Photo by Neville Young

Dear Readers, every so often someone spots something unusual in Coldfall Wood, and at the weekend my friend Neville sent  me some snaps of what looks like sawdust distributed all over the ivy at the bottom of this dead tree. Well, I was flummoxed, but my friend Linda D suggested that I have a look at ambrosia beetles as the potential culprits. And what a revelation it was!

Oak Pinhole Borer (Platypus cylindrus)Illustration by John Curtis (1791–1862) from https://commons.wikimedia.org/wiki/File:Britishentomologyvolume2Plate51.jpg

The Oak Pinhole Borer is a UK example of an ambrosia beetle. These beetles have a symbiotic relationship with a fungus – the fungus is essential for the development of the beetle larvae, but the fungus itself only lives in the tunnels that are excavated by the beetle. Such a specialised relationship! So specialised, in fact, that the beetle has special indentations in its carapace where the fungus is collected when the beetle changes from a larva to an adult beetle inside the tree. This fungus is then transferred to a new tree.

Ambrosia beetles favour stressed, sick or dead trees, and the process starts when a male beetle excavates a tunnel a few centimetres deep. This attracts a female, and they mate on the bark. The female then enters the tunnel and starts to excavate a series of radial tunnels, inoculating the tunnel walls with the spores of the fungus as she goes. The male follows behind and kicks out the ‘sawdust’ or frass, which is what Neville saw.

The female lays her first batch of eggs after about a month of tunnelling, and will then continue to lay further batches over her lifetime, which can be two or three years. The tunnels can extend for up to two metres. The larvae only eat the fungus, but they may also extend the tunnels as they grow: later in their development the larvae have strong, powerful jaws. It takes them up to two years to achieve full adult size (which is only about 8 mm long), and when they are ready to pupate they excavate a chamber inside the tree. Sometimes several generations of beetle will occupy the same tunnel system.

The adult females produce a very fine, powdery frass, while that of the larvae is a bit coarser – a skilled entomologist can tell the difference.

By John Curtis – https://www.biodiversitylibrary.org/, Public Domain, https://commons.wikimedia.org/w/index.php?curid=10785198

The Oak Pinhole Borer is a native species, but it became much more common after the Great Storm of 1987, when no doubt all those fallen oak trees felt like a bonanza for the beetle. As the beetle mainly feeds in trees that are dead or diseased already it is not thought to do a lot of damage, unlike some other members of the family.

The relationship between the beetle and the fungus is one of those things that makes me wonder how on earth it all got started. Whatever the origin, it’s an ancient symbiosis, and one that often goes unnoticed. It’s always worth keeping your eyes peeled when you go to the woods, or indeed whenever you’re out and about. It’s surprising what you can spot in even the tiniest patches of habitat.

Dear Readers, yesterday was the anniversary of my accident, but today is the anniversary of my titanium implant, and honestly I think this metal deserves to be celebrated all over again. The alternative to becoming ‘bionic’ would have involved being ‘plastered’ from ankle to thigh for six months, with no guarantee that the bone would have knitted together properly. As it is, apart from a few scars, I wouldn’t know that I was marching about with a metal leg. Thank you, Whittington Hospital Orthopedic Department!

I remember laying on the sofa composing this piece, and getting more and more excited as I learned about this most exemplary element. We’d all be much worse off without it.

Onwards! Here’s a paean to titanium, composed last year.

Titanium crystal bar (Photo By Alchemist-hp (pse-mendelejew.de) – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=7329436)

Dear Readers, ever since I had a chunk of titanium inserted into my leg a few weeks ago, I’ve been curious about what exactly it is. It’s funny how something that was previously just a number on the periodic table (atomic number 22 and symbol Ti since you ask) is suddenly a significant part of my body. Or maybe I should say ‘more significant part of my body’, since it’s found everywhere – in rocks and water, plants and animals, Interestingly, it’s not thought to play any part in the biological processes of animals, but it may do so in plants – nettles, for example, may contain up to 80 parts per million of titanium extracted from the soil.

