One of the projects with which I’ve been involved over the last year has been advising on a new book for children about bees and other pollinators, called Can We Really Help The Bees? Written by Katie Daynes and wonderfully illustrated by Róisín Hahessy, it tells the story of what happens when a swarm of bees comes to the window to let a group of children know that they, and their friends the other pollinators, are in trouble. Can they help? Yes they can!
It’s been a real pleasure working with Katie and Róisín on this project for Usborne Publishing and seeing the ideas, text, and illustrations evolve over time. I’ve written a short post over at the Usborne blog with some ideas about how to get children involved in helping the pollinators, and I think that it’s worth repeating one of the things that I wrote: everyone can make a difference to the wildlife around us and no one is too young to be involved!
Because of my involvement with Can We Really Help The Bees? I wasn’t able to include it on my curated list of the best books about bees and other pollinators at the Shepherd site. But it definitely should be on there and is highly recommended!
Recently Phil Stevenson and I advised on an art/science project called Minus Pollinators which considered what a small café menu might look like if there were no pollinators to help produce the many, many fruits and vegetables and nuts that are animal pollinated.
The project is a collaboration between writer and consultant Max Fraser and artist Freddie Yauner. To quote Freddie’s description on his website, the project represents:
A dystopian future in the form of a drinks kiosk where the staples such as coffee, teas, juices, chocolate etc. are no longer available due to pollinator decline…the mobile drinks kiosk acts as an exhibition display, with artworks painted in pollen…and a take-away pamphlet…detailing the importance of insect pollinators for our collective future on this planet.
Minus Pollinators was commissioned as part of a summer-long event called Food Forever at the Royal Botanic Gardens, Kew, after which it goes to the Groundswell festival.
It was a pleasure to work with Max, Freddie and Phil on this because art/science projects are a great way of getting the message across about the importance of biodiversity and the current environmental crisis that we are facing.
In my recent book Pollinators & Pollination: Nature and Society I discussed the current state of our knowledge of how populations of pollinators have changed over time. Although we have some quite detailed data for particular, often charismatic, species or for certain geographic localities or regions, for most species we know almost nothing. As I wrote in the chapter “The shifting fates of pollinators”:
“For most pollinators we are ‘data deficient’, in other words, we don’t know how their populations are performing. They could be doing well, but they may not be”
This is particularly true for those regions for the world that hold the greatest terrestrial biodiversity: the tropics. For the vast majority of species in the tropics we know precious little about trends in their populations and how their distributions have changed over time in the face of wide-scale land transformation and recent climatic shifts. Filling in some of the gaps in our knowledge of Neotropical pollinator distributions is one of its aims of SURPASS2, a collaboration between South American and UK ecologists, and one of several research and outreach projects with which I’m involved.
In a new study that’s come out of that work, led by Rob Boyd from the UK Centre for Ecology and Hydrology, we’ve used the GBIF database to look at the changing distributions of four important groups of pollinators: bees, hoverflies, leaf-nosed bats and hummingbirds. In particular we were interested in understanding the kinds of biases that come with such publicly available data, and whether recent efforts to add data to GBIF has improved our understanding of trends.
Our overall conclusion is that there are significant limitations and biases inherent in all of these data sets even for groups like hummingbirds which one would imagine are well documented by scientists and bird-watching naturalists. In addition, having more data does not necessarily help matters: it can introduce its own biases.
The paper is open access and feely available; here’s the reference with a link:
Aim Aggregated species occurrence data are increasingly accessible through public databases for the analysis of temporal trends in the geographic distributions of species. However, biases in these data present challenges for statistical inference. We assessed potential biases in data available through GBIF on the occurrences of four flower-visiting taxa: bees (Anthophila), hoverflies (Syrphidae), leaf-nosed bats (Phyllostomidae) and hummingbirds (Trochilidae). We also assessed whether and to what extent data mobilization efforts improved our ability to estimate trends in species’ distributions.
Location The Neotropics.
