Nature Notes 2019

December 2019

The Holly and the Ivy

Butterflies and Christmas do not spring to mind as a natural association but there is a fascinating link.

Ivy is nowadays only tenuously tied to the festive period although you might like to know that it was believed to relieve the unpleasant effects of too much alcohol, and the Christmas carol, with its beguiling line asserting that between the two of them, the holly bears the crown, will forever perpetuate an association.

A holly tree is either male or female - dioecious to the botanist or gardener - and since the fruits are borne by the female, only the fairer sex has the succulent looking red berries. She needs a nearby male holly though, and insects as go-betweens, to carry the pollen to the stigmas in her tiny flowers.

The scarlet berries on a sprig of evergreen, glossy leaves are a timeless link with the mid-winter festive period and the association predates all Christian ties. The thorns of the leaves and Christ's thorny crown, the red berries representing the blood, shed at the crucifixion; these ideas were invented long after the pure appreciation of an attractive winter-green plant had brought comfort and joy to the pre-Christian mid-winter festival.

Holly is quite a popular garden plant locally and not uncommon as a self-sown tree in woods and thickets hereabouts. In parts of Epping Forest and the Welsh Marches, there are Holly woods and in Suffolk a tree that is 22 metres tall with a girth of more than 2 metres.

Ivy however provokes mixed feelings. It is one of the most useful plants that a gardener can tolerate if wildlife is a consideration as it produces safe nesting sites for a variety of birds, provides copious late-summer nectar, lapped up by bees, butterflies and hoverflies and the fruits are the favoured food of second-brood Holly Blue butterflies.

Through the winter, this cheering butterfly will be passing its time as a chrysalis – presumably in the soil beneath an ivy-clad tree or out-building but as far as I am aware, no-one has ever knowingly found one in the wild.

The adult emerges quite early in the year and flies in April and May. It is the most likely blue butterfly to be seen in a garden unless yours is a wild-flower meadow with vetches, and the Holly Blue spends little time near the ground as it skips over hedges and meanders between bushes. In the spring the female, after finding a mate, will be searching for a female holly bush for the caterpillar feeds on the developing fruits. This generation spends only a few weeks as a chrysalis and a second generation is on the wing in August completing the link by favouring ivy as its food-plant of choice.

Here in the north Midlands, the Holly Blue was virtually unknown until the 1980s but it has spread northwards with climate change, though in some years there are far fewer of them because of another association, this time with a parasitic wasp.

This ichneumon wasp, Listrodomus nycthemerus has no other host and lays an egg in the caterpillar which the emergent larva consumes from within. When wasp numbers are high a great many butterfly caterpillars are killed and then both species reach a low ebb but the butterfly's population recovers in a few generations with the wasp's numbers lagging behind. Every 4 to 6 years the wasp becomes abundant and the Holly Blue's numbers crash.

An abundant crop of red berries on the holly sprigs gathered for Christmas is usually said to follow warm, wet springs but I wonder if the population cycles of the Holly Blue butterfly have a significant effect too?

November 2019

Elms

Dutch-elm disease ravaged our countryside in the 1970s.

I don't think 'ravaged' is too big a word to describe what happened, because the loss of mature elm trees in our hedgerows and lanes altered the appearance of the rural landscape in a way that historians of the future, examining photographs and paintings, will be able to use as a way of determining a point in time.

The disease was identified by Dutch scientists (hence the name) in 1818 and it was widespread in Britain by 1928. However the disease then, was rarely fatal and many trees recovered. The demise of the elm in Britain began about 1970 when a more virulent strain of the disease reached this country having arrived here from North America and Canada.

The disease is caused by a fungus which is transmitted by the Elm-bark Beetle Scolytus scolytus. The beetles breed in dead and dying elms where the larvae tunnel beneath the bark, forming characteristic chambers from which the adult beetles emerge after having been contaminated by the fungus and they then fly to healthy elms. Here, they feed on young bark and pass on the fungus to the tree. This fungus, now called Ophiostoma nov-ulmi gets into the conducting tissue of the tree (the xylem) where it blocks the flow of water and nutrients and the tree rapidly wilts and dies.

