Category Archives: Moths

A new study shows that even short-tubed flowers can specialise on hawkmoths as pollinators

Of all of the “classical” pollination syndromes, flowers that are hawkmoth pollinated have one of the highest levels of predictability. If a flower is pale in colour, opens at night, is highly scented, and possesses a long tube at the bottom of which is a supply of nectar, there’s a very high likelihood that it’s pollinated by long-tongued hawkmoths (Sphingidae).

Indeed, one of the foundational stories about the development of our understanding of how pollination systems evolve, relates to Charles Darwin, the long-tubed orchid Angraecum sesquipedale and the hawkmoth Xanthopan morganii praedicta.

Fast forward 160 years and we now know that pollination syndromes are more complex than 19th and early 20th century scientists imagined – see my recent book Pollinators & Pollination: Nature and Society for a discussion of this topic. That’s not surprising because, as I point out, we probably have data on the interactions between plants and their pollinators for only about 10% of the estimated 352,000 species of flowering plants. There’s still much to be discovered!

As an example of how our understanding of specialised flower-hawkmoth interactions is developing, consider this recent study that I’ve just published with my Brazilian colleague Felipe Amorim and other collaborators. In it we have shown that, contrary to expectations, a species of Apocynaceae (Schubertia grandiflora) with a relatively short floral tube can specialise on hawkmoths with much longer tongues than we might predict.

The full reference with a link to the study is shown below, followed by the abstract. If you would like a PDF, please drop me a line via my Contact page:

Amorim, F.W., Marin, S., Sanz-Viega, P.A., Ollerton, J. & Oliveira, P.E. (2022) Short flowers for long tongues: functional specialization in a nocturnal pollination network of an asclepiad in long-tongued hawkmoths. Biotropica


Since Darwin, very long and narrow floral tubes have been known to represent the main floral morphological feature for specialized long-tongued hawkmoth pollination. However, specialization may be driven by other contrivances instead of floral tube morphology. Asclepiads are plants with a complex floral morphology where primary hawkmoth pollination had never been described. We detailed here the intricate pollination mechanism of the South American asclepiad Schubertia grandiflora, where functional specialization on long-tongued hawkmoth pollinators occurs despite the short floral tube of this species. We studied two plant populations in the Brazilian Cerrado and recorded floral visitors using different approaches, such as light-trapped hawkmoths for pollen analysis, direct field observations, and IR motion-activated cameras. Finally, using a community-level approach we applied an ecological network analysis to identify the realized pollinator niche of S. grandiflora among the available niches in the pollinator community. Throughout a period of 17 years, long-tongued hawkmoths were consistently recorded as the main floral visitors and the only effective pollinators of S. grandiflora. Flowers rely on highly modified corona and gynostegium, and enlarged nectar chambers, to drive visitors and pollination mechanism. Despite its relative short-tube, network analysis placed S. grandiflora in the module including exclusively long-tongued hawkmoth pollinators and the most phenotypically specialized sphingophilous plants in the community. These results represent the first example of functional specialization in long-tongued hawkmoths in an asclepiad species. However, this specialization is uncoupled from the long floral tubes historically associated with the sphingophily syndrome.

Listen to an interview with me on the Environmental Professional’s Radio podcast!

text and logo over a background picture of a person posing for the camera

I was recently invited to chat about careers and writing and pollinators and pollination with the folks from National Association of Environmental Professionals for their Environmental Professional’s Radio podcast. You can listen to it here:

We covered a lot of ground and it was great fun – thanks for having me!

Global effects of land-use intensity on pollinator biodiversity: a new study just published

Humans affect the land on which they live in many different ways, and this in turn influences local biodiversity. Sometimes this has positive effects on local wildlife: consider the diversity of birds to be found in well-managed suburban gardens, for example. But often the effect is negative, especially when the land is intensively managed or habitats are destroyed, for example via deforestation or urban development.

This is not a new phenomenon – according to a recent study, most of the habitable parts of the planet have been shaped by humans for at least 12,000 years (see Ellis et al. 2021). What is new, however, is the scale and the speed with which land-use is changing, which are far greater than they have been historically. An important question is the extent to which this change in land-use intensity is affecting pollinator diversity in different parts of the world. Over the past 18 months I’ve been collaborating on a project led by Joe Millard (as part of his PhD) and Tim Newbold which uses the Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (PREDICTS) database to address that very question.