Methods We used five data-driven heuristics to screen the data for potential geographic, temporal and taxonomic biases. We began with a continental-scale assessment of the data for all four taxa. We then identified two recent data mobilization efforts (2021) that drastically increased the quantity of records of bees collected in Chile available through GBIF. We compared the dataset before and after the addition of these new records in terms of their biases and estimated trends in species’ distributions.
Results We found evidence of potential sampling biases for all taxa. The addition of newly-mobilized records of bees in Chile decreased some biases but introduced others. Despite increasing the quantity of data for bees in Chile sixfold, estimates of trends in species’ distributions derived using the postmobilization dataset were broadly similar to what would have been estimated before their introduction, albeit more precise.
Main conclusions Our results highlight the challenges associated with drawing robust inferences about trends in species’ distributions using publicly available data. Mobilizing historic records will not always enable trend estimation because more data do not necessarily equal less bias. Analysts should carefully assess their data before conducting analyses: this might enable the estimation of more robust trends and help to identify strategies for effective data mobilization. Our study also reinforces the need for targeted monitoring of pollinators worldwide.
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SURPASS2 has been a hugely productive project as you’ll see if you look at the Publications page of the website. There’s much more to come and I’ll report on those research papers as they appear.
Recently I enjoyed chatting with Dr Daniela Scaccabarozzi for the YouTube channel that she runs called Earth To Be. In a wide ranging interview we discussed my recent book, how it came about, some of the things that intrigued me during its research (including a cockroach-pollinated flower!), and the role of people and pollinators in the wider ecosystem. Thanks to Daniela for the invitation to chat! Here’s the link to the interview.
Clearly that’s a very subjective question and everyone has their own view on which books about a particular subject they would recommend! So coming up with a list of just five for the Shepherd book recommendation site was not easy. My list features authors such as Brenda Z. Guiberson, Megan Lloyd, Steven Falk, Dave Goulson, Mike Shanahan and Stephen L. Buchmann, which will hopefully inspire you to read some of these books.
If you think that I’ve missed your favourite from the list, please do comment below. And if you’re an author, consider signing up for Shepherd and curating your own list, they’ve been really helpful and it’s a useful service for readers and authors.
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).
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:
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.
Yesterday Karin and I took to our bikes and rode south through some very nice, managed beech and oak woodland that runs parallel to the Isefjordenin this part of Odsherred. In was cold but sunny, birds were singing, and we saw the occasional insect on the wing. The kind of day that reminds you that spring is coming fast. On the way back we paused at a small housing development near the former psychiatric hospital at Annebergparken. In an area of disturbed ground I was delighted to see a patch of coltsfoot (Tussilago farfara) in full flower, the dandelion-like inflorescences a beacon to passing bees and flies.
Although it resembles a small dandelion, and belongs to the same family (Asteraceae), Tussilago is only distantly related to Taraxacum. Coltsfoot is really a type of groundsel (tribe Senecioneae) whereas dandelions are related to chicory (tribe Cichorieae).
Coltsfoot is unusual in that it produces its flowering stems long before the leaves that give it its common name, the plant’s reproduction powered by the energy that it stored up the previous year. Dandelions, like most herbaceous plants, produce their leaves first, then flower. That’s not the only difference to dandelions though.
The Database of Pollinator Interactions (DoPI) lists 9 species of insect that have been recorded as visiting coltsfoot for nectar and/or pollen. In contrast, the entry for Taraxacum officinale lists more than130 species as flower visitors. I thought initially that it might be due simply to under-recording, but this study of coltsfoot in Germany only recorded 16 insect species. So the greater attractiveness of dandelion is likely to be real. Why the big difference in pollinators?
One reason for it could be that dandelions have a very different flowering strategy; they can be in flower 12 months of the year, depending on local weather conditions, with a reproductive peak in May or June. They therefore have the opportunity to interact with many more insects than coltsfoot, which in contrast you generally only see in flower between March and May at the very latest.
