Category Archives: Urban biodiversity

First, do no harm! The fundamental rule of creating pollinator habitat that you need to know

I had an interesting conversation with a landscape architect on Wednesday who was asking for some advice about creating urban habitat for pollinators. The plan was to strip turf from under the trees in a city greenspace in order to put in some flowering plants as nectar and pollen sources. I often get asked about this, not only by landscape architects, but by professional gardeners, park committees, local residents groups, and so forth. My initial advice, following the Greek physician Hippocrates, is always the same:

“First, do no harm.”

Hippocrates was of course speaking to doctors and saying: before you intervene in a patient’s health, make sure you are not making things worse for them.

So what do I mean by this? Why is it relevant to pollinators?

Well, in the case of the discussion from earlier this week, the team had no idea if there were ground nesting bees such as Andrena spp. in the area where they planned to strip the turf. Stripping the turf would likely have destroyed any nests, or at least prevented the bees from emerging, particularly if a thick mulch was applied to the area. There were also suggestions of using glyphosate to kill off the grass, though I certainly advised against it: by coincidence a meta-analysis by Lucas Battisti and colleagues was published this week showing categorically that glyphosate is toxic to bees. Imagine spraying it over an area that has a colony of one of the ground-nesting solitary species? Or where queen bumblebees might be hibernating? Queen Bombus spp. often hibernate close to the base of trees – see D.V. Alford’s classic 1969 study of bumblebee hibernation.

It’s not only pollinators that could be harmed by starting work without appropriate surveys: even unpromising-looking municipal grassland, for example in parks, can harbour a significant diversity of plants that are being suppressed by too-frequent mowing. Mow less often and they will flower, producing nectar and pollen for pollinators, then later seeds for birds.

Sometimes you can do more by doing less.

One of the things that I stress in my book Pollinators & Pollination: Nature and Society, is that habitat creation for pollinators is about much more than just planting wild flower meadows and putting up some bee hotels. It needs forethought about what is on a site already, and what may be destroyed by the proposed actions. There also needs to be a consideration of the wider landscape context in which the proposed site is situated, and whether it is providing some of the other things that pollinators need to complete their life cycles each year. The diagram above is from my book and I refer to it as the “Requirements of Pollinators Triangle”. Because pollinators are so diverse in their natural histories, no one site can hope to provide everything that they all need. However there are some general principles that I present in the book.

If you’d like to know more about any of this, or need advice, or to enquire about the training that I offer, please do get in touch via my Contact page.

Online talks and training: here’s a selection of what I offer

Over the past few months I’ve done a large number of online talks for a variety of audiences, including natural history and gardening societies, beekeeping groups, private companies, university estates departments, and ecological consultancies. I thought it would be useful to provide a list of what I offer, with a short description. All talks are accessible and understandable to a broad audience, and can be tailored to the individual needs of the group:

Pollinators & Pollination: Nature and Society is an introduction to the importance of pollinators and the pollination services that they provide to both wild and crop plants. The name, of course, reflects that of my recent book.

The Politics of Pollination is an account of how society (governments, organisations and individuals) has responded to the current “pollination crisis” (if that’s what it actually is…)

Bees in Cities: an Introduction to Urban Pollinators focuses on the positive roles that urban environments can play for pollinators, and the potential threats of city living.

Pollinators in Gardens gives practical advice on how to make your garden “pollinator friendly”.

Pollinator Conservation: Threats and Opportunities describes how and why pollinators are declining and what we can do about it at the individual and societal level.

Habitat Creation and Management for Pollinators gives an introduction to how NGOs, estates departments, consultancies, and so forth, can effectively support pollinators in ways that go beyond just planting flowers and putting up a few “bee hotels”.

To Be a Flower is an introduction to how flowers function and the ways in which they manipulate the behaviour of their pollinators to ensure reproduction.

Darwin’s Unrequited Isle: a Personal Natural History of Tenerife describes some of the field work that we’ve been doing on this most fascinating of the Canary Islands.

Biodiversity: What Is It and Why Should We Care? gives a very general overview of the topic of biodiversity and ecosystem services.

Talks typically last for around 50 minutes, following which I’m happy to answer questions and discuss any issues that have arisen. I also offer a half- or full-day of training for those organisations that need more depth, for example ecological consultancies. Note that I charge for all of my talks and training. If you would like to enquire about any of this, please use the form on the Contact page.

Plant-pollinator networks in Australian urban bushland remnants are not structurally equivalent to those in residential gardens – a new study just published

Towns and cities are ecologically complex environments where nature finds a home in all sorts of places, including both highly artificial gardens created by people, and the fragments of natural environment left behind when developments are built. In a new study that I’ve co-authored with Australian researcher Kit Prendergast we’ve for the first time compared and contrasted the pollinators, and the plants that they visit, in urban settings in the the biodiversity hotspot of Western Australia. Full disclosure: the field work was all done by Kit as part of her PhD. I just acted as an “adopted supervisor” (her words!) to help with data analysis and writing up of the work.