Depending on which taxonomist you ask, there are from 2 to 7 species of elm and the Midlands have much variety, but the two most common ones are English Elm and Wych Elm and both can be found in roadside hedgerows in south Notts. This is because the rootstock throws up suckers after the tree has died and sometimes these will grow to around 5 metres or more before they are killed off again.

Five metres is nothing like the 35m or so that the English Elm used to achieve. It was a majestic tree and characteristic of the English countryside with a distinctive layered canopy when mature and readily identifiable from photographs and landscape paintings.

However, despite being native, it wasn't always common; it was in the 18th and 19th centuries that it became popular and landowners planted it widely. They favoured particular characters and most of the saplings were cloned from the same tree. Hence there is little genetic variety in the English Elm which makes it so vulnerable to Dutch Elm Disease.

Another iconic tree, the Ash, is now in the firing line with Ash Dieback, caused by another fungus and careless importation of infected saplings, taking its toll, but there is hope that this species, which grows readily from seed, has enough variation for some trees to survive. Early indications locally, are that although many saplings are being killed, mature trees are unaffected.

It was feared that, with the demise of the elm, a rarely seen butterfly, the White-letter Hairstreak, which depends on elms as the larval food-plant would also disappear but they are able to make use of the suckering regrowth and are surviving well.

Our farmed countryside was largely created during the late 18th century with the Inclosure Awards when our hedgerows and modern lane layouts were determined. Along the hedges, Ash, oaks and elms were planted to provide shade and structure to the landscape but with the mature elms gone, the Ash dying of old age and threatened by dieback and the oaks also now aged and with their own threats, the fields are becoming treeless.

This is not helped by the tractor-mounted flail! An obsession among landowners to trim hedges every autumn as though they were ornamental gardens deprives wintering thrushes of a valuable berry food-source, deprives Yellowhammers and Whitethroats of nesting habitat and deprives seedling trees the opportunity to grow up into the majestic structures that were once so appreciated in our countryside.

October 2019

Papillon de Nuit

Butterflies of the night are what the French call moths. The rather dowdy sounding word 'moth' does not do these lepidoptera justice and anyway, the distinction between butterfly and moth is purely artificial and it is meaningless to attempt to define one. Butterflies are just 6 families of 'scaly-winged' (that's what lepidoptera means) insects, among 74.

Some moths look a lot like butterflies and vice versa; the Magpie Moth looks a lot like what people think of as a butterfly – it has broad, gentle wings with pretty markings and a slender abdomen whilst the Large Skipper butterfly holds its wings in a strange posture, flies fast and has antennae that are only slightly swollen at the tip – a lot like many moths.

True, the Magpie moth is nocturnal and the skipper is diurnal but lots of moths are day fliers and some don't mind whether the sun is out or zillions of more distant stars are up in the heavens. I occasionally have butterflies attracted to my moth trap.

Moths are easily recorded with a moth trap, which as you might expect is a light trap that attracts the moths and keeps them till the morning. Victorian entomologists didn't have the luxury of electricity and had to find their moths by other means, like searching for their larvae in the countryside or attracting them to sugary solutions painted onto fence posts and tree trunks.

There are lots of people who, like me, run a garden trap regularly and submit their records for analysis by professional entomologists. A national atlas of moth distribution is due for publication soon. It will be based to a large extent on the identifications made by garden moth trappers.

Since 2004, I have recorded the amazing total of 454 species of moth and that compares to just 16 of butterflies. One of those 16, has not been seen for about twenty years as the Wall Brown, once common and widespread has now disappeared completely from Nottinghamshire though they are hanging on in parts of Derbyshire. Two other species are relative newcomers; Speckled Wood and Holly Blue have expanded their ranges.

The changing fortunes of moths has also been reflected in my Keyworth garden with my first record of our largest moth, the Privet Hawkmoth in 2007 presaging their annual visits since. With a wingspan of 120mm, this is an impressive insect but it begins life as a spherical egg with a diameter of just 2mm from which the tiny caterpillar hatches.

I found a hatchling on my trap on 21st July this year and kept it in the kitchen with a supply of fresh privet clippings and watched it grow – slowly at first but then exponentially until 24th August when it was a whopping 85mm, and it buried itself in the bucket of compost provided for the purpose. It will pupate there, in a cool outhouse, and undergo its amazing metamorphosis and I hope to see it again around next June as an adult moth – known in the trade as an imago or perfect insect.

