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Can Plants Talk?

Closeup to Sensitive Plant Flower, Mimosa Pudica

Do you believe plants can communicate with each other? Or even with us? Can they learn, and pass on their knowledge?

This is the subject of a fascinating and startling book by Monica Gagliano, Thus Spoke the Plant.

Monica, Research Associate Professor of Evolutionary Ecology at The University of Sydney, initially discovered plants could listen and react to sounds in their environment. She found pea seedlings responded to the sound of water, a pretty useful biological response when you’re a plant.

She then devised several intriguing experiments where not only did plants appear to learn, but they seemed to remember what they’d learned. She used lots of little plant pots containing Mimosa pudica, otherwise called the sensitive plant, known for its reaction of rapidly folding away its leaves when disturbed.

In one experiment, Monica repeatedly dropped the little plants, in their pots, a small distance. Over time, the plants no longer folded away their leaves in response to being dropped. To test whether they had learned from their experience or were simply worn out, she challenged those plants which had stopped responding by exposing them to a novel stimulus: vibration. Hey presto they reacted to this new perceived threat, so they weren’t exhausted after all. But then she dropped them again, and again they didn’t respond. It did appear the plants had learned to ignore the stimulus of dropping – they had remembered that the drop was not a threat. What’s more even almost a month later in the absence of any ongoing dropping, they still failed to respond when they were dropped.

This begs the question of how does a plant learn and remember if it has no brain? Indeed, Monica’s groundbreaking study was met with scepticism by the scientific community. This has been commonplace throughout history when science has been confronted by concepts difficult to comprehend. Remember, once the earth was flat…

Because they don’t possess a nervous system as do animals, plants have long been thought of as inanimate and passive. But plant cells and tissues do communicate, using proteins, hormones, minerals and so on. A plant needs to be able to do this to live, and to react to positive and negative aspects of its environment like sunlight or the presence of predators, both for its own benefit and that of other plants. As any gardener knows, seedlings are determined to grow towards the light. Meanwhile, studies have shown plants emit airborne substances when munched by insects, serving to warn other plants in the area about this threat, and stimulating their neighbours to beef up their natural defences against the predator.

One area of plant communication about which we currently know very little is their ability to communicate via the bacterial and fungal community living in the soil around their roots. Research has discovered plants are capable of modifying the species of bacteria surrounding them for their own benefit. They do this by releasing substances through their roots which feed the types of bacteria and fungi they want to be there.

It’s even been suggested the composition of the microbial community in the soil around a plant’s roots can encode information and so preserve ‘memories’ in the soil, as well as help the plant perceive things well outside its own reach.

If plants can communicate and learn, does this mean they are sentient beings? This is the subject of much debate, but one thing is certain – we still have a lot to discover about the plants we often take for granted.

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Nature

A Year in the Life of a Stork Watcher

Prehistoric wings beat slowly, deliberately. The bird circles the tree, once, twice, three times before finally landing in slow motion. First, long legs drop onto the bowl-shaped pile of sticks, soon followed by a flurry of white and black feathers, a swan-like white neck and a carrot coloured beak. The haphazard nest, as if thrown together as an afterthought, judders but holds fast as the bird slowly folds its wings away.

These birds are the reason I’m sitting on a makeshift camping stool in the middle of a scrubby former field, surrounded by brambles, notebook in hand, my forehead damp from the mizzly rain. As a volunteer stork watcher for the UK White Stork Project, I’ve been watching these birds for a year now and I’ve been with them through sunshine, gales, rain and hail.

The female bird crouched in the nest throws back her head in greeting and two bills clack clack clack in unison. The sound stirs something deep inside me. The male bird balances on the nest like a tightrope walker as the female hauls herself to her feet, stares at her eggs for a long moment, and launches herself into the air. Her legs trail behind as she flaps, flaps, flaps slowly away, black wingtip feathers reaching out like fingers. At the nest, her mate fussily rearranges their home, picking out scraps of nesting material in the tip of his beak and flinging it aside.

The UK White Stork Project was founded in 2016 with the aim of reintroducing this lost species to the UK. The project’s ambitious goal is to establish 50 breeding pairs in the south of England by 2030 in a release programme phased over five years. The vast rewilded estate at Knepp, West Sussex, a former dairy farm handed back to nature over 20 years ago, was chosen as an ideal location. Not only does it have an astonishingly diverse habitat, supporting a wealth of bird species and a rich banquet of invertebrates – food for the storks – but its location in the south of England means it’s an obvious first stop for any stork flying to the UK from Europe. As a bonus, Knepp’s wildness means storks can do their thing in peace.

