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Starlings January 2020
Recent visitors to the Rec may have noticed a small flock of starlings who have adopted the trees alongside the central path as their daytime roost. Noisy and gregarious, they seem to divide opinion between those of us who like them and others that see them as a nuisance.
Allow me to put in a good word for Sturnus Vulgaris. I think of them as the cheeky chappies of the bird world; they are definitely birds with attitude! They strut their stuff searching for insects in the grass, happily squabbling amongst themselves and with most other birds that cross their path. Sometimes thought of as rather boring in appearance, their glossy black feathers show a stunning iridescent sheen of purples and greens when they catch the light. Also, in the winter, they are handsomely freckled with tiny beige spots. The youngsters are admittedly a dull greyish brown in colour, but soon acquire their adult plumage and need no time whatsoever to develop their bumptious character!
And who can fail to be impressed by one of nature’s greatest spectacles in the form of a starling murmuration. These wonderful displays occur during the autumn and winter months when thousands of starlings congregate to form overnight roosts. Numbers in the UK are swelled by an influx of birds from Europe, who are drawn here to wait out the worst of the continental weather. The reason for such large flocks is thought to be as a protection against predators such as peregrine falcons and the mesmeric twists and turns of the ‘sky dance’, could also have a deterrent effect. A few years back, there were large murmurations that could be seen from the Winnall Moors Industrial Estate just off the M3…some of you may have witnessed them. I remember going to visit one late afternoon in November. I was standing directly beneath the starlings as more and more joined the flock from miles around. It was hypnotic watching them as they seemed to flow through the sky in perfect unison. Then, as if on some unseen signal, they suddenly dropped into the warmth and safety of the reedbeds on the nature reserve. It was a really breathtaking sight!
Sadly, starling numbers are in rapid decline throughout Europe and have fallen by more than 80% in Britain over the last forty years. They are now red listed as a species of High Conservation Concern. It is thought to be due to a loss of suitable nesting sites and a serious depletion in the numbers of soil invertebrates, which they depend on to feed their young.
And if that doesn’t convince you that they’re birds worthy of our attention, perhaps their talent for mimicry will. Starlings are known to copy other birdcalls as well as mechanical sounds. Mozart was certainly impressed! He acquired a starling from a Viennese pet shop that had learned to sing the motif of his latest piano concerto. When it died after 3 years, Mozart held a funeral in his garden, for which, according to Lyanda Haupt (author of Mozart’s Starling), he wrote a ‘whimsical elegy’…..Now, what better endorsement than that!!
Rotting Wood February 2020
Let’s talk rot; well rotting wood to be precise. Wood that is left to rot in situ or turned into log piles and allowed to decay, is ironically, the very stuff of life and one of the most important habitats for biodiversity.
As trees age they begin to decay, often from the inside out. Britain is fortunate in having many ancient trees and often their trunks are completely hollowed out. White rot and red rot fungi attack the heartwood whilst the sapwood remains viable and reducing the weight of a tree in this way, can help to stabilise it and extend it’s life. Other saprotrophic fungi such as the deliciously named jelly rot fungus send out a network of hyphae (think cables) that feed on cellulose and lignin within the wood and convert it to softer material which aids the decomposition process. Add to this thousands of invertebrate species, that as well as calling this environment home, also assist in the breakdown of plant material by burrowing and munching their way through the wood, and in death, there is a veritable flourishing of life. The decomposing detritus is returned to the soil in the form of organic materials to sustain the cycle of life. An astonishing fact gleaned from ‘Trees for Life’ is that the biomass of earthworms in broadleaved forests in Europe is estimated at one tonne per hectare….and that’s an awful lot of earthworms!
So what has this got to do with the Rec, I hear you ask. Some of you may have seen that a tree was recently uprooted and lying on the ground near the tennis courts….fortunately not hurting anyone in the process. It did have some handsome bracket fungus on the trunk, although I’m not sure of the species of tree or fungus. (Please let me know if you do) Anyway this tree is hopefully going to reappear as a couple of log piles on the edge of the garden area. Not your average garden feature and maybe a little untidy looking for some, but please remember that it has the potential to support a wealth of life. Depending on the location, species, stage of decomposition etc, dead and dying wood provides a habitat for 1,800 invertebrate species. They in turn encourage predators such as frogs, toads, birds and hedgehogs to feed and sometimes shelter in the log pile. That’s before you even count the fungi, mosses, liverworts and lichens that can also occur.
Of particular relevance to the Rec is the fact that we host stag beetles; a magnificent creature that is listed as a priority species under the Wildlife and Countryside Act. We know this because we found a larva when we were digging out the pollinator patch last year. The larvae of the stag beetle are entirely dependent on rotting wood which they feed on for between 4 and 7 years before finally emerging as an adult. We assume the female was attracted to laying her eggs there because of the rotting bark mulch. We are privileged to have these insects that now only occur in the south and east of the country and have been in decline probably due to loss of the very thing they are dependent on, which is rotting wood. We somehow need to shake the habit of being far too tidy!
So when you see the log piles in the Rec, please don’t think of them as a scruffy eyesore, they are in fact, a vital, life giving resource.
Birch Trees March 2020
In these troubled times, I think we can always find comfort and pleasure in Nature. As we undergo the worst crisis that most of us can remember, Nature continues on her course. I’m writing this on 20th March, which is the Vernal Equinox; the astronomical start of Spring when the hours of darkness are equal to those of daylight. Everywhere in the Rec, there are signs of life renewing itself, from the buds on the trees to emