Author Archives: jeffollerton

A milkweed on the shore: tracking down an elusive Danish plant

Since arriving in Odsherred towards the end of August I’ve been looking out for one plant in particular on our bicycle rides and hikes around the region. Vincetoxicum hirundinaria is a widespread asclepiad or milkweed: a member of the family Apocynaceae, subfamily Asclepiadoideae. This is a group of plants on which I’ve published quite a few research papers and which feature heavily in my book Pollinators & Pollination: Nature and Society.

So far the species has proven elusive and a few Danish ecologists that I’d spoken with told me they had never seen it in the wild. The GBIF account of the species shows a few populations in this part of Denmark but I wasn’t sure if they were old records of populations that no longer exist. But as of yesterday I can confirm that at least one of those populations is extant!

We had cycled out to the small town of Klint about 13km west of us, to see the glacial moraine landscape for which the area is famous and which gives Odsherred UNESCO Geopark status. As we approached the small fishing harbour at Klint I let out an excited shout to Karin who was just ahead of me: in amongst the roadside vegetation I’d spotted the distinctive and immediately recognisable yellow of Vincetoxicum hirundinaria in its autumnal hues! In the photos that follow you can see how well that yellow stands out against the colours of the other plants in the community.

At this time of the year the plant has ceased flowering, but the occasional swollen green seed pod was evidence of successful pollination of their morphologically complex flowers.

I was surprised at just how close to the sea the plants were growing; they must get inundated by sea water during stormy tidal surges.

So what is pollinating these flowers on this exposed shoreline? That’s a question that I want to pursue in the coming years. The Pollinators of Apocynaceae Database has remarkably few records of pollinators in this species, given how widespread it is. Flies certainly pollinate it, but there’s also records of wasps and bees as visitors, including bumblebees on flowers of a plant that I had in cultivation in Northampton. There’s a couple of other research groups in Scandinavia and Europe who are looking at the pollination ecology of the species and I’m hoping that we can collaborate on a study of spatial variation in its reproduction. Vincetoxicum is quite a large genus (around 150 species) and only around 10% of the species have been studied in any detail. But these studies are revealing a complex diversity of pollinators, including most recently, cockroaches in the Chinese species Vincetoxicum hainanense. I’m sure this intriguing group of plants has more fascinating stories to tell us about the ecology and evolution of its pollination systems.

FIGURE 4 from Xiong et al. (2020) Specialized cockroach pollination in the rare and
endangered plant Vincetoxicum hainanense in China. American Journal of Botany 107:
1355–1365.

If you read only two books this year make them The New Climate War and Silent Earth

My summer reading this year has included two books that I’ve really looked forward to, and which have not disappointed. These books are on the one hand very different and yet share enough similarities for me to review them together. Michael E. Mann’s The New Climate War focuses on the ‘climate emergency’ whilst Dave Goulson’s Silent Earth is about the ‘ecological emergency’, and specifically the decline of insect populations. As I pointed out in a recent New Scientist opinion piece: “the climate emergency often overshadows the ecological emergency, even though the two overlap both in their causes and their solutions”. Reading these two volumes in parallel has given me a much deeper understanding of just how true that statement is, and it’s why I’m suggesting that of the many, many books that have been recently written about our current environmental crisis, these deserve to be the ones that you read.

Silent Earth deals with the billions of small things – the insects and other invertebrates – that make the world function the way it does. These creatures facilitate the recycling of organic material, the pollination of wild and crop plants, the regulation of populations of other species, and play a host of additional ecological roles. The central thesis of the book is that the growing evidence of declines and extinctions of these small animals should give us cause for concern. In contrast, The New Climate War is about the big stuff – how the world’s atmosphere and oceans are heating up, the contribution of human activities to that warming, and what this means for weather patterns and sea levels across the globe. And how industry and politicians have conspired to deny, obfuscate, and divide, undermining efforts to decarbonise the world’s economy.