Humans and storks rubbed shoulders in Britain for thousands of years, archaeological evidence suggesting they nested here – often choosing nesting sites close to people – as long as 360,000 years ago. Sussex seems to have had a particular connection with these birds, revealed by place names such as Storrington, meaning Village of the Storks. Their rattling greeting would have been part of the background of life for our ancestors. Now long gone, but still buried deep in our consciousness is that sound. Hear it and I guarantee the hairs on the back of your neck will stand to attention.

No one knows exactly why storks disappeared from these shores. They were a delicious addition to the cooking pot in England of old, a tasty treat for the social elite, but their fate may have been sealed by their long links with hope and rebirth, thought to have arisen from Greek mythology. During the English Civil War, this association connected storks with rebellion, and they were persecuted to extinction. Storks hung on in Europe, though, and are a familiar sight, their nests perched atop tall buildings like chimneys or church steeples.  They’re welcome there, too, thought to bring good luck. It’s not uncommon to see cartwheels erected onto the roofs of buildings, providing a platform to encourage storks to build their shaggy nests.

Initially, Project Stork brought wild-fledged disabled storks from Poland to the Knepp estate. These birds, unable to fly after colliding with power cables or falling victim to road traffic accidents, pottered about in a spacious, open-topped pen in the heart of the estate. The idea of forming this initial static population was to act as an avian magnet, drawing in any wandering storks from Europe which happened to be flying over the UK. The White Stork Project’s two satellite sites, in Wadhurst, East Sussex and Wintershall in Surrey make a convenient flyover triangle in South East England, close to the English channel. This approach has been successfully used to restore stork populations in Europe. The strategy worked, as at least two wild birds are thought to be now nesting at Knepp.

The initial population was soon joined by the late summer release of captive-bred birds from the Cotswold Wildlife Park. These wasted no time in taking to the Sussex skies, echoing the past as they rode the thermals like modern pterodactyls.

The UK was in the grip of lockdown in spring 2020 when the first storks to successfully nest in the UK for over 600 years were confirmed to have hatched four precious chicks. Stork watchers and impatient birders were confined to their homes and gardens. But history had been made.

In 2021 the storks were back with a vengeance, this time with seven nests built and 14 chicks fledged. 2022 looks set to be a bumper year. Stork watchers are dividing their time between twelve nests, containing 37 eggs, and counting.

Lofty stork nests aren’t the most accessible structures to keep an eye on, and data on stork behaviour in the UK is in its infancy. The observations of stork watchers as we crouch in the undergrowth are helping to build up a picture of the lifestyle of this often surprising bird. Every bill-clacking greeting, every hunched over, wings-extended pair-bonding display, every feeding foray are meticulously recorded, information that will over time provide detailed knowledge about UK storks.

Stork watchers need to play detective, then. It doesn’t take much to deduce when love is in the air – I’ve watched as pairs get together and mate in early spring, serenaded by stereophonic birdsong. Day by day nests grow as the birds fly back and forth, back and forth adding to the construction, stick by painstaking stick. But only by watching and waiting does it become obvious when the birds hunker down, the first clue that eggs have been laid.

I’ve held my breath along with my fellow stork watchers, anxiously checking the calendar and crossing fingers for no fierce spring storms until the first sighting of parent birds regurgitating food into the nest. This means the young storks have successfully chipped their way out of the eggs. Storks lay between four and five eggs, and the tiny chicks aren’t visible from ground level for a couple of weeks. The rush of adrenaline when the first chick pokes its wobbly head over the rim of the nest makes the hours on the camping chair all worthwhile.

credit: Rob Dumbrell

Storks are tender parents, placing food into the centre of the nest so all chicks have an equal chance of eating. As the chicks grow older, more boisterous, and ever larger, they jostle each other for space as they rapidly outgrow their home. They soon become their parents’ mini-me’s: hardly distinguishable from the adult birds, save for their grey beaks. There are inevitable casualties along the way. We cheer for the ones that do make it, but such is the bond between watcher and stork, it’s hard to be unaffected by the ones that don’t. Eventually, the lucky ones are spotted trying out their stilt legs for size before, around two months after they hatch, taking their first dizzying flight.

Things don’t always go according to plan in the stork world, however. One of the advantages of having many pairs of eyes trained on a single species – 43 volunteer stork-watchers are actively involved in the White Stork Project – is the opportunity to bust some myths. And the Knepp storks wasted no time in deciding they didn’t want to be pigeonholed.

Storks are generally believed to return to the same nest site with the same partner year on year. It makes perfect sense for migratory birds like storks to be monogamous because they simply don’t have the time or the energy to look for a new partner after completing a long migration flight. Faithfulness to nesting sites means energy doesn’t need to be expended building a new nest each year.

