bradlaugh – see my blog post When Charles collide: Darwin, Bradlaugh, and birth control for Darwin Day 2016

Speaking at Oxford Ornithological Society – 11th September

Later this month I’ve been invited by the Oxford Ornithological Society to give a talk about my new book Birds & Flowers: An Intimate 50 Million Year Relationship. The talk will summarise the main themes from the book, particularly the sheer diversity of birds that can act as pollinators, what it means for the ecology and evolution of flowers, why the conservation of such interactions matters, and the cultural significance of bird-flower interactions. I’ll also deal with the question of why Europe is so odd when it comes to the question of birds as pollinators.

The talk is on Wednesday 11th September at Exeter Hall, Kidlington, starting at 7.45 pm; it’s free to society members, and non-members are invited to make a donation. Do come along if you’re in the area!

More details here: https://www.oos.org.uk/programme.php

I’ll bring a few copies of Birds & Flowers and Pollinators & Pollination: Nature and Society if anyone wants to buy a signed book.

Also in the diary are talks at South Leicester Birdwatchers (13th November) and Northamptonshire Bird Club (5th March).

If you represent a birding club or natural history society and wish to book me for a talk, please get in touch via my Contact page.

Don’t forget the blogosphere! A new opinion piece just published

Despite claims to the contrary, the total demise of the ecology blogosphere has not yet occurred. Some of us are still going strong, and others such as Dynamic Ecology and Jabberwocky Ecology have reactivated after a prolonged hiatus. It seems timely, therefore, to revisit the whole notion of ecological blogging, what it’s for, and what bloggers and readers get from it, personally as well as professionally. That’s the purpose of a new opinion piece just published in the Annals of Applied Biology.

The article is part of a special issue of that journal dedicated to the late Prof. Simon Leather, who was both its former Editor-in-Chief and a dedicated blogger. Simon, with his insightful, often very funny, blogging voice on Don’t Forget the Roundabouts, is sorely missed.

The full reference with a link to the journal is below. If anyone needs a PDF, please do ask via my Contact page:

Heinen, R., Duffy, M., Fox, J.W., Heard, S.B., McGlynn, T., Ollerton, J., Rillig, M.C., Saunders, M.E., Millman, C.A. & Azevedo, R.A. (2024) Opinion: Don’t forget the blogosphere. Annals of Applied Biology 185: 124–131

Here’s the abstract:

Communicating results and ideas to a wider audience has been an important, but challenging component of scientists working in an academic environment. Particularly in recent decades, various social media platforms have become increasingly important to facilitate this. In addition, many scientists have used blogging platforms to communicate and discuss their work. Although the online dynamics of science communication are continuously changing, blogging has been used in a remarkably stable form for several decades. For this work, we brought several ecology bloggers to reflect on blogging as a science communication medium. We argue that blogging can be a powerful way to present new ideas and discuss them with a wide audience. Although blogs are not the same as scientific articles, they often serve as the initial brainstorm session. Importantly, we argue that blogs are most effective when bloggers and readers actively engage in conversations. We believe that blogging will be here to stay in science communication because of its unique and independent form of outreach.

Urban bees are often early bees says a new study

The latest paper from Muzafar Sirohi‘s PhD work on urban solitary bees has just been published in the journal Zoodiversity, a publication of the National Academy of Sciences of Ukraine. In this paper we looked at how the flight periods of urban populations of bees differ from those in surrounding nature reserves and other “natural” settings. One of the most interesting findings is that urban bees tend to emerge earlier, and be active longer, than their rural counterparts. The quote the study:

“We observed a substantial effect of urban microclimate on bee flight periods. A total of 153 individuals of nine bee species were recorded one to nine weeks before or after their expected flight periods. In contrast, only 14 individuals of four species were seen at unusual flight periods in nature sites.”

In my book Pollinators & Pollination: Nature and Society I discussed the importance of towns and cities for supporting pollinator populations, and conversely how important those populations are for urban food production. Likewise, in Birds and Flowers: An Intimate 50 Million Year Relationship I have a chapter entitled “Urban flowers for urban birds”. The relationship between our built environment and pollinators is a fascinating topic, but there’s still much we don’t understand about how these insects and vertebrates respond behaviorally to urbanisation. Are they adapting in an evolutionary sense, or simply responding flexibly to the different conditions that cities impose on their biologies? Will future climate change make towns and cities uninhabitable for these animals? Hopefully our paper will stimulate further work on these and other topics.