It matters not whether we view the world through a microscope or via an Earth observation satellite, both of these ways of seeing and understanding are important to our future as a species. The flap of a butterfly’s wings may only rarely be the indirect cause of a hurricane in the Caribbean, but reading these books nonetheless reminds us of the connections between the world’s biosphere and its physical domains.

The science underlying both books acts as a background to their main purpose: convincing the reader that there are urgent issues with which we, as a society, must deal. In this respect they are unapologetically political, and the point at which science meets environmentalism. The books are written by scientists who are respected experts in their respective fields, but who are not content with sitting back on their award- and citation-laden laurels, and allowing their science to speak for itself (as important as that is). Both Mann and Goulson have entered the more public arenas of politics and social commentary to argue the case for fundamental restructuring of some aspects of our societies. Their reward has been near constant criticism, much of it personal, vindictive and even threatening, by the vested interests of the fossil fuel industry (Mann) and agro-chemical & farming interests (Goulson) and the keyboard warriors who labour on their behalf, wittingly or not. That Mann and Goulson persist in voicing their concerns in this way, at the same time continuing to publish high quality science, says much about them as people and their commitment to these important causes.

The stereotype of the cold, calculating, emotionless scientist is shattered by these authors as they frequently refer to their families, especially their children, as a prime motivation for their activism. In an emotive chapter, Goulson imagines his son as an old man sitting up through the night to defend the vegetables that he’s growing with his family in a Britain that has experienced not an apocalyptic collapse of society and basic infrastructure, but “a slow unravelling over decades”. As he remembers back to the world of his youth he wonders: “Why did we fail to act? We humans do not seem to be very good at grasping the big picture”.

The Big Picture is certainly an underlying theme of both books, despite the different scales at which these scientists work, and both are revelatory in their descriptions of what’s occurring behind the scenes. Pull aside the curtain and we see the financial connections between various anti-environmental think tanks and lobby groups (Mann) and the hypocrisy of large business corporations which continue to manufacture highly toxic pesticides that, although banned in the west, can be profitably exported to developing countries (Goulson). All of these messages of corruption and environmental degradation could make the books pessimistic reads. But in fact both have an optimistic undertone, a sense that we know what the issues are, we know what’s got us into this mess, and there are routes out of it. But only if (and it is a huge if) there is the willingness of governments and large corporations to act.

Both writers share a belief in humour and personal anecdotes as vehicles for emphasising important points. For example Mann describing the fearsome and brutal attention given by climate deniers to Greta Thunberg and other youthful activists as being like the Eye of Sauron (one of several Lord of the Rings analogies). Or Goulson’s description of giving a phone interview to Australian radio while lurking in the piss-smelling toilet of a British pub. These books are brought to life by the authors’ experiences as scientists and as advocates, and their passionate wish for a better future.

Full disclosure: this can hardly be considered an objective review as both Dave Goulson and Mike Mann are friends of mine. Dave I met over thirty years ago when we were graduate students in the same department, and we’ve published a few things together. Mike I encountered much more recently, as I described in this post, when we were concurrently on sabbatical at the University of New South Wales and discovered that we were living in adjacent apartment blocks. In some respects the world of science is a very small one. Despite these personal connections I don’t think that I would have said much that’s different about either book had I not known their writers. But who knows, that’s not the way things are. There are certainly things to criticise in both books, and I don’t agree with all of the writers’ conclusions and could debate several points of interpretation with them, especially in Silent Earth where I’m in more comfortable territory. But those would be minor criticisms in light of the conclusions that these important books draw: that our world is changing rapidly, that we are responsible, and that we have a duty to act immediately. It’s not too late, but we need to listen to the science and what scientists such as Mann and Goulson are telling us.

Pollinators and COP26: new article out soon

Watch out for my article in Bees and Other Pollinators Quarterly Magazine about what the forthcoming COP26 climate change meeting has in store for pollinators, including why commitments to developing countries are important and the Grasslands+ initiative.