I've reared moths many times with my family's help, and it is great fun. It is also educational fun and it is possible to buy a kit aimed at children with the necessary materials to rear what I think are often Painted Lady butterflies. It is much cheaper though, to find a marching caterpillar at this time of year for it will almost certainly be looking for somewhere to pupate and if you provide it with a small bucket of compost covered with muslin, a similar result should be achieved for no expense.

September 2019

The Future

I was a young person once; I was about to enter the world of work and I was concerned for the future of our planet and depressed about the prospects for the wildlife of the world having watched TV programmes that always ended up with a footnote about how all the wonderful wildlife that had just been shown, would soon be lost without immediate action.

Half a century on and many species have become extinct, however, none of them have been 'flagship species' such as Tiger or Polar Bear, though the demise of the latter, in the wild at least, is now ever closer.

I have had the pleasure to meet some wonderful young people in the last few years through my connection with the Rushcliffe Barn Owl Project. This initiative brings guest helpers into contact – literally- with a magnificent wild bird species as they assist in their conservation.

I have gone on to show some of them the plants and invertebrates to be found at our local nature reserves; Wilford Claypit, a Notts Wildlife Trust reserve is a favourite, and the few hours that I have spent in their company, witnessing their delight and enthusiasm for our modest flora and fauna (there are no flagship species here any more - their local extinction took place a few centuries ago) is an absolute pleasure, and a reassurance that in the age of distracting devices, some people still value reality.

And they realise that the reality of mass extinction is ever closer.

There are so many threats; habitat loss, increasing human population, poaching, mechanised farming, global heating – the list is endless and the consequences are not just to wildlife but to life in general – ours included. Young people are realising it. Yet we are continuing to live our lives pretty much as usual. In the climate modelling world this is called 'business as usual' and is the worst case scenario. It is 20 years since I studied climate change and nothing has changed.

Buying a bag for life rather than 10 single-use bags is not going to make the lives of our grand-children any better. We need to change. We need to be led by governments around the world who appreciate reality and value the lives of future generations.

I feel like I'm on a steam train and the coal in the firebox is being allowed to burn out rather than have anyone pour water on the fire and apply the brakes.

Leonard Cohen saw the future; 'it is murder'.

August 2019

Grass Snake

There are three species of wild snake in Britain but only one now in Nottinghamshire: Smooth Snakes have never occurred here and there hasn't been a reliable sighting of an Adder for some years (as far as I know, though because of the danger of persecution, reports may be being withheld). They were present at one location in the Sherwood Forest area up until the early years of this century.

Grass Snakes however, are surprisingly common in south Notts where there is permanent grassland and water and they often find their way into gardens that are not too distant from open countryside – especially those with ponds.

In 2017 DNA research concluded that there are two species of grass snake in Europe and ours became Natrix helvetica with the common name of Barred Grass Snake though I think it will remain just plain old Grass Snake for a long time. Our species lives over most of western Europe whilst Natrix natrix occurs to the east of the Rhine.

I feel certain that their Nottinghamshire distribution and population is far higher than official records suggest because casual sightings are rarely reported, whilst when they are looked for, they are remarkably elusive.

Adders give birth to live young and Grass Snakes lay eggs. These need to be kept warm and the snakes don't incubate the eggs (a female can lay as many as 30 to 40) so compost heaps are a popular place for them to use because of the warmth generated. The hatchlings are only about 15cm long and as thin as a pencil but females can eventually reach 120cm though the males are somewhat smaller.

They are of course, completely harmless to anything bigger than a frog – their favourite prey, which they will take while swimming - and if you are quick enough to pick a Grass Snake up, they will often pretend to be dead. They will also give off a rather unpleasant smell from glands near the anus which is best avoided but, if handled gently, they quickly become accustomed to this new experience and will glide through your hands like a pet snake.

As they grow, they slough away their old skin revealing how beautiful they are with their glossy olive scales and a yellow collar. I once had one swim out of a pit at Barnstone while I was angling and curl up next to me for a twenty minute snooze in the sunshine – a lovely, memorable experience.