A paper from that collaboration is published today in the journal Nature Communications; it’s open access and can be downloaded by following this link.

The study was global in scale and used data from 12,170 sites to assess the affect of land-use intensity on 4502 pollinating species. The findings are really fascinating; highlights include:

  • In comparison to natural vegetation, low levels of land-use intensity can have a positive effect on the diversity of pollinators.
  • For most land categories, greater intensity of land-use results in significant reductions in diversity and abundance of pollinators, however. For example, for urban sites there’s a 43% drop in number of species and a drop in 62% pollinator abundance from the least to the most intensive urban sites.
  • On cropland, strong negative responses of pollinators to increasing intensity are only found in tropical areas, although different taxonomic groups vary in their responses.
  • The latter finding is especially concerning given that: (i) most pollinator diversity is found in the tropics; (ii) the majority of tropical crops are insect pollinated; and (3) tropical agriculture is becoming increasingly intensive and land use is likely to rapidly change in the coming decades.

The full reference for the study, with all authors, is:

Millard, J., Outhwaite, C.L., Kinnersley, R., Freeman, R., Gregory, R.D., Adedoja, O., Gavini, S., Kioko, E., Kuhlmann, M., Ollerton, J., Ren, Z.-X. & Newbold, T. (2021) Global effects of land-use intensity on local pollinator biodiversity. Nature Communications 12, 2902.

The chapter titles for my book: Pollinators & Pollination: Nature and Society

A few people have asked me about what’s covered in my book which is being published by Pelagic and is currently in production. Here’s the chapter titles:


1         The importance of pollinators and pollination                               

2         More than just bees: the diversity of pollinators                           

3         To be a flower                                                                                               

4         Fidelity and promiscuity in Darwin’s entangled bank                 

5         The evolution of pollination strategies                                              

6         A matter of time: from daily cycles to climate change                 

7         Agricultural perspectives                                                                        

8         Urban environments                                                                                  

9         The significance of gardens                                                                    

10      The shifting fates of pollinators                                                            

11      New bees on the block                                                                              

12      Managing, restoring and connecting habitats                                 

13      The politics of pollination                                                                        

14      Studying pollinators and pollination                                                  

As you can see it’s a very wide-ranging overview of the subject, and written to be accessible to both specialists and non-specialists alike. To quote what I wrote in the Preface:

“While the book is aimed at a very broad audience, and is intended to be comprehensible to anyone with an interest in science and the environment, and their intersection with human societies, I hope it will also be of interest to those dealing professionally with plants and pollinators. The subject is vast, and those working on bee or hoverfly biology, for example, or plant reproductive ecology, may learn something new about topics adjacent to their specialisms. I certainly learned a lot from writing the book.”

The book is about 100,000 words in length, lots of illustrations, and there will be an index. My copy editor reckons there’s 450 references cited, though I haven’t counted. I do know that they run to 28 pages in the manuscript, and that’s with 11pt text. All going well it will be published before Christmas.

Pollinators and pollination in the UK: an introductory workshop – 26th August

Jeff WT workshop 2020

The Wildlife Trust for Bedfordshire, Cambridgeshire and Northamptonshire has invited me to run my Introduction to Pollinators and Pollination workshop again this year, but of course it will all be online.  Details for signing up are on the images, or you can follow this link. 

Here’s a description of the workshop:

Pollination of flowers ensures the reproduction of most British wild plants and many of our agricultural crops. This session will provide an introduction to the natural history of pollinators and how they interact with the flowers that they pollinate. The main groups of pollinators will be introduced, with guidance on how to identify them, and their ecology and behaviour will be explored. The session will also consider why conserving these species is so important, followed by a Q and A discussion showing what individuals can do to help ensure their future diversity and abundance.

Get a 30% discount if you pre-order my new book Pollinators & Pollination: Nature and Society


In the next few months my new book Pollinators & Pollination: Nature and Society will be published.  As you can imagine, I’m very excited! The book is currently available to pre-order: you can find full details here at the Pelagic Publishing website.  If you do pre-order it you can claim a 30% discount by using the pre-publication offer code POLLINATOR.