Here’s the full reference with a link to the paper (which is open access):

Sirohi, M. H., Jackson, J., & Ollerton, J. (2024). Comparison of Flight Periods of Solitary and Primitively Eusocial Bees in Urban Environments and Nature Conservation Areas: a Preliminary Report. Zoodiversity 58: 317-334

Here’s the abstract:

Solitary and primitively eusocial bees, an important group of pollinators, have declined in the past few decades. In view of the recent focus on safeguarding pollinating insects, it is vital to understand the basic ecology of species for their conservation, for example their phenologies. We observed the flight periods of solitary and primitively eusocial bees in both the urban core of a large British town and nearby nature conservation areas. The bee surveys were conducted with standardised methods, on warm sunny days from the first appearance of bees in March 2012 and continued until October 2012. This study confirmed that a high number of species are active in the spring season. The emergence dates of species in urban areas and nature sites varied; about 26 of the 35 species were recorded at least one week earlier in urban areas; in contrast, only four species were seen earlier in nature conservation sites. When comparing this with the expected flight periods recorded (largely in nature sites) in the literature, many species were recorded at their expected time. However, a few individuals were recorded after their usual flight activity time, suggesting that the populations were possibly affected by the microclimate in urban areas. More urban phenological data are needed to understand the phenological trends in bees in urban habitats.

Pollination by birds: the curious case of Europe

Earlier this year I was invited by the editor of British Wildlife magazine to write a piece for their Changing Perspectives section about how odd Europe is when it comes to bird pollination. It’s based on one of the chapters in my book Birds & Flowers: An Intimate 50 Million Year Relationship.

If you subscribe to the magazine, it will appear in the August issue, though I’m happy to send a PDF to anyone who doesn’t subscribe (or has not read the book) – use the Contact Page. The main accompanying photograph is by one of my former students, Lisa King, who kindly allowed me to use it.

If osiers are all you know – China Diary 6

It’s very easy to get a fixed idea of what you think a particular group of plants ‘ought’ to look like, based on those that are most familiar to you from where you live. But exploring a good botanic garden always reveals surprises, as far as plant families are concerned. Willows (or osiers) provided me with a great example recently. Based on those that I am familiar with, I thought I had a pretty good idea of what to expect from the family Salicaceae, which includes not just willows (Salix spp.) but also aspens and poplars.

Then you encounter the trunk of a large tree that’s covered in vicious thorns that remind you of the rose family (Rosaceae) and particularly some species of cherries and plums, such as Blackthorn (Prunus spinosa). But it’s a big tree, larger than expected for that group, and the bark in particular doesn’t look right:

Fortunately, being a botanic garden, there’s a helpful label:

Lo and behold, it’s a member of the willow family! A species of Xylosma, quite a large genus of about 100 species, but not one with which I am familiar.

I encountered another example in the Chinese medicinal garden – a species of milkwort (Polygala). The milkworts that are native to Britain are low-growing, herbaceous species, not tall woody shrubs like this P. arillata. The rather legume-like flowers are familiar, but not displayed in these pendant inflorescences, laburnum style:

This wasn’t the biggest surprise of my China trip so far, however – how about these clusters of yellow-ish white, highly fragrant flowers, on a large (15 metre) tree? What family could it belong to?

Again, Rosaceae comes to mind, but it turns out that it’s in the borage or forget-me-not family (Boraginaceae):

Those last two species are a nice example of a general trends in plant families and genera, which often contain smaller, herbaceous species in cooler, more temperate parts of the world and larger, woody species at lower latitudes in the tropics and subtropics. Bamboos (which are of course woody grasses) are a good example – and we have encountered some spectacular specimens in the garden:

Of course there’s also some familiar species, including birds: how many Little Egrets can you spot in this picture?

Exploring botanic gardens are one of my favourite pastimes, it’s always worthwhile and, in the words of an old blog post of mine, Je ne egret rien.

Listen to my interview on the Crime Pays But Botany Doesn’t podcast!

Last week I had the pleasure of chatting for over two hours with Joey Santore for his Crime Pays But Botany Doesn’t podcast series about my two books Plants & Pollinators: Nature and Society and Birds & Flowers: An Intimate 50 Million Year Relationship.

I’m a long-standing fan of his YouTube video channel which Joey describes as “A Low-Brow, Crass Approach to Plant Ecology & Evolution as muttered by a Misanthropic Chicago Italian.”

It was a lot of fun to talk flowers and pollinators with him and although I tried to keep my swearing to a minimum, if you know Joey and his work, you know what you’re in for, so be warned! It’s not for the easily offended.

We had sound issues at a couple of points and note that at 54:20 I made an error, and said “hummingbirds” a couple of times when I meant “sunbirds”. Put it down to a lack of coffee that morning….

Here’s the link: