‘…people would need to be very weak in the head… before it would occur to them to go into the garden and eat snails…’
Anon. (1867)
Delighted to announce that my essay “A short history of snail-eating in Britain” will be in October’s issue of British Wildlifemagazine. This is a topic that’s intrigued me for many years because it has a close connection to the snail-eating habits of folks (my own family included) in the area of the north-east of England where I grew up. Hopefully it will also interest, and surprise, the readers of British Wildlife!
Today I returned the final, edited files of the book manuscript to the publisher. It’s been a long summer of ‘fine distinctions and nice judgements’, to quote my editor, the inimitable Hugh Brazier. Now that’s all finalised, I thought that it was time to share the chapter titles with you – here goes:
Introduction: Encounters with birds and flowers
1 Origins of a partnership
Understanding 50 million years of bird and flower evolution
2 Surprising variety
The astounding diversity of pollinating birds
3 Keeping it in the family
Accounts of the different groups of bird pollinators
4 A flower’s point of view
How many plants are bird-pollinated, and where are they found?
5 In the eye of the beholder
What do bird flowers look like?
6 Goods and services
The enticements given to birds for pollinating flowers
7 Misaligned interests
The ongoing conflicts between flowers and birds
8 Senses and sensitivities
How bird brains shape the flowers that they pollinate
9 Codependent connections
Networks of interacting flowers and birds
10 Hitchhikers, drunks and killers
The other actors in the network and how they affect the main players
11 The limits to specialisation
How ‘specialised’ are the relationships between birds and flowers?
12 Islands in the sea, islands in the sky
Isolation, in oceans or in mountains, results in some remarkable interactions
13 The curious case of Europe
Why did we believe that Europe had no bird-pollinated flowers?
14 ‘After the Manner of Bees’
The origins of our understanding of birds as pollinators, and their cultural associations
15 Feathers and fruits
Birds as pollinators of edible wild plants and domesticated crops
16 Urban flowers for urban birds
Bird pollination in cities and gardens
17 Bad birds and feral flowers
The impact of invasive species
18 What escapes the eye
The decline and extinction of bird–flower relationships
19 The restoration of hope
People as conservationists of birds and their flowers
There you have it! I’m incredibly excited that the book is now just about finished (I still have to proof read the typeset text and produce an index) and I look forward to finally having a copy in my hands. Birds & Flowers: An Intimate 50 Million Year Relationship is available for pre-order from Pelagic Publishing, or via online bookshops.
A pollination ecologist was recently working on the reproduction of a tropical plant species and discovered that the flowers were visited by two species of weevils, one large and one small.
The larger weevil was too big to access the nectar from the front, so it chewed its way into the flowers, destroying the petals, and in the process picking up no pollen.
The other weevil species was, however, able to enter the flowers, where it became smeared with pollen, which it then transferred to the stigmas in flowers of other plants.
The pollination ecologist therefore concluded that the true pollinator of this plant was, indeed, the lesser of the two weevils…
Writing in the open access Peer Community Journal, Julien Haran, Gael Kergoat, and Bruno de Medeiros have produced a really fascinating review of weevil pollination called:
Weevils are beetles, members of the superfamily Curculionoidea, which contains an estimated 97,000 species. Many are herbivores, including seed predators – I first encountered them as a researcher during my PhD when I assessed the impact of one species as a seed predator of my study plant Bird’s-foot Trefoil. Surprisingly, however, pollinating relationships have evolved multiple times between weevils and plants. Drawing on published studies and their own unpublished observations, the authors conclude that such “associations have been described or indicated in no less than 600 instances.” Most of these are brood-site pollination systems that have probably evolved from seed predation relationships.
No doubt many more examples of weevil pollination remain to be discovered but as it stands, this review paper is a great summary of a fascinating and still rather neglected corner of pollination ecology.
There’s an estimated 350,000 described species of pollinators, and many, many more undescribed. Only about 20,000 of these (i.e. less than 6%) are bee species, although you wouldn’t know it from the media obsession with bees. It’s important and and timely, therefore, that a team of South American scientists have come together to propose a special issue of the Journal of Applied Entomology that focuses on these “other” insects.
The special issue will be called “The Neglected Pollinators: Understanding the Importance of Lesser-Known Insect Taxa in Pollination”. Consider submitting a manuscript if you work on anything except bees! Here’s the link to the details of how to submit your work:
The summer of 2019, before the COVID-19 pandemic turned the world on its head, feels like a very long time ago. Early in that summer, as I recounted on this blog, Zoe Xirocostas joined my research group for a while in order to collect data for her PhD on the comparative ecologies of plants that are native to Europe but invasive in Australia. That work has proven to be very successful, and the latest paper from Zoe’s PhD has just been published.