July 2019

"Weeds"

A brightly clad chap on a quad bike has just been along my street. It said on his hi-viz jacket “Weed spraying in progress”. In the USA people are being awarded large sums of money as compensation for cancer caused, it seems, by glyphosate – almost certainly the chemical now distributed along our street channel and pavements - though the safety concerns of the public is not my reason for taking to the keyboard.

It's the obsession with our dominion over nature that narks me and which suggests that despite all the David Attenborough programmes and the alarming publicity about the imminent great extinction, our attitude to nature is unchanged.

The framework of our countryside is man-made – there are no natural landscapes anywhere except around our coasts where the cliffs are pretty much as they would be without man's presence and the salt marshes though squashed in by sea walls, harbour a representative flora – with some exceptions.

But the fields, woodlands, uplands, heathland, and rivers are all quite different to how nature intended.

Our urban regions bear no resemblance to what went before but nature does put up a fight – though it is a bit of a weed when push comes to pull – by attempting to reclaim these 'man-scapes'. A dandelion takes a stand here, a bit of groundsel on the flanks. Perhaps some prickly sow-thistle hides, like a sniper in a hedge bottom hoping to fire off some seeds or a patch of ivy-leaved toadflax attacks on a broad-front along an old wall.

We give them a glimmer of hope but then it all becomes too much for us. Spray them. Yank them out. Fight back – that's what we do.

What you do in your own garden is your business, not mine but all these so called 'weeds' are wild flowers – many of them native to this country (and many introduced by man) and are constituents of nature – the stuff that Sir David raves about. Please begin to appreciate them and hold back on the glyphosate. Get more relaxed about having some nature in your backyard because all those 'weeds' support a link or two in the chain of wildlife that we all ultimately depend upon.

June 2019

Corncrake

My father used to tell me of the song of Corncrakes that he said dominated the nocturnal landscape of his rural childhood. Born in 1916, he was among the last generation in England to have been kept awake by their peculiar, loud and repetitive call for they had been in decline for several decades by then and were effectively extinct in England by 1950.

This is a ground nesting species that was abundant when cereals and grass were mown by scythe as the stately progress of the scything teams gave the birds ample time to find a safer location. Although they are long-distance migrants, wintering in tropical Africa and so perfectly able flyers, they are reluctant to do so on their breeding grounds and prefer to skulk in the vegetation where they rely on their brown and grey plumage. With the introduction of scissor cutters drawn by horses the fields were mown in a fraction of the time, starting at the field perimeter and spiralling steadily inwards until the Corncrakes and other wildlife including Harvest Mice had been corralled into the centre and then butchered wholesale by the blades or crushed under the cutter bar.

In the early part of the twentieth century, there were plenty of flower-rich meadows and weedy arable fields holding abundant invertebrates for the crakes to eat but cereal fields are now largely weed-free so plants that were once common such as Pheasant's-eye and Shepherd's-needle are now very rare and we have lost 97% of the flower-rich meadows. They have been 'improved' to yield an abundance of grass (which is after all their purpose) without the weeds like Ox-eye Daisy, Red Campion, Hay-rattle and Ragged Robin that so delighted the eye in May and June.

Attempts to create a wildflower meadow in Keyworth have failed despite an encouraging start. The field was prepared and seeded in 2011 and in 2013 was looking wonderful but over successive seasons the diversity fell and in 2018 it was dominated by False-oat Grass; the common one on roadside verges. This is because of the high nutrient levels in the soil – the desired wild flowers cannot compete with those that love nitrogen.

This is why the fields up until the second world war were so floriferous; the farmers kept removing the hay and not putting anything back so the nitrate levels fell and the vetches, mayweeds and cranesbills thrived.

Some of the best wild flower meadows left in Britain are the machair on the Outer Hebrides where Corncrakes still survive despite being globally threatened.

May 2019

Pondlife

There are few things more pleasant than lying down next to a pond full of crystal clear water, thronged with aquatic plants and alive with bugs and beetles. Occasionally a newt will wiggle to the surface, take a plug of air and dive out of sight. Pond skaters skip across the surface and whirligig beetles whizz around like fairground dodgems speeded up a thousand times.

A frog's face dappled with shadow and duckweed appears among the lily pads. A dragonfly may hawk over the pond and perhaps settle close by.