Titanium is what’s known as a transition metal (due to its chemical structure), and it isn’t found in its pure form anywhere in nature. Most titanium can be found in two minerals, rutile (where the metal is combined with oxygen)(TiO2)  and ilmenite (where the metal is combined with iron and oxygen) (FeTiO3). The discoverer of titanium, William Gregor, identified its presence in some black sand found in a stream just outside the village of Manaccan in Cornwall in 1791.  Gregor named the new substance ‘Manaccanite’, but was trumped by German chemist Martin Klaproth who decided it should be called ‘Titanium’ after the titans of Greek legend.

Rutile (Photo By Rob Lavinsky, iRocks.com – CC-BY-SA-3.0, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=10400387)

Ilmenite (Photo By Rob Lavinsky, iRocks.com – CC-BY-SA-3.0, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=10146603)

Why is titanium so special, though, and why has it ended up in my leg? Firstly, titanium doesn’t corrode, and secondly, it has the highest strength-to-density ratio of any metal. Hooray! This means that my leg won’t weigh a ton and won’t rust. Furthermore, it’s highly biocompatible – it isn’t toxic, and isn’t rejected by the body, which means that it’s used for many implants (hips, knees and wrists as well as legs). Sounds like that old children’s song ( I particularly like this version because there’s a child in a wheelchair, but beware, it’s a bit of an earworm).

Furthermore, titanium is capable of osseointegration (what a great word!) – new bone is laid down directly onto the surface of the implant, and because the metal and the bone have similar degrees of elasticity they should function as a single unit. Interestingly, it’s the inflammation that’s generated by having a foreign body inserted into the bone that kickstarts this process, one reason why my consultant told me not to use ibuprofen as a painkiller – because it dampens inflammation, it would actually hinder the healing process.

Future possible developments include 3D printing of prosthetics and implants to exactly match the requirements of the individual patient.

Titanium wrist plate and screws (Photo by By Wouter Hagens – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=16629524)

I did wonder if titanium is magnetic – I had visions of walking past a hardware store and suddenly having all the screws and nails flying towards my leg, like some kind of middle-aged, crutch-bearing superhero. But no. This is good because it means i can still have an MRI should I ever need one.

But enough about my leg! Titanium is also used for some very exciting applications. Back in the day when it was relatively cheap, Frank Gehry used it to clad the Guggenheim in Bilbao.

Guggenheim Museum in Bilbao (Photo by By losmininos – El Guggenheim vizcaíno., CC BY-SA 2.0, https://commons.wikimedia.org/w/index.php?curid=40395018)

The SR-71 ‘Blackbird’ surveillance plane was built using 85 percent titanium – this was during the Cold War period. Ironically, the US didn’t have enough titanium to build it, so they actually imported rutile ore from the USSR, using a network of bogus companies and US-allied developing countries. The plane flew from 1964 to 1990, covering the wars in Vietnam and Laos and repeatedly flying over the USSR to gain information. It was a remarkable plane – it achieved an altitude of over 85,000 feet in sustained flight, and a speed of 2,192 mile per hour. I saw one at one of the airforce museums (Duxford? Cosford?) and it’s a very impressive beast, matt black and strangely sinister. One interesting point is that the panels that make up the plane don’t fit precisely when it’s on the ground – the panels expand when exposed to the huge heat generated on take off, so they then slide into place.

Sr-71 ‘Blackbird’ (Photo By USAF / Judson Brohmer – Armstrong Photo Gallery: Home – info – pic, Public Domain, https://commons.wikimedia.org/w/index.php?curid=30816)

However, most of us will have been using titanium without even realising it – because it’s both lightweight and strong, you can find it in cycle helmets, golf clubs, tennis rackets, and bicycle frames. It’s often found in camping cookware (easier to carry) and horseshoes. Many dental implants contain titanium, for the same reasons as the medical uses outlined above. What an extraordinarily versatile and yet unappreciated metal it is, and how lucky we are to have it.