The paper focuses on the “enemy release hypothesis” (ERH), a well-studied concept in invasion ecology that nonetheless generates significant debate and disagreement. In essence, the ERH posits that the reason why so many species become invasive is that they leave their consumers, pathogens and parasites behind when they move to a new locality. Those “enemies” would normally reduce the fecundity of the invader, putting a brake on their population growth. But in their absence, the invader can become far more successful. Of course, as well as leaving “enemies” behind the invader also loses its “friends”, such as pollinators, seed dispersers, and defensive or nutritional partners. This “Missed Mutualist Hypothesis” is something that I’ve recently explored with Angela Moles, who was Zoe’s main supervisor, and other collaborators in Australia. Expect to hear more about this from Zoe’s work in the near future.
But back to the enemies. Drawing on the most extensive set of standardised comparisons yet collected of the same plants in native and invasive habitats, Zoe found that plants in the invasive populations suffer on average seven times less damage from insect herbivores, as predicted by the (ERH). Rather remarkably, however, the amount of enemy release enjoyed by a plant species was not explained by how long the species had been present in the new range, the extent of that range, or factors such as the temperature, precipitation, humidity and elevation experienced by the native versus invasive populations.
In other words, it’s extremely hard to predict the extent of enemy release based on historical and ecological considerations that one might expect to impose a strong influence.
The study has just appeared in Proceedings of the Royal Society series B and is open access. Here’s the reference with a link to the paper:
When a plant is introduced to a new ecosystem it may escape from some of its coevolved herbivores. Reduced herbivore damage, and the ability of introduced plants to allocate resources from defence to growth and reproduction can increase the success of introduced species. This mechanism is known as enemy release and is known to occur in some species and situations, but not in others. Understanding the conditions under which enemy release is most likely to occur is important, as this will help us to identify which species and habitats may be most at risk of invasion. We compared in situ measurements of herbivory on 16 plant species at 12 locations within their native European and introduced Australian ranges to quantify their level of enemy release and understand the relationship between enemy release and time, space and climate. Overall, plants experienced approximately seven times more herbivore damage in their native range than in their introduced range. We found no evidence that enemy release was related to time since introduction, introduced range size, temperature, precipitation, humidity or elevation. From here, we can explore whether traits, such as leaf defences or phylogenetic relatedness to neighbouring plants, are stronger indicators of enemy release across species.
Late on Wednesday night, Karin and I returned, tired but happy, from an eight-day trip to southern Spain, where we celebrated the marriage of our son Oli to his partner Kate. Our base for the trip was the small town of Benahavis, a former Moorish enclave in the mountains above the Costa del Sol.
As well as spending time with Oli and Kate and the other guests, Karin and I took the opportunity to explore some of the many trails that meander through this wonderful landscape. One of these crosses, then follows, the spectacular canyon of the Guadalmina river, the trail shaded by over-arching trees that provided relief from the hot sun.
Many of these small trees, I was delighted to see, were oleanders (Nerium oleander) growing in what is (arguably) their natural habitat. It’s been so widely planted for thousands of years that the true origin of this species is unclear, but it’s almost certainly native to the Mediterranean basin.
Twining through one of these oleanders was a plant with heart-shaped leaves and dangling fruit that I instantly recognised – the Andalusian pipe vine (Aristolochiabaetica). As a climber, this plant needs the support of trees and shrubs to enable it to reach the light. The supporting species is not harmed and likely benefits from the nutrients in the dead leaves and flowers that fall beneath it.
The juxtaposition of these two species was so perfectly symbolic of our reason for being in Spain that I had to take the photo that you see above. Why, you may ask? Well the oleander is a member of my all-time favourite plant family, Apocynaceae, that I’ve worked on for more than 30 years. The pipe vine belongs to the Aristolochiaceae, another fascinating family that’s also in my top five favourites.
That’s the thing with families, sometimes they come together and entwine in ways that just feel and look…right. Huge congratulations to Oli and Kate, and our very best wishes for a long and happy future together!
One of the projects in which I’m currently involved is the WorldFAIR project. Funded by the European Commission, WorldFAIR is exploring how to make data FAIR – Findable, Accessible, Interoperable and Reusable – across a range of different disciplines in the sciences and humanities.
My involvement is specifically with Work Package 10, which is focused on data standards for plant-pollinator interactions, particularly as they relate to pollination of agricultural crops. After a year of hard work, I’m delighted to announce that our interim draft report from this Work Package has just been published! You can read the summary and download the report from Zenodo – here’s the link: https://zenodo.org/record/8176978
There’s more to come over the next twelve months and I’ll post updates as and when they appear. In the meantime, do check out the WorldFAIR website for information about the other Work Packages, their webinar series, FAIR data standards, and so forth.