With the spring sunshine on your back, you can imagine the world drenched in wildlife, for ponds, when in pristine condition, are among the richest wildlife habitats to be found in Britain.

Sadly, they are not needed much now, in a farm-scape dominated by arable rather than mixed farming and they are generally neglected, allowed to silt up and often filled in because of their inconvenience to large machinery.

So garden ponds are really important and they don't need to be big or grand as even the smallest and shallowest will provide habitat for some creatures and a place for birds to drink and bathe.

New ponds take a while to settle down and for the algae, that will inevitably arrive, to clear. Some plants will dominate and grow rapidly but these can be hooked out and make good compost and soon the water will lose its green hue and Tom from the Water Babies would find it irresistible.

Children love supervised pond-dipping but if you don't feel comfortable with a pond and kids in the same garden, look out for sessions arranged by Nottinghamshire Wildlife Trust or take the children aged 8-12 along to a Watch group – see https://www.nottinghamshirewildlife.org/wildlifewatch.

If you are tempted to build a pond, please try to stock it with native plants. You won't need many and those that don't like the conditions will soon fail whilst those that do will find their own way in – as will the invertebrates – within minutes of filling the pond there will be creatures taking advantage of your efforts.

I built my own garden pond over thirty years ago and once, when it needed some maintenance I counted about 130 common newts. It has attracted herons, dragonflies, china-mark moths and children over the years and I wouldn't want to be without it.

April 2019

Peewits

Until the late 1980s, the ploughed fields of south Notts were home to big flocks of plovers; Golden Plovers and Lapwings were often up to 500 strong with the latter usually the most numerous. Cold-weather movements of similar numbers of Lapwings was a common sight. There are very few Lapwings nowadays and they are mostly confined to the Trent valley gravel pits whilst Golden Plovers are all but absent.

Lapwings have many local names, Peewit being an onomatopoeic rendering of their song which they give out whilst displaying over their breeding territory during their captivating song flight in which they twist and turn in a manner that seems extraordinary for a bird that has such broad, rounded wings.

From a distance they seem black and white but with good views in sunshine, the upper-parts are seen to be iridescent green, hence another name, Green Plover. Capped with dashing crest feathers, I think they are one of Britain's most spectacular birds.

Their eggs used to be a popular dish and in the 1820s a single collector was sending more than 600 eggs a week to London markets giving an indication of how rich the countryside was prior to intensive agriculture. It seems impossible to believe some of the statistics of wildlife numbers from long ago but in my lifetime I have witnessed the decline of so many once common birds and insects that Victorian descriptions of clouds of butterflies in the New Forest can be no exaggeration. A visitor in 1892 recalled Silver-washed Fritillaries in such numbers that she could hardly see ahead and that they resembled a fall of brown leaves.

Long-term documentation of wildlife, especially moths and birds provide clear evidence that perceptions and anecdotal accounts are reliable. I can remember the 'moth snowstorms' in car headlights and the splatter of insects on windscreens that people much younger than me perhaps can barely believe. No wonder the pre-migration gatherings of Swallows and House Martins, shoulder to shoulder along hundreds of metres of overhead wires are also a thing of the past.

March 2019

Silverfish

Early 2019 found me confined to the kitchen, undertaking a long overdue revamp; the culmination of a lifetime's dabbling at DIY, so not much in the way of wildlife encounters to prompt an article, though there was one little beastie that I came across during the destruction phase.

I first encountered Silverfish in 1971 at a house in Colchester where I was a lodger and though I'm sure my landlady kept a clean and hygienic home, they did seem to be a permanent guest and I found them fascinating.

Silverfish are very primitive insects and the commonest species in the order Thysanura, the Three-pronged Bristle-tails. They like the dark and hide away in nooks and crannies during the day (until some DIY-er comes along and destroys them). They also like starch and sugar so kitchens, pantries and bakeries are favoured though I've come across them in bathrooms too.

They are perfectly harmless; they do not harbour or spread disease to humans but their appearance and behaviour might come as a surprise to anyone seeing Silverfish for the first time. About a centimetre long and shaped like a carrot, and they are of course silver coloured. They dash about like a slippery fish, so their name suits them perfectly – though it might create confusion.