As with my blog, the book is aimed at a very broad audience including the interested public, gardeners, conservationists, and scientists working in the various sub-fields of pollinator and pollination research. The chapter titles are as follows:

Preface and Acknowledgements
1. The importance of pollinators and pollination
2. More than just bees: the diversity of pollinators
3. To be a flower
4. Fidelity and promiscuity in Darwin’s entangled bank
5. The evolution of pollination strategies
6. A matter of time: from daily cycles to climate change
7. Agricultural perspectives
8. Urban environments
9. The significance of gardens
10. Shifting fates of pollinators
11. New bees on the block
12. Managing, restoring and connecting habitats
13. The politics of pollination
14. Studying pollinators and pollination



Pollination ecologists in gardens: protocol and links to other initiatives – UPDATE NUMBER 2

Andrena bicolor

UPDATE: Following conversations with a couple of the participants of the garden surveys, we’ve changed the protocol slightly to make Survey type A more quantitative and to take into account when we get large numbers of individuals all visiting the same plant at the same time – it’s crazy to have a single line for each individual.  Details are in the new spreadsheet which you can down load from here: Ollerton garden surveys 2020

The additions should be self explanatory.  If you are not able to go back to retro-fit the additional data, that’s fine, just use the new spreadsheet format for future surveys: all data are going to be useful!

In the present format the data will be useful for modelling using GLMMs etc., in order to test predictions about which plants, and in which contexts, support the most pollinators.  The data format will need tweaking slightly to make it analysable in bipartite, but that should be fairly straightforward.

If you are taking part in the surveys it would be really useful if you could email me your latitude and longitude as I’d like to start creating a map of where the surveys are happening.

Any questions, send me an email or ask in the comments.


Following up from my last post about ecologists using their gardens to collect standardised data, I’ve had a huge response from pollination ecologists all over the world wanting to get involved.  So to streamline the process I thought that I would put the protocol and updates on my blog.  Just to reiterate, this is really is designed for those who already have some experience of surveying pollinators and flowers.  I didn’t intend this to be a citizen science project, there are plenty of those around at the moment for inexperienced people who want to contribute, for example:

The Pollinator Monitoring Scheme’s  FIT (Flower-Insect Timed) counts:

Kit Prendergast’s “bee hotels” survey:

If anyone wants me to publicise others, let me have the link in the comments below or send me an email.

OK, for those ecologists wanting to survey pollinators and the flowers they are visiting (or not visiting) in their gardens, here’s the protocol:

  1.  There are two types of survey – please do both if possible, it would be good to compare the results from the two approaches; otherwise choose the easiest one for you.
  2. Type A surveys involve regular walks at a steady pace around the garden, recording what insects and other flower visitors are active on particular flowers (and noting the ones they are not visiting).  Make your walks a standard time, proportional to the size of the garden. For example, in our 10m x 20m garden I am doing 15 minute walks, which involves walking the same route one way, then back, pausing to record data.
  3. Type B surveys involve 10 minute focused observations of a patch of flowers of one species, no larger than 0.5m x 0.5m, recording the number of flowers each pollinator visits.
  4. In both cases, identify the flower visitor to the taxonomic level to which you feel confident, e.g. it’s better to use Andrena sp. 1 or Calliphoridae sp. 2 or Diptera sp. 3 rather than guessing.
  5. Record all data plus metadata about your garden on this spreadsheet which has examples of data that I have collected so far.  When you return it, please change “Ollerton” to your own surname : Ollerton garden surveys 2020
  6. Please don’t modify the format of the survey sheets, it will make life very difficult when we collate the data.
  7. Collect data from now until the end of April.  By then we will know whether to continue further data collection.
  8. At the end of the month, send your spreadsheets to me: jeff.ollerton [at]  I will acknowledge receipt of each one, so if you don’t get an acknowledgement it may be that our spam filter has rejected your email, in which case message me on Twitter or comment below.
  9. Finally – please respect local/national restrictions on movements and social isolation: safe safe and keep your community safe.


Here are some Frequently Asked Questions – I will update FAQs as they come in:

Q: What’s going to happen to all of the data?