The magazine is in the shops on October 12th or you can subscribe by following this link: https://bq-mag.store/

Birding in Denmark: my first visit to the Hov Vig Reserve

As well as working on a variety of writing and research projects, Karin and I have spent the last few weeks getting out and about in the Odsherred region of Denmark, exploring the culture and ecology of our new home. Not far from where we are living is the Hov Vig bird reserve which I’d put off visiting until last weekend when my friend and colleague Bo Dalsgaard was due to come and stay with us. Bo is primarily an ornithologist (we’ve collaborated on quite a few hummingbird-flower network studies), so it was going to be a good opportunity to get to know more about the birds of this part of the world.

After an early breakfast we set out for Hog Vig and I have to say that I was extremely impressed by the reserve. As you can see from the map below it’s been created by installing a low causeway across a bay in the fjord, resulting in a shallow, brackish lagoon that is absolutely teeming with bird life! Shallow lagoons like this are very productive, with lots of invertebrates and plants on which the birds can feed.

You can see the start of the causeway on the middle left of this photo:

I hadn’t realised just how shallow the lagoon was until I spotted a Great White Egret wading across the centre, the water barely reaching the middle of its legs. In all we counted 8 of these egrets, though a local birder we encountered told us he’d seen 14 that day. Interestingly, Little Egrets are considered quite uncommon here, a reverse of the situation in the UK.

Although the total area of the reserve, including woodland, is only 334 ha, an extraordinary 267 species of birds have been recorded there:

On the reserve itself we identified 39 species, and a handful more when we visited the nearby coast. Including those that we were unsure of we had just over 50 species, not bad for a day of birding. As well as the egrets, particular highlights were huge numbers of Teal, on the water, large active flocks of Golden Plovers and Lapwings set into motion by a hunting Sparrowhawk, and Bar-tailed Godwits, Stonechats and Eiders.

The most exciting birds for us, however, was a pair of White-tailed Sea Eagles that descended onto one of the low islands in the lagoon to feed on a dead cormorant! The locals describe these birds as ‘flying doors’, very apt given their huge wingspans. Needless to say, their appearance also sent much of the bird life into the air. Here’s a poor photo taken with my camera through Bo’s telescope:

And here are two very happy birders!

A Copenhagen (and beyond) Bestiary – part 5

At the end of August I was back in Copenhagen for a couple of days to take part in the PhD defence of Céline Moreaux, who has been working on coffee pollination and bee conservation. While I was there I snapped a couple more images for my Copenhagen Bestiary series. However I’ve also seen some interesting sculpture and building decoration further afield this month, in Aarhus, Silkeborg, and Nykøbing Sjælland. I especially like the wooden carved canopy support in the form of a duck, from Aarhus: it’s very subtle and I almost walked past it.

And before anyone asks, no, Karin and I are NOT part of the bestiary, but I didn’t get a shot of the troll by itself.

Diversity and surplus: foraging for wild myrobalan plums

Cycling back from town this afternoon, Karin and I passed a hedgerow that was bursting with wild myrobalan or (cherry) plums (Prunus cerasifera). We had to stop and collect some, and soon filled a bag. What’s always intrigued me about these small, tart little plums is just how diverse they are: the image above shows the plums from six different trees. All of these are, in theory, the same species; but clearly there’s a lot of genetic diversity. In colour, the ripe fruits range from golden yellow through to dark purple, and vary in the amount of dark-contrasting streaking, lighter speckling, and waxy bloom. They are also variable in size, shape and taste.

All of this variation probably reflects the long history of cultivation of this European archaeophyte. The species is originally native to southeast Europe and western Asia, and was likely spread throughout Europe by the Romans. The local deer population is very fond of the fruit and we’re seeing a lot of deer droppings that are packed with seeds. We don’t usually think of these large mammals as seed dispersers, but I suspect that they are very successful in that ecological role.

As well as being a great source of wild fruit, for humans and wildlife alike, at the other end of the year these trees are important for pollinating insects. As I pointed out in my book Pollinators & Pollination: Nature and Society, Prunus cerasifera is one of the earliest flowering woody plants in northern Europe, and its flowers are an important nectar and pollen source for early emerging bumblebee queens, hoverflies, and honey bees.

Delicious, abundant fruit combined with a valuable role for pollinators: what’s not to like?