I think that it’s a great study, not least because it really highlights just how different gardens are to remnant natural vegetation. If we are to maintain the maximum possible pollinator diversity, and associated pollination services, we need to retain as much remnant vegetation as possible when designing and building new developments. Gardens alone are not enough.

The study details are:

Prendergast, K.S. & Ollerton, J. (2021) Plant-pollinator networks in Australian urban bushland remnants are not structurally equivalent to those in residential gardens. Urban Ecosystems

The abstract is below; if you’d like a PDF of the paper please use the form on the Contact page.


Urbanisation is a prominent and increasing form of land-use change, with the potential to disrupt the interactions between pollinators such as bees and the flowering plants that they visit. This in turn may cause cascading local extinctions and have consequences for pollination services. Network approaches go beyond simple metrics of abundance and species richness, enabling understanding of how the structure of plant-pollinator communities are affected by urbanisation. Here we compared pollination networks between native vegetation (bushland) remnants and residential gardens in the urbanised region of the southwest Australian biodiversity hotspot. Across fourteen sites, seven per habitat, plant-bee visitor networks were created from surveys conducted monthly during the spring-summer period over two years. Extinction slope (a measure of how extinctions cascade through the network), and network robustness and nestedness were higher for bushland remnants, suggesting that networks in bushland remnants had greater functional integrity, but if disrupted, more cascading extinctions could occur. In contrast, niche overlap between pollinators was higher in residential gardens, suggesting greater competition for resources. Most species-level properties did not differ between habitats, except for normalised degree, which was higher in bushland remnants. In conclusion, it appears that pollination networks in managed residential gardens are not structurally equivalent with those in bushland remnants. This has implications for conservation of wild bee assemblages in this biodiversity hotspot, and suggests removal of remnant native vegetation for residential development could disrupt the integrity of plant-pollinator assemblages.

Finally, a physical copy of my book!

Yesterday I was delighted to finally receive an advance copy of my book Pollinators & Pollination: Nature and Society! It’s been over three years in the writing and production, much longer than I had anticipated. But, as I describe in its pages, the book is the culmination of >50 years of experience, study and research. So perhaps three years isn’t so bad…

If you’re interested in buying a copy you can order it direct from Pelagic Publishing and from most of the large online booksellers. Let me know what you think.

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.

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



Biodiversity, plant-pollinator interactions, and the UN’s Sustainable Development Goals

In the past couple of weeks I’ve delivered two presentations at virtual conferences. The first was at a Global Sustainability Summit run by Amity University, one of our partner institutions in India. The second was at the University of Northampton’s own internal research conference. Both of these focused on pollinators, as you might imagine, but they also referred to the United Nations’ Sustainable Development Goals (SDGs). The 17 SDGs are being increasingly used as a framework for promoting the importance of biodiversity to human societies across the globe, and I’m seeing them referred to more and more often in studies and reports about pollinator conservation. That’s great, and I’m all in favour of the SDGs being promoted in this way. However I wanted to highlight a couple of aspects of the SDGs that I think are missing from recent discussions.

The first is that pollinators, and their interactions with plants, are often seen as contributing mainly to those SDGs that are directly related to agriculture and biodiversity. Here’s an example. Last week the European Commission’s Science for Environment Policy released a “Future Brief” report entitled: “Pollinators: importance for nature and human well-being, drivers of decline and the need for monitoring“. It’s a really interesting summary of current threats to pollinator populations, how we can monitor them, and why it’s important. I recommend you follow that link and take a look. However, in the section about relevant, global-level policies, the report highlights “the UN Sustainable Development Goals (SDGs) – especially regarding food security (‘zero hunger’) and biodiversity (‘life on land’).

I think this is under-selling pollinators and pollination, and here’s why. First of all, as we pointed out in our 2011 paper “How many flowering plants are pollinated by animals?”, approaching 90% of terrestrial plants use insects and vertebrates as agents of their reproduction and hence their long-term survival. As we showed in that paper, and a follow up entitled “The macroecology of animal versus wind pollination: ecological factors are more important than historical climate stability“, the proportion of animal-pollinated plants in a community varies predictably with latitude, typically from 40 to 50 % in temperate areas up to 90 to 100% in tropical habitats. Now, flowering plants dominate most terrestrial habitats and form the basis of most terrestrial food chains. So the long-term viability and sustainability of much the Earth’s biodiversity can be linked back, directly or indirectly, to pollinators. That’s even true of coastal marine biomes, which receive a significant input of energy and nutrients from terrestrial habitats.