I think that’s for the pollinator research community to decide.  My feeling at the moment is that in the first instance there should be a data paper that summarises the results and makes the data freely available to everyone.  That would include all data contributors as co-authors, probably under a project name rather than individually.  After that it’s up to individuals and groups to work with the data to address their own research questions.  I know that in the UK there are several PhD researchers who are worried about not being able to collect data this year and who want to contribute to this initiative and use it in their theses.  I’m sure that there are others elsewhere.  As a community it would be great to support these young researchers.

Q: I am not based in the UK, can I still take part?

A: Yes, of course, though check in your local networks to see if anyone is coordinating local efforts.

Q: How do I calculate “Total floral cover” for survey Type B?

A: The idea is to estimate the area covered by all of the patches of the plant in flower across the whole garden, and then add it up to get a total area covered. It is always going to be a rough estimate, but it at least gives us a sense of how abundant the flowers are in your garden.

Q: How do I classify “floral units” for survey Type B?

A: Use the UK POMS approach:

POMS flower heads

Q:  Should I collect weather data?

A: You can certainly add data to another sheet on the spreadsheet if you want to, but the plan is to use data from local weather stations to capture standardised weather information.

Q: Should I collect nectar and/or pollen and/or pollinator behaviour data?

A: Again, collect any data that you have the time and equipment for and add it to a different sheet

Q: My garden has very few flowers and pollinators – can I still take part?

A: Yes, absolutely, we need a range of garden types, from the very large and florally diverse to small window boxes or lawns with just daisies and dandelions..

Q: How long should I survey for, and how many surveys should I do.

A: Try to aim for what you think is a representative assessment of the plant-flower visitor network in your garden.  The idea is that people do as many surveys as they can, as often as they can, given their personal time constraints. I don’t want to dictate to people how to use their time, this needs to be enjoyable as well as useful. As long as we know the sampling effort and floral diversity within the gardens, we should be able to take account of sampling effort in any analyses.

Last year’s mother, this year’s child: cinnabar moths in the garden

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Most summers we have a small colony of cinnabar moths (Tyria jacobaeae) reproducing in the garden.  The garish yellow-and-black caterpillars feed on species of ragwort and we leave a patch of common ragwort (Jacobaea vulgaris) to grow in the lawn.  The caterpillars eat for a few weeks, virtually destroy the ragwort, and in the process accumulate alkaloids from the host plant into their bodies.  This renders them toxic in much the same way as monarch butterflies accumulate toxins from their Asclepias food plants – see my recent post about the Monarchs and Milkweeds workshop.  Hence the stripes to warn birds of their unpalatability.

Ragwort is a much-maligned plant, hated by those with horses and livestock, and subject to a largely hysterical campaign of eradication – see here for example.   However John Clare clearly appreciated its virtues in a poem dedicated to the plant:

Ragwort, thou humble flower with tattered leaves
I love to see thee come & litter gold,
What time the summer binds her russet sheaves;
Decking rude spots in beauties manifold,
That without thee were dreary to behold.

The full text of the poem can be found here.

Once they have fed their fill, the caterpillars dig themselves into the soil to spend twelve months or so underground as pupae, before emerging as gorgeous adult moths, advertising their toxicity with a different colour scheme.

The adults live for a few weeks at most, during which time they feed on nectar, mate, lay eggs and die.  This (unposed) photograph that I snapped on my phone in the garden yesterday just about sums it up: an exhausted mother has laid her last batch of eggs then died, while a nearby young caterpillar munches away on the ragwort.  And so the generations pass.

Cinnabar caterpillars on ragwort

Pollinators, landscape and friends: our recent trip to the Danish island of Sejerø

2018-07-15 11.16.02

This is not the first time I’ve written about the beautiful Danish island of Sejerø – see my post “Why do bumblebees follow ferries?“.  It’s home to our friends Pia and Stephen Valentine (Stephen is the very talented artist who produced the fabulous study of waxwings that Karin commissioned for my birthday last year).  Earlier this month we traveled over to stay with them and to explore some more of the island.  Here are some photos and thoughts from that trip.

Despite the hot, dry weather that northern Europe has been experiencing recently there were pollinators aplenty.  Thistles and knapweeds (both groups from the daisy family Asteraceae) are well known to be drought tolerant and attract a lot of insect interest.  This is a Pantaloon Bee (Dasypoda sp.)  If it was Britain I’d say that it was D. hirtipes, but there are other species on the continent so I can’t be sure.  These bees are well named: the “pantaloons” are found only on the females and are used to collect pollen, especially from Asteraceae.