Dandelions are also much more abundant than coltsfoot which is no doubt also a big factor in determining how often insects are observed on the flower heads. It’s not unusual to see whole fields full of dandelions in flower but I’ve never seen coltsfoot do that, perhaps because they prefer to grow on rather disturbed ground.
There may be some other factors at play here that I’m not aware of, for example a lower rate of nectar production in coltsfoot. Having said that, the fact that dandelions produce any nectar at all is a real conundrum. All of the literature claims that Taraxacum officinale is “apomictic“, a plant reproductive strategy in which seeds are produced without requiring ovules to be fertilised by pollen. In fact the online Ecological Flora of Britain and Ireland entry for dandelions lists the pollen vector as “none” for that very reason. But I’m sure that the real story is more complicated, otherwise why would these plants invest so much of their energy and resources in attracting and rewarding flower visitors? I’ve not delved deeply into the Taraxacum literature so perhaps one of my readers knows?
Our encounter with coltsfoot reminded me of the work that I did last year with the Stanwick Lakes nature reserve in Northamptonshire, advising on how best to enhance and manage the site (which is primarily a bird reserve) for pollinators. One of my recommendations was that they enlist their volunteers to collect seeds and root or stem cuttings from the small, isolated populations of early-flowering plants such as coltsfoot (pictured on the reserve below) and introduce them around the site in suitable spots. This would both increase the availability of nectar and pollen for the first flower visitors of spring, and also the ecological connectivity between different parts of the site as the pollinators are able to move around more effectively. So I was delighted to see this post on LinkedIn from Liz Williams who works at Stanwick, demonstrating that they have taken my advice on board and begun the hard work of planting for pollinators.
My work with Stanwick was an example of the advisory and consulting services that I offer. If you’d like some advice on how to improve an area for pollinators, or for biodiversity more broadly, please do get in touch via my Contact page.
In September 2016, along with 11 other pollinator & pollination scientists, I took part in a two-day two-day workshop held at the UNEP-World Conservation Monitoring Centre in Cambridge. The aim was to develop a range of simple, practical methods to enable the valuation of insect pollination services to agricultural crops that are provided by a nature reserves or other natural or semi-natural habitats, for TESSA – the Toolkit for Ecosystem Service Site-Based Assessments.
After a long gestation, caused not least by the COVID-19 pandemic, the paper outlining the methods that we developed has been published. It’s open-access and downloadable for free. Here’s the full reference with a link to the paper:
Pollinator declines have prompted efforts to assess how land-use change affects insect pollinators and pollination services in agricultural landscapes. Yet many tools to measure insect pollination services require substantial landscape-scale data and technical expertise. In expert workshops, 3 straightforward methods (desk-based method, field survey, and empirical manipulation with exclusion experiments) for rapid insect pollination assessment at site scale were developed to provide an adaptable framework that is accessible to non-specialist with limited resources. These methods were designed for TESSA (Toolkit for Ecosystem Service Site-Based Assessment) and allow comparative assessment of pollination services at a site of conservation interest and in its most plausible alternative state (e.g., converted to agricultural land). We applied the methods at a nature reserve in the United Kingdom to estimate the value of insect pollination services provided by the reserve. The economic value of pollination services provided by the reserve ranged from US$6163 to US$11,546/year. The conversion of the reserve to arable land would provide no insect pollination services and a net annual benefit from insect-pollinated crop production of approximately $1542/year (US$24∙ha–1∙year–1). The methods had wide applicability and were readily adapted to different insect-pollinated crops: rape (Brassica napus) and beans (Vicia faba) crops. All methods were rapidly employed under a low budget. The relatively less robust methods that required fewer resources yielded higher estimates of annual insect pollination benefit.
Join me this Thursday at a free online talk organised by Buglife where I’ll be giving an introduction to how flowers function and the ways in which their behaviour manipulates pollinators to ensure reproduction. I’ll be covering:
What are flowers and where did they come from?
How flowers function and reward pollinators.
Some case studies from my own research on flower and pollinator behaviour.
Why is it important that we understand floral biology?
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:
Prof. Jeff Ollerton - ecological scientist and author 