Wild mushrooms, tragic deaths, and the importance of understanding nature

A sad and timely news story caught our eye this morning: the death of two young Afghan boys in Poland who were poisoned after their family collected wild mushrooms to make a soup. Other members of the family were hospitalised. As Karin read out the story to me, I was moved by the tragedy of these events for a family fleeing a war zone, but also angered by pointlessness of the loss of those brothers’ lives, just more death-by-wild-mushroom statistics. In Europe we read about such events every year in the autumn, the peak of wild fungus foraging. And quite often the deaths are of people who have recently moved to an area and mistake poisonous mushrooms for edible ones from their country of origin.

At their root, these tragic stories of lost lives and broken families are stories of misunderstandings about nature. In particular, they are about not appreciating that plants, mushrooms, animals, and other wildlife, are not the same all over the world. There are biogeographic differences between regions that reflect the long-term history of life on our planet. Plants or mushrooms that look superficially similar in different parts of the world may have very different evolutionary histories. Histories that can make the difference between good to eat and deadly poisonous, between life and death.

The mushroom which killed the boys was a Death Cap (Amanita phalloides) which is found across Europe and the Mediterranean basin. As far as I can tell from its GBIF records, it does not occur in Afghanistan. The family presumably mistook this mushroom for one with which they were familiar, perhaps a different species of Amanita, which contains both deadly types and some that are good to eat. This terrible and fatal mix up could so easily have been avoided.

I’m not certain if resettlement agencies provide information about the foraging of wild food, or if basic facts about local nature are provided to those new to these areas. This is a simple action that could save lives and further tragedies for families trying to recover after the disruption of moving to a new country. It may be that this family was trying to carry on traditions of foraging in an effort to feel at home.

Since we arrived in the Odsherred region of Denmark, where Karin and I intend to settle, we have been exploring the woods and beaches on our newly bought bicycles. Much of the natural history is familiar to me from Britain, but there’s also some interesting differences and in future blog posts I’ll discuss this further. Last week we happened across a Lithuanian woman and her mother who had been foraging for mushrooms in the forest around their summer house. They were pushing a baby’s pram, the lower basket of which was stuffed with fungi. Picking and eating wild mushrooms has been something I’ve enjoyed since I was a teenager, so I had to stop and chat with them. They showed us some of their finds, including species with which I wasn’t familiar and that I will research further.

Lithuania and Denmark are of course quite close to each other geographically. Nonetheless the younger woman was still discovering which of the local mushrooms were good to eat: ‘I learn one new edible species each year’ she told us ‘That’s a good rule, then you don’t get confused’.

Since that meeting we’ve had several meals from mushrooms collected in the area, including some very fine ceps (Boletus edulus). I will keep in mind the woman’s words and proceed cautiously when it comes to discovering what is edible and what is not.

To end this rather sad but hopefully thought provoking post, Karin and I send our deepest condolences to the Afghan family and our heartfelt wishes that they can recover from these tragedies that must have deeply affected their lives.

Claims that only 10% – and not 75% – of crops are pollinator dependent are misleading and dishonest

Earlier this week the Genetic Literacy Project site posted an essay entitled ‘10% — not 75% — of crops pollinator-dependent: Our World in Data debunks claims that global food supply is imminently endangered by ‘disappearing’ insects‘. That click-bait title is hugely misleading, some of the purported ‘facts’ are incorrect, and indeed the whole thing reeks of dishonesty and bad faith.

First the misleading title. This ‘debunks’ claim actually compares two different things: 75% of CROPS being dependent on pollinators versus 10% of crop YIELD. However, even if we focus on the 10% claim, a small increase in yield can be the difference between profit and bankruptcy for small-scale farmers. And most of the world’s farmers are small-scale and living on the borderline between loss and break-even. In addition, there’s no acknowledgement of the food production from home gardens, allotments, and community gardens, which is significant but largely unquantified.