One strange thing that occurs to me, though, is that this metal will live on far longer than any of the other parts of my body after I’m dead. I wonder, can they recycle it, like the rest of me will be recycled? Apparently recycing is possible if I’m cremated – the metal is separated from the ashes and can be collected by an organisation called Orthometals, provided the crematorium is signed up to the scheme. I shall have to write a quick codicil to my will. Metal is too precious to waste, although the titanium won’t be pure enough to be used in another implant – it will probably be used in some kind of industrial process. That’s good enough for me!

Dear Readers, I am walking along East Finchley High Road when I see a crow flying off with what looks like a little bag in its beak. Instantly, a young man sitting on a bench nearby leaps up and runs after it.

“Blimey”, I think, “Did that crow steal the man’s lunch or something?”

And then I get to the ‘lawn’ in front of the block of flats, and there, in the grass, is a baby wood pigeon.

I look at the man, and he looks at me, and we both look at the pigeon, who is blinking in the sunlight. The crow is circling overhead.

Both of us humans are a bit unsure about what to do.

“I have racing pigeons,” says the man, “and I could just pop the baby under one of my hens, but then he’ll grow up thinking he’s a racing pigeon”.

I had never noticed how big the beaks are on young pigeons. The crow comes a bit lower, and the pigeon tilts his head to look at his nemesis.

“If you hop over the fence and pick him up, I’ll try to get some help”, I say.

And two minutes later I’m heading for home with a baby pigeon in my hands. The nestling seems relatively calm – I can see that there are the first signs of wing feathers. A few more weeks and he’d have been big enough to leave the nest.

I pop into the RSPCA shop – they run around trying to find a box to put him in, but have no contacts to help, although the man behind the counter is very kind and empathic.  I know that vets generally can’t/won’t help with wild animals either (with some notable and honourable exceptions), so I call in the hive-mind on our street.

One of my neighbours fosters cats, and is a great source of all things animal-related. Within minutes she sends me a phone number. The person that I call puts me in touch with a lady who is involved with London Wildlife Protection, a group who rescue pigeons and other birds all over London.

I talk to Babs, who says she will take ‘the little woodie’. She lives close to Old Street, so we agree to meet at the Northern Line station.

Little Woody has what must be a most surprising trip in a box to Old Street, where Babs appears on a bike with a backpack where she’s constructed a little ‘nest’ for Woody.

“Will you let me know how he gets on?” I ask, but she grimaces.

“I’ve got 4 already, and I’m so busy with them”, she says. “And he’ll be passed on to a rehabber with an aviary so I won’t have him for very long. ”

I understand. Who wants to be sending texts and stuff when you’re up every hour feeding baby birds? Much better that the birds are looked after.

” He looks good, though”, she says. “He’ll survive”.

And so she pedals off, and I head for home, thinking about how everyone has tried to save this little bird, from the man with the racing pigeons and the man in the RSPCA shop to my neighbour, to the network of bird rehabbers. What a complicated species we are, bombing the life out of one another on the one hand and yet coming together to save a pigeon on the other.

Norman Foster’s design for the Queen Elizabeth II Memorial in St James’s Park – the ‘Tiara Bridge’

Well, Harrumph readers – the Norman Foster design for the Queen Elizabeth II memorial has won the competition that I blogged about here. How very uninspiring, especially compared to my/our favourites the J.L Gibbons entry, with its planting plans and use of rock, and the Wilkinson Eyre with its interesting pathways. 

Well, I suppose that Foster has a lot of experience of building ‘stuff’, and he is 91 so it’s a way of honouring him. But I do feel it’s a missed opportunity. Do we need another equestrian statue of the Queen? Or what looks like a fairly scary statue of HM and Prince Philip? Hey ho. I guess none of it will scare the horses.

Yinka Shonibare’s Wind Sculpture looks interesting – judging by his previous work, it aims to ‘capture’ the idea of the wind. Shonibare was born in East London but grew up in Lagos, and generally his work combines influences from both places. Let’s see what this looks like when it’s finished.

Yinka Shonibare’s Wind Sculpture

Foster is known for the Gherkin and the Millenium Bridge and for what I think is one of his most successful re-imaginings, the Great Court at the British Museum, so he has ‘form’ for building interesting and controversial structures. I will be fascinated to see how the Memorial takes shape.