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I believe that this is the male of this species; note the absence of the pollen-collecting hairs on the rear legs and the yellow face, typical of many male bees:

The flower heads of the knapweeds were highly sought after; on this one, two different bumblebees (Bombus spp.) were competing with two Silver Y moths (Autographa gamma):

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Sometimes the bumblebees got an inflorescence to themselves, though the photobombing Silver Ys were never far away:

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It’s been a good year for the Silver Y, large numbers have migrated northwards from southern Europe and we’ve had lots in our garden too.  On Sejerø they were everywhere, on all kinds of plants: 

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The butterfly is one of the Blues (Lycaenidae), possibly Common Blue (Polyommatus icarus), but again this being Denmark they may have other species that I’m not familiar with.  Note the Silver Y photobombing once more…:


Wild carrot (Daucus carota) was common on the island and always attracts a wide range of flies, wasps and beetles:


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Close to home we found a huge cherry tree laden with the fruits of pollination and collected a couple of kilos for Stephen to make into jam.  Stoning them was messy but fun and a nice opportunity to sit and chat about nature and people:

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I was very impressed with Stephen’s up-cycled general purpose baskets, made from plastic containers he finds on the beach, wire, and lengths of old hosepipe:

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Along the shore another edible plant, Sea Kale (Crambe maritima) was attracting a lot of attention from white butterflies (Pieridae) whose caterpillars feed on this and other members of the cabbage family (Brassicaceae):

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I tried a piece of raw leaf; it tasted ok, salty and a little bitter.  Apparently it’s very nice if you blanch the young leaves.  It’s a distinctive and impressive component of the beach flora:

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Amidst the greens, buffs and browns of the beach landscape we encountered the occasional scarlet of a patch of poppies (Papaver sp.):

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Everywhere on the island we saw evidence of the link between life on land and in the sea, and the cycles and processes upon which that life depends.  Sand martins (Riparia riparia – an apt name – “riparian” refers to the interface between land and water) are common and their nest excavations speed up the return of sediments back to the sea:

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Favoured rocks have been used by gulls and other sea birds for generations, their guano helping to enrich these coastal waters and fueling the primary production of seaweeds and diatoms, which in turn feed other shore life:

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Evidence of human activities was never far away, though, concrete and steel blending with nature:

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Wheat fields merging with the sky:

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Thanks to Pia and Stephen, and of course Zenja, for making this such a wonderful trip and allowing us to join them in exploring their home island:

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Pollinator biodiversity and why it’s important: a new review just published – download it for free


In a new review paper that’s just been published in the Annual Review of Ecology, Evolution and Systematics I have looked at the question of just how diverse the pollinators are, and why pollinator biodiversity is ecologically important and therefore worthy of conservation.  I’ve taken a deep time and wide space approach to this, starting with what the fossil record tells us about when animal pollination evolved and the types of organisms that acted as pollinators in the past (the answer may surprise you if you’re unfamiliar with the recent paleontological literature on this topic).  Some of the most prominent biogeographical patterns have been highlighted, and I have tried to estimate the global diversity of currently known pollinators.  A conclusion is that as many as 1 in 10 described animal species may act as pollen vectors.

As well as this descriptive part of the review I’ve summarised some recent literature on why pollinator diversity matters, and how losing that diversity can affect fruit and seed set in natural and agricultural contexts.  Extinction of pollinator species locally, regionally, and globally should concern us all.

Although I was initially a little worried that the review was too broad and unfocused, having re-read it I’m pleased that I decided to approach the topic in this way.  The research literature, public policy, and conservation efforts are currently moving at such a fast pace that I think it’s a good time to pause and look at the bigger picture of what “Saving the Pollinators” actually means and why it’s so important.  I hope you agree and I’d be happy to receive feedback.

You can download a PDF of the review entitled Pollinator Diversity: Distribution, Ecological Function, and Conservation by following that link.

Pollination ecologists should also note that in this same volume of Annual Review of Ecology, Evolution and Systematics there’s a review by Spencer Barrett and Lawrence Harder called The Ecology of Mating and Its Evolutionary Consequences in Seed Plants.  If you contact those authors I’m sure they’d let you have a copy.