In early spring 2022, however, a game of musical nests began. One nest, hidden in a quiet corner of Knepp had deteriorated, as homes do when they’re not used for a while. Spotted repairing this nest was a young dashing male, whose leg ring bore the number GB5F. The previous year’s occupants of the nest returned to find it occupied so they stole an adjacent nest from its previous owners, who in turn were forced to build a new nest elsewhere.

GB5F was soon joined by a female, GB29. She had raised a chick the year before with a different male on a nest perched on the chimney of the Knepp Estate castle building.

It wasn’t long, however, before the stork watchers noticed that GB29 was absent from her new nest as often as she was present. An eagle-eyed observer spotted her on the webcam trained on her original nest on the castle, cosying up with her old partner. She dallied between the two males for several weeks, nest building and mating with them both, sending the stork watchers’ messaging group wild with gossip and speculation. Of course, she was simply ensuring her chicks received the best genes by trying out various males.

GB29 finally settled with her original partner on the castle, leaving GB5F sad and alone on his beautifully-repaired nest. It seemed she preferred her old nest on the castle after all, so the press was alerted to the webcam with great fanfare. But that very day she and her partner started building a new nest in a Scots Pine tree, close to the castle but out of sight of the camera, leaving the much-trumpeted webcam trained on an empty nest. So it seems when push came to shove, GB29 was coy after all.

But what became of GB5F, left high and dry on the nest he’d purloined? Nobody knows, because shortly after his partner deserted him, the plot thickened. Another female was spotted on the nest, mating with an unringed male. It could have been jilted GB5F who’d lost his leg ring, or it could have been a wild bird, but GB5F hasn’t been spotted since.

European storks migrate in late summer, the birds flying thousands of kilometres towards the warmer climate of Africa. Given suitable thermals and a tailwind and they’ll take off en masse, soaring gracefully at first then flapping those gigantic wings. The sight of storks in vast numbers, soaring higher and higher, stays etched in the memory.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       

Usually, young birds take off on their first migration not long after fledging, only returning to their birthplace after two to three years when they’re ready to breed. In 2019, 24 UK captive-bred juveniles were released, some making their way to Europe with one, Marge, flying over 4,000km in just 25 days. The class of 2020 wild-bred juveniles, along with others bred in captivity, also dutifully took off, with sightings soon coming in from as far afield as Morocco.

credit: White Stork Project, Becca Young

In 2021, however, the youngsters decided to buck this trend. On a glorious day in early September, a little later than expected, all eyes were on the sky as the whole gang of juveniles took off, with excited reports of sightings soon pouring in on social media. Storks seem to like mooching about for a while before crossing the channel. The previous year’s cohort ventured as far afield as Cornwall before deciding a shorter channel crossing from Dover would be a more sensible use of their resources. 2021’s youngsters did head to Kent, but to the north coast, away from the English Channel, before hotfooting it to Wadhurst, where they spent the winter.

Several of the juveniles had been fitted with fancy radio transmitters to provide valuable data about their migration routes. Otherwise, the only information comes from sightings of the unique numbers on their leg rings, reliant on birders armed with a powerful pair of binoculars. Far from recording the birds’ movements across France and Spain and onto Morocco or the Sahara, the GPS signals showed them pottering about West Sussex like pensioners on a day out.

This year, things are looking more promising. Several of the juveniles, after exploring Brighton, Cornwall and Kent, have already made the channel crossing into France and on to Spain. Watch this space for more stork updates soon.

Nature

The Wasps are Dead! Long Live the Wasps!

I peer at the perfect, tenderly constructed, hexagonal nest. Yellow and black striped bodies warn me to keep a respectful distance. I’d strayed too close to a nest last autumn, invaded their personal space, and I remember those angry barbs. But these wasps seem calm, going about their business looking after their papery nest. It’s constructed of chewed plant leaves and dead wood mixed with wasp saliva and it’s the most beautiful thing.

But really, under the terrace chair, could you not find somewhere less inconvenient to nest?

I feel a pang of guilt because I know the rough old brick wall facing the terrace, full of nooks and crannies and thousands of inviting holes, had been these wasps’ home in previous years and they hadn’t bothered us at all. But the wall had been rendered, it was now impervious, and the wasps had nowhere else to go. A tiny example of what’s happening every single minute of every day, all over the world, to deprive nature of homes. More of us means less space for them.

Wasps are hated, almost universally. I challenge you to find me a dozen people who love wasps, let alone tolerate them. And let’s face it, they are annoying. All those ruined picnics and barbeques in the lazy late summer sunshine made anxious and frantic with wasp-swatting. Everyone remembers the time when a wasp got tangled in someone’s sister’s hair, or when the boy down the road had to be rushed to hospital because they were allergic.