Arrowhead the tigress, Ranthambore, India (Photo by Sachin Rai)

This week I learned of the death of Arrowhead, a tigress who had ruled the territory around the lake and old castle of Ranthambore for many years. She was the grand daughter of Machli, a tigress that I ‘met’ with her two cubs when I visited the reserve nearly twenty years ago. Of the animals I have been privileged to see, she was the most charismatic – the air seemed to have a different texture when she was present. It felt incomprehensible, extraordinary that such a creature walked the earth. It is even more incomprehensible to me that we are wiping them out.

The Tyger is often seen as a poem for children, but reading it as an adult is a different experience. See what you think.

The Tyger

Tyger Tyger, burning bright,
In the forests of the night;
What immortal hand or eye,
Could frame they fearful symmetry?

In what distant deeps or skies
Burnt the fire of thine eyes!
On what wings dare he aspire?
What the hand, dare seize the fire?

And what shoulder, & what art,
Could twist the sinews of they heart?
And when they heart began to beat,
What dread hand? & what dread feet?

What the hammer? What the chain?
In what furnace was they brain?
What the anvil? what dread grasp,
Dare its deadly terrors clasp?

When the stars threw down their spears
And water`d heaven with their tears:
Did he smile his work to see?
Did he who made the lamb make thee?

Tyger Tyger, burning bright,
In the forests of the night;
What immortal hand or eye,
Dare frame they fearful symmetry?

William Blake (1757 – 1827)

Perennial Sowthistle (Sonchus arvensis)

Dear Readers, my friend A sent me the photo above. 

‘What’s this triffid?’ she asked (the plant looks as if it’s about the height of a primary-school child).

Well, it turns out that it’s a Perennial Sow-thistle, also known as a ‘dindle’, though why I have not yet been able to ascertain. To dindle meant ‘to vibrate or tingle’ . When I Google the word it keeps presenting me with ‘dirndl’, which is one of those Tyrolean long skirts, worn with a lacy apron, and is not at all the same thing. Like all members of the Sowthistle genus, the milky sap was believed to improve lactation when eaten by domestic animals, particularly pigs.

It’s certainly an impressive plant, and it’s one of the ‘yellow Asteraceae’ that we were told not to try to identify when I went on a field course about twenty years ago – what with all the hawkbits and hawksbeards and nippleworts and dandelions it’s a very tricky family. But this one is pretty clear – it has nice shiny leaves, several large yellow flowers on each stem, and while it produces white latex like so many plants in the family, it doesn’t turn orange, which that of the Prickly Sowthistle and Smooth Sowthistle does.

Leaves of Perennial Sowthistle

Perennial Sow-thistle (Illustration Public Domain)

The Botanical Society of Britain and Ireland (BSBI) describe Perennial Sowthistle thus:

‘This patch-forming, horizontally spreading perennial, with its stems up to 150 cm tall, is very conspicuous and unmistakable as it waves to the passing motorist from the roadside verge from late July through to October as it bears its large, bright yellow, dandelion-like flowerheads.’

I very much like the description, although ‘our’ plant is clearly a bit early. The BSBI go on to say that although the plant  is classed as a dangerous weed in many countries, in the UK many of the seeds are eaten, particularly by beetle larvae, and of the rest only about 40% are viable. However, as each plant can produce 13,000 seeds per season, and as the plant can also reproduce via rhizomes, it can quickly grow into a clump if the conditions are correct. On the other hand, it looks to me to be rather more attractive than most of the other sow-thistles, which often look very knocked-about by the time all the leaf-borers and mildews have had a go at them. Plus, all manner of pollinators love the flowers.

Photo by Phillippe Juillerat at https://www.infoflora.ch/en/flora/sonchus-arvensis-subsp-arvensis.html

My friend A, an inveterate forager, was also curious as to whether the plant was edible. My initial reaction was ‘no’ because of the white sap, but then  dandelion leaves are perfectly safe to eat (if not grown where they can be contaminated by dogs or pollution), and indeed the leaves of this plant, too, are said to be bitter but fine in a salad, particularly when young. You can find a few recipes here. One legend has it that Theseus feasted on sow-thistle before he entered the labyrinth to do battle with the minotaur.