Regular readers of the blog will know that I’m a keen gardener as well as having a deep interest in the natural world, and I know from personal experience how being amongst plants, flowers, birds and insects can lift a person’s mood and improve their health.
It was interesting, therefore, to get a message via my Contact page from a tutor on the Students For Research programme. They had been looking at my blog and the tutor had challenged her students to find a web resource that they thought might interest me. And indeed they succeeded! They found this web page about Clinical Trials on the Positive Effects of Gardening and Experiencing Nature and it makes for very interesting reading. There’s a lot of good research happening in this area.
Earlier this week, the East Midlands Environment Agency proudly tweeted that they had placed honey bee hives on an ecologically important site that they own. As you might imagine, the response from pollinator experts such as myself, conservation NGOs, and some beekeepers, was not positive, as you can see if you look at the comments beneath my tweet:
If this is an important site for nature conservation, as claimed, then the #EnvironmentAgency should NOT put hives of honey #bees on it!
— Prof. Jeff Ollerton – @JeffOllerton@ecoevo.social (@JeffOllerton) July 12, 2023
By coincidence, overnight I received a message from someone in the USA asking for advice. Here’s a redacted version of their message:
My community has a 4 acre serpentine barren site that is part of a larger string of these unique barrens ….. Honey bee hives have recently been located adjacent to the barrens. Can you advise me as to the best way to determine whether there are, and to document any, adverse effects to the serpentine barrens native pollinators?
Going back to the question of how to assess any impacts, the simple answer is that it’s not easy and it relies on having good data. This was my response to my American correspondent:
Ideally you would need to take a before-and-after approach where you have data on things like number of native pollinator species, their abundance (including nest sites), rates of visitation of different pollinators to flowers, and fruit or seed set from particular plants. You’d then compare what was going on before the hives arrived with what’s occurring since their arrival.
If you don’t have the “before” data it’s much more difficult to assess if there has been an impact from the honey bees. However, the advice of most conservation groups is to adopt the “precautionary principle” and not site hives on or adjacent to areas of nature conservation value, especially if they are relatively small areas. See for example the Bumblebee Conservation Trust’s advice: https://www.bumblebeeconservation.org/managed-honeybees/
The precautionary principle is a well established concept across a range of areas, including health and engineering, as well as nature conservation. In the latter it needs to be more widely applied, especially when it comes to questions of where to site honey bee hives, and how many.
Last year I posted about the work that I’ve been doing on railways and biodiversity with UIC – the International Union of Railways – and the UK Centre for Ecology & Hydrology. That work is now complete and the second of our two reports called UIC Guidelines on Managing Railway Assets for Biodiversity is now out.
UKCEH has produced a press release and I’m copying it verbatim below:
New guidelines for the management of Europe’s railway network to protect and enhance biodiversity have been published.
The UK Centre for Ecology & Hydrology (UKCEH) has worked with the International Union of Railways (UIC), the professional association representing rail companies across the world, to provide technical recommendations and key design features for incorporating and enhancing habitats within the existing European network and new line upgrades, providing examples of best practice.
The UIC European region comprises 118-member companies from 39 countries, amounting to 350,000 kilometres of rail network.
Professor Richard Pywell, Head of Biodiversity at UKCEH who is one of the lead authors of the report, said: “We worked closely with railway companies across Europe to distil the best available knowledge on managing railway assets to benefit nature. For each asset, we considered the most effective measures to protect and restore biodiversity, and how to monitor the outcomes of these interventions.”
Another report author, independent consultant Professor Jeff Ollerton, added: “Working with UIC on this project has revealed just how important the land managed by Europe’s railway companies is for nature. The next step is to better understand how nature supports Europe’s economy, and the health and wellbeing of its people.”
The authors used the widely-adopted mitigation hierarchy approach which guides, developers on protecting existing habitats and ecosystems where possible.
The new UIC Guidelines for Managing Railway Assets for Biodiversity have been drawn up as part of the REVERSE project, in which UIC has worked with its members and UKCEH to formulate a collective vision for protecting and enhancing biodiversity across the European rail network. They now form part of the European Railways: Strategy and Action Guide to ensure management for biodiversity is embedded at every level of the railway business, alongside safety, performance and sustainability. The adoption of the guidelines by member companies will be promoted through various UIC meetings and online events.
The REVERSE project comprises more than 20 European rail companies including Network Rail and SNCF as well as WWF (Worldwide Fund for Nature).
In 2021, UKCEH worked with Network Rail to draw up the rail company’s Biodiversity Action Plan to inform lineside habitat management across the UK. This involved using high-resolution imagery from satellites and aircraft to produce a detailed national map of all the habitats alongside the rail network.
Prof. Jeff Ollerton - ecological scientist and author 