Nearly all insects change in appearance as they grow older: caterpillar – pupa – butterfly for instance or in the case of Odonata, water-delling nymph to adult dragonfly but the Silverfish starts out as a tiddler and just grows bigger: It hasn't evolved wings and has maintained its appearance and presumably, behaviour for 400 million years since the early insects developed. If there are no evolutionary pressures, no selection of advantageous characters occurs and so evolutionary changes simply don't happen.

You too may have 'living fossils' in your home.

February 2019

Weasel words

In 1974 I was the warden of a shingle beach nature reserve in Sussex on which ground-nesting birds, including rare Little Terns depended. Protection for them was mainly aimed at human egg thieves and more natural threats to their breeding success were mostly disregarded. Crows and foxes would have taken a share I'm sure but the only creature that I personally defended the terns from, was a Weasel.

They are the smallest member of a family of mammals grouped together as mustelids and share the genus Mustela with Stoats and Polecats. Otters, American Mink, Badgers and Martens are in different genera, the latter being Martes which is represented in Britain by one species, the Pine Marten - though you won't see one in Nottinghamshire, as they are confined nowadays to Scotland, parts of northern England and a tiny patch of central Wales.

Good evidence has recently been published in British Wildlife that Beech Martens formerly occurred in Britain. They preferred to live in association with people and so were easier to exterminate than the forest-dwelling Pine Marten.

Polecats are the wild version of the domesticated Ferret and seem to be making something of a comeback after a reprieve in their persecution with several verified sightings from Nottinghamshire during a recent national survey.

I'd think twice about grabbing a Polecat or even a Stoat but my encounter with a smaller cousin on the shingle beach resulted in fifteen minutes of me (a younger, fitter person then) pursuing the potential egg thief over the beach with its only hiding places being the occasional Sea Kale plant, until it was eventually more knackered than me and I managed to grab it. Of course I got a painful bite but strategic prising with a pencil got its jaws open and I carried it back into Rye Harbour for release.

When I was a child, wandering the fields around Keyworth, I would frequently come across gamekeepers' gibbets and both Stoats and Weasels were frequent exhibits, hanging in various states of decomposition from a fence or branch. I don't see them today but shoots are very protective of their pheasant releases and some may still treat them as vermin. Most people think Stoats, Weasels and Martens are beautiful, lithe hunters with a place in our countryside and are delighted to see one, even briefly.

If you are wondering how to tell weasels and stoats apart, well: Weasels are weasily identified and a stoat is stoatally different!

January 2019

Systema naturae

Few, if any of us, study Latin nowadays but in the 18th century anything scientific was in that language and so the works of Carl Linnaeus, the Swedish naturalist born in 1707 followed that convention.

Linnaeus was just 23 when he published his first edition of Systema Naturae, in which he began to classify the vast diversity of life in a new way.

I am a fan of Gilbert White who was a contemporary of Linnaeus. His letters, published in 'The Natural History of Selborne' sometimes use the often cumbersome terminology of John Ray, where the Wych Elm is “ulmus folio latissimo scabro” (the elm with very broad, rough leaf) and the Lesser Grey Shrike is “lanius minor cinerescens cum macula in scapulis alba” (lesser ash-coloured butcher-bird with a white spot on the shoulders)!

Linnaeus developed a system over the course of many editions which uses a hierarchy where the plants and the animals form a fundamental tier known as a kingdom and other common denominators are used to sub-divide them further to the ultimate level of genus and species. The names are not always true Latin and use a lot of words of Greek origin as well as English but they have “Latinised” form and endings.

Thus the Wych Elm becomes Ulmus glabra and the Lesser Grey Shrike Lanius minor. All life on Earth now has a name consisting of two words, thus the system is known as the binomial nomenclature.

The system is essentially one of convenience for naturalists and the concept of what constitutes a species can be contentious. With increasing knowledge of the genetic make-up however, comes a better understanding of evolution and the classification fits in nicely with the evolutionary process.

Currently a great deal of research is taking place on the genetic make up of the world's flora and fauna and in many cases this is showing that organisms that appear to be similar are in fact not closely related – examples of convergent evolution – resulting in their re-classification and change of name.

It can be difficult to keep pace with these changes but at least they should stabilise for the long term.