On the other hand, while many creatures eat the leaves of the Perennial Sow-thistle, one of the rarest and most spectacular is the caterpillar of the Striped Hawkmoth (Hyles livornica). The adult moth is an immigrant which lays its eggs on a variety of plants, but particularly Perennial Sow-thistle. The caterpillars don’t often survive the winter (yet) but are well worth looking out for, with their black and yellow livery and natty red ‘feet’.

Striped Hawkmoth(Hyles livornica) – Photo by By Hectonichus – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=12673640

Caterpillar of the Striped Hawk Moth (Photo By picture taken by Paolo Mazei – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=6346422)

Like many plants that produce milky latex, Perennial Sow-thistle also has a reputation for curing warts if the sap is applied to the area in question. In Wales, it was believed that carrying a sow-thistle leaf in the hat or belt would protect the person from ‘the devil, witches and hags of the night’. On the other hand, a person wearing a leaf could walk and never tire, although anyone walking alongside would tire more quickly and eventually die, which seems like a bit of a rum bargain if you ask me.

And here is a poem by Irish poet Annemarie Ní Churreáin. I rather loved it. See what you think.

Sow-thistle by Annemarie Ní Churreáin

at St Joseph’s Industrial School, Dundalk, Co Louth (1881-1983)

Here, in the aftermath of the orphanage,
I watch the local schoolgirls gathering
along the street’s chipped, black railings
and, two by two, link slender arms to troop
uptown against the sun, all high heads
and clear temples, all grit and burning,
all clean hair flashing ponies.
Who knows the earth more than a girl?
Who knows the auguries of stone?
We were often told, you are the lowest of the low,
we cupped our hands to the grass to see how low.
What cannot be written is rising up
through the cracks. I kneel to a sowthistle,
leaf-starred and gold between my fingers,
the stalk throbbing light. I encounter
its living testimony, as closely as I
would encounter the expert findings
of any state report.

Photo by Françoise Alsaker at https://www.infoflora.ch/en/flora/sonchus-arvensis-subsp-arvensis.html

Well, Readers, East Finchley Festival was a really lovely event – the temperature dropped a bit from Saturday’s high of over 90 degrees Fahrenheit (32 degrees Celsius for you new-fangled people), which was just as well – with the humidity it felt like being back in the rainforests of Cameroon. We hadn’t expected it to be windy (doh) so at first we were all hanging on the gazebo for grim death. I expected to be whizzed off over the rooftops like Mary Poppins, but fortunately some tent pegs were found, and we could get back into trying to sell raffle tickets.

We had lots of donated books and some seedbombs as prizes, along with three ‘mini-meadow’ window boxes. I got a selection of plants from Naturescape (an excellent company by the way) and they contained an interesting variety of plants, including harebell, self-heal, knapweed and betony, a new favourite. There were also a couple of native primroses, which were going over a bit, but would be ok for next year. It was lovely to see my ‘babies’ going off to new homes.

A new thing for this year was some Friends of Coldfall Wood business cards – these are impregnated with wildflower seeds, so (having carefully written down the details of course) you can pop the card into a flower pot, give it a water and Bob’s your proverbial uncle. Visitors to the stall were so delighted, and it’s great to be able to give people just a little thing to take home and to remember us by.

The Festival itself is very much a community affair: our friends from Friends of Cherry Tree Wood were on the stall next door and on the other side we had Muswell Hill Sustainability Group, so there was lots of green space/environmental stuff going on. But there was also food from all over the world, stalls selling all manner of handicrafts, and two stages – one for community choirs/dance groups/children’s groups, and one for ‘bands’. So it was all pretty busy, and frenetic, and full-on, but a lot of fun. And it’s true that East Finchley was voted ‘The Happiest Place in London’, even if it was ten years ago. It seems to me that nothing much has changed. I count myself very lucky indeed to live here.

The person that I felt sorriest for, though, was the person in the elephant costume, who led the parade that kicked off the Festival. Greater love hath no person than to be enclosed in a claustrophobic fur outfit on a hot summer’s day. Well done!