Biodiversity itself underpins, or directly or indirectly links to, most of the 17 SDGS; those that don’t have an obvious link have been faded out in this graphic:

The underpinning role of biodiversity, and in particular plant-pollinator interactions, on the SDGs needs to be stated more often and with greater emphasis than it is currently.

The second way in which I think that some writers and researchers in this area have misconstrued the SDGs is that they seem to think that it only applies to “developing” countries. But that’s certainly not the way that the UN intended them. ALL countries, everywhere, are (or should be) “developing” and trying to become more sustainable. To quote the UN’s SDG website:

“the 17 Sustainable Development Goals (SDGs)….are an urgent call for action by all countries – developed and developing – in a global partnership.”


“the SDGs are a call for action by all countries – poor, rich and middle-income – to promote prosperity while protecting the environment.”

I interpret this as meaning that “developed” countries need to consider their own future development, not that they only have to give a helping hand to “developing” countries (though that’s important too). Just to drive this home, here’s a recent case study by Elizabeth Nicholls, Dave Goulson and others that uses Brighton and Hove to show how small-scale urban food production can contribute to the SDGs. I like this because it goes beyond just considering the agricultural and food-related SDGs, and also because by any measure, Brighton and Hove is a fairly affluent part of England.

I’m going to be talking about all of this and discussing it with the audience during an online Cafe Scientifique on Thursday 25th June – details are here. I’m also going to be exploring more of these ideas in my forthcoming book Pollinators & Pollination: Nature and Society, which is due for publication later this year. The manuscript is submitted and is about to be copy-edited. The PowerPoint slide which heads this post uses a graphic from that book that sums up how I feel about biodiversity, plant-pollinator interactions, and the UN’s Sustainable Development Goals.

A pollinator to watch out for in your gardens: the Red-girdled Mining Bee – UPDATED

Last week, during one of my lockdown garden pollinator surveys, I spotted a bee visiting Germander Speedwell (Veronica chamaedrys) in the garden that I didn’t recognise. It initially confused me as it looked superficially like a Blood Bee in the genus Sphecodes. However the bee was clearly collecting pollen, which Sphecodes spp., being cleptoparasites, don’t do. A quick check in Steven Falk’s Field Guide to the Bees of Great Britain and Ireland and a look at Steven’s Flickr site, suggested that it was almost certainly the Red-girdled Mining Bee (Andrena labiata), which is frequently associated with Germander Speedwell.

I posted this video on Twitter and Steven kindly confirmed my identification:

The Red-girdled Mining Bee is considered “Nationally Scarce” and it has a scattered and southerly distribution, as you can see from the map above, which is from the National Biodiversity Network Atlas account for the species. It’s only recorded from about half a dozen sites in Northamptonshire according to Ryan Clark, the County Bee Recorder. However Steven tells me that it’s being seen more and more frequently in gardens, and indeed just the other day Sarah Arnold, who is also carrying out surveys, emailed me to say that she had spotted it in her garden in Kent.

So this is a bee that’s definitely one to look out for, especially if you have Germander Speedwell growing.

UPDATE: I should of course have also given a link to the BWARS account for this species, and mentioned that confirmed or suspected observations can be uploaded to iRecord.

Garden plant-pollinator surveys: progress so far

The network of pollination ecologists and insect specialists who have confirmed that they are surveying plant-pollinator networks in their gardens now stands at 50. As the map above shows, most are in the UK, Ireland and mainland Europe, but the Americas are also becoming well represented, we have a couple of people surveying in North Africa, and three in Australia. An x-y plot of the coordinates of the gardens shows the spread a little better:

Some people have started to send me data already, which is great; if you’re surveying and haven’t let me know your latitude and longitude, please do so, preferably decimalised – you can convert degrees/minutes/seconds to decimal here:

I’ve managed 13 formal 15 minute surveys so far, plus have a few ad hoc observations that I am keeping separate, and I will be continuing my data collection for the foreseeable future. I’ve started playing with the data as you can see below. This is a plot made using the bipartite package in R, with plants to the left and pollinators to the right. The size of the bars is proportional to the number of pollinators/plants a taxon connects to. In the plants you can immediately see the dominance of apple (Malus domestica) and greengage (Prunus domestica), which attract a wide variety of insects to their flowers. Of the pollinators, the hairy-footed flower bee (Anthophora plumipes) and dark-edged beefly (Bombylius major) are especially common and generalist in their flower visits. It will be really interesting to see how this changes over the season, and how our fruit and vegetables are connected into the wider network via pollinators that they share with the ornamental and native plants.

If you are experienced at surveying pollinators and want to get involved, follow that first link and check out the protocol and FAQs, and please do email me: jeff.ollerton [at]

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.