It’s true wasps are at their most annoying in late summer when they seem to be brimming with confidence and are oh-so-easily angered. But it’s early in the season and these gals are in the business of building a nest, and apart from their legs-dangling, blundering, zig-zag flight, they’re not alarming at all.

Wasps do have a purpose, as has everything in nature – and it’s not simply to annoy us. They’re efficient pollinators, and they love to eat gardeners’ nemeses like caterpillars and aphids, carting them off and feeding them to their offspring. They’re a vital part of the complex ecosystem of nature.

It’s only as those last barbecues of the season are being lit that wasps pester us for sugar. Over the summer their reward for feeding their grubs is a sugary secretion, keeping their energy topped up for the demands of parenthood. But when the grubs evolve into pupae, their parents need a serious sugar fix.

There are tens of thousands of species of wasp, from the ingenious potter wasp creating exquisite, miniature vases for its offspring, without the benefit of a potter’s wheel, to the mud daubing wasp, which spits chewed earth all over our ceilings when we’re not looking. Mason wasps disappear into the many cracks in the building, hiding their babies away. All have fascinating lifecycles, intricate social hierarchies, can control the gender of their offspring, and are diligent parents.

Stop the developers! Stop oil! Prevent ecological collapse! We yell.

Kill the wasps! We cry, as we swat them away from our jam sandwich. Be careful – wasps will sting you as soon as they look at you, we say.

I knew, as soon as our neighbour saw them, that these pollinators were doomed.

It’s OK, they’re only wasps. They have to be killed, they’re so annoying. A menace. Bloody wasps. The justifications come thick and fast.

‘Please don’t kill the wasps’, my voice is thin, reedy, pleading. Nobody listens.

I cry for the dead wasps, and their empty, beautiful nest. I weep for all the creatures dying every day, because of us. All those annoyances and nuisances condemned to death.

As the temperature rises and people speak of brutal heatwaves, we need our wasps more than ever.

Long live the wasp!

Nature

It’s a Gull’s Life

A raucous, competitive clamour pierces my thoughts. On the promenade ahead, teenage gulls play rugby with a bagel, tossing it aloft for their teammates to catch. Each bird’s obsession with winning the delicious prize sees all honourable rules of the game abandoned. Then, to some secret signal, the entire rumbustious team take off and leave their bounty behind.

Many people in my town don’t like gulls. They’re depicted as cheeky, aggressive chip-stealers, refusing to take no for an answer. I prefer to think of them as opportunists. Birds which have crafted a living alongside us, feeding on our smelly castoff food, nesting on our chimneys and boldly walking among us.

Newspapers overflow with seagull nuisance stories, despite there being no such thing as a seagull. Read them and you’ll probably picture a herring gull, the poster child of the gull world. This gull wears its sleek grey body with pride, sporting a handsome flash of black tail feathers and a pure white chest. They’re big bully gulls with a steely gaze and a banana yellow bill, standing tall and stiff on their pink legs. Adolescent herring gulls, like the rugby players, gather in large groups chaperoned by one or two adult birds, boisterous creches of brown and white speckled mischievousness.

I’m delighted by their ingenuity. I love to watch them dropping mussels from a great height onto the shingly beach, the impact cracking open the shells to reveal dinner inside. Crows do this too – I’m not sure who taught who. And then there’s the comical sight of a gull in Riverdance mode, stomping away on a patch of grass. The tap tap tap of feet convinces the worms below it’s a rainy day, and they slither to the surface only to be impaled on a scissor-sharp yellow beak.

Sharing a life with gulls does have its downsides. Gulls rise at first light and are strident alarm clocks. We hop and skip down our street over rubbish scattered by hungry gulls. Where I live, leaky roofs are never fixed during nesting season – approach a rooftop roost and a bombing run will commence. One spring, my neighbour took to scuttling down to her garden shed with a colander on her head, angry wingtip feathers brushing her armoury as the parents shrieked their displeasure.

Everyone remembers the time they were pooed on by a gull. The initial shock from the force of the splat is followed by an unpleasant wet sensation in your hair or down your back, a gut-wrenching odour, extreme embarrassment and an urgent need to clean it off. Although gulls are commonly thought to be opportunistic scavengers, feasting on the contents of bins, I can confirm the bird who pooed on me had been eating fish. Lots of it.

All is not well in the gull world, though. The breeding population of herring gulls is in decline. Nesting sites are becoming scarcer as folk, keen to ditch the colander headgear, install spikes and nets on their chimneys.

So next time those piercing eyes have designs on your lunch, remember it’s a tough life for a gull.