Lemon Ants (Myrmelachista schumanni) Photo from https://the-most-exteme.fandom.com/wiki/Lemon_Ant

Dear Readers, I received a comment a few days ago from someone who had accidentally nearly eaten an insect of some kind. They described how it tasted of cinnamon, and I was instantly intrigued. On a holiday to Costa Rica many years ago, I tasted a lemon ant (sorry!) and was surprised at how ‘lemony’ it tasted – formic acid is presumably chemically similar to the citric acid in citrus fruit, so maybe it isn’t that unlikely. But when I started to look into the natural history of the Lemon Ant, I found that they used their formic acid for something much more interesting than dissuading predators (except humans, clearly) from eating them.

Lemon Ants create ‘devil’s gardens’ – these are areas where all the natural biodiversity of the rainforest has disappeared, leaving nothing but the ants and three species of tree. One of them is Duroia hirsuta, and it plays a very special role in the life of the ants.

Duroia hirsuta fruits (Photo by Karsten Thomsen at https://www.flickr.com/photos/94052068@N06/9124372155

Firstly, the plant itself produces chemicals which deter other plants from growing close to it, but this is greatly aided by the ants, who  inject other plants with their formic acid and make sure that nothing else can grow around the Duroia trees. Lemon Ants are the only insects known to use formic acid as a herbicide. The Lemon Ants also kill any other ant  species which would otherwise harvest the leaves of the tree, and will usually nest in a Duroia tree, as well as eating its leaves.

The devil’s gardens that the ants create can be enormous – the largest garden ever found contained over 300 trees over an area of 1,300 square metres, and was estimated to be 800 years old.

Although the Duroia trees have to put up with having their leaves eaten by the ants, there is a clear overall benefit to the plants: in the absence of ants, 94% of Duroia trees die. The trees benefit from having the competitive plants around it killed by the Lemon Ants, and also by the elimination of other invertebrate species who might munch on the leaves. The waste from ants’ nests can also be an important source of nutrients for the tree. In return, the Duroia trees offer food, and a place to nest. This is a relationship that has probably been ongoing since the Cretaceous period, 108 million years ago. There is still so much that we can learn about the complex interrelationships of different species.

And next time I’m offered a lemon ant, I shall definitely pass.

Photo by Paul Gavinger at https://www.flickr.com/photos/highlyecumenical/52796500456

Dear Readers, you may have noticed how much of our discarded ‘stuff’ seems to end up in birds’ nests and squirrel dreys. Scientists have been intrigued about what is selected and why for some time now – for example, magpies and crows have been spotted ripping the anti-pigeon spikes from buildings and incorporating them as a kind of spiky armour in amongst the twigs and leaves. However, scientists found birds using many other kinds of human-made objects in their nests, and speculated that corvids, notorious egg thieves, might be neophobic – afraid of new things – and that this might give the parent birds more time to defend their nests from the marauders.

Large feathers are also often found in nests, and one theory was that this looked as if a bird had been killed at the nest site, deterring nest predators from approaching.

Scientists Magne Husby and Tore Slagsvold, both from universities in Norway, constructed three kinds of artificial nests. One just contained quail eggs, one had eggs plus a shiny spoon, and one had the eggs plus large feathers. They then trialled the nests in a forest to measure the responses of magpies, and at a landfill site to measure what ravens did.

Magpies waited 96 hours before taking eggs from an ‘ordinary’ nest, 149 hours before raiding the nest with a shiny spoon, and 152 hours before checking out the nest with feathers. Ravens were much less hesitant, but still took 28, 34 and 43 hours respectively.

There is a substantial difference in time of predation between undecorated and decorated nests, and it intrigues me that birds are adapting to our ‘rubbish’ in this way. However, I do wonder – corvids are very fond of shiny objects themselves, so I’m surprised that the shiny spoon wasn’t more of a draw than anything else. As with everything else in nature, we may underestimate the effects of individual personality and choice, both in the parent birds and the egg thieves. This isn’t the end of the story, I’m sure.

You can read the Royal Society paper here.