Next, by focusing on yield and comparing, say, wind-pollinated wheat with insect-pollinated apples, the article takes no account of the fact that many of these crops that depend to some extent on pollinators mainly provide essential vitamins and minerals – not calories – to diets. When I tweeted about this earlier in the week, one person commented that they describe the insect-pollinated foods as ‘an important source of flavour and colour in our diets, rice and wheat are all well and good, but you do kinda need something more than grey slop to live’. Another said: ‘I’m so glad you mentioned this. I’m sick of reading articles that praise innovations to increase calories, when what we need is better nutrition from vitamins, minerals & fibres’.

Both great points, and well made.

That essay was also factually incorrect when it described roots crops such as carrots or some of the leafy cabbages and lettuces as not requiring pollinators. Many varieties of these crops ARE pollinator dependent: how do they think we get the seed for the next year’s crop?! And there are many crops and varieties that have not been evaluated for their dependency on pollinators: the 75% figure actually refers to the 115 most productive crop plants (Klein et al. 2007).

When I tweeted about the essay I commented that I was very disappointed by ‘Our World in Data’ – they are usually better than this when it comes to the facts. What I hadn’t appreciated at the time was that in fact the Genetic Literacy Project had highjacked the original piece by Hannah Ritchie and reworked it to give it a very different slant*.

This is where it starts to get dishonest and in fact the Genetic Literacy Project (GLP) has form in this area. The Sourcewatch site describes the GLP as ‘a corporate front group that was formerly funded by Monsanto’ with a remit to ‘shame scientists and highlight information helpful to Monsanto and other chemical producers’. In other words it’s heavily tied to Big Agriculture which, of course, would like us to believe that there’s not an issue with declining pollinators, that pesticides and agricultural intensification are our friends, and that Everything Is OK. Read the full account here.

Frankly, the GLP is so tainted that I’d not believe anything that they publish.

Pollinator decline and the role of pollinators in agriculture are complex issues. If you’d like to know more about the importance of pollinators to agriculture, complete with some accurate and objective facts, then there’s a whole chapter devoted to the topic in my book Pollinators & Pollination: Nature and Society.

*Note that I’ve been communicating with Hannah about the root and leaf crop issue and she accepts that this needs to change in the original. She’s also asked the Genetic Literacy Project to take down their version as it contravenes copyright.

Reference

Klein, A.-M., Vaissière, B.E., Cane, J.H. et al. (2007) Importance of pollinators in
changing landscapes for world crops. Proceedings of the Royal Society of London B
274: 303–313.

What to do if you have beewolves nesting in your garden? Leave them alone!

Earlier today we had a message from the owner of the AirBnB that we are staying in to let us know that he’s expecting a guy to come and spray pesticide around the house to kill the ‘invasive’ beewolves. The European beewolf (Philanthus triangulum) is a type of wasp in the family Crabronidae that is only distantly related to the typical wasps that you find trying to share your barbecue and beer. As its name suggests, it preys upon bees, but it’s actually a pollinator itself and visits a range of flowers.

I immediately got back to our host and pointed out that beewolves are gentle insects, completely harmless, and less dangerous than the pesticide the company would use to kill them, and that he was wasting his money. He informed us that the pest control company had told him that he needed to control them other wise he’d be ‘over-run’ with them next year!

When I explained to him that this was nonsense, and that the beewolves cause no damage to people or property, he promised to get back to the company to cancel the order, and thanked me for the information. I’m hoping that I’ve made a convert to the cause of insect conservation!

It maddens me that pest control companies are preying on people’s fear of insects to make money in this way. Insects are subjected to enough assaults by human activities without making up spurious reasons for poisoning them.

So if you are lucky enough to have beewolves in your garden, please treat them with respect and watch their fascinating behaviour:

A Copenhagen Bestiary – part 4

We have now left Copenhagen, taking a (very comfortable) train over to Silkeborg to catch up with Karin‘s family for a week. So this is the final installment of the Copenhagen Bestiary for now, but I’m sure that I will add to it as I return to the city and explore further. I suspect that there are many more creatures to discover adorning the architecture of that wonderful city. And then there’s Aarhus, Odense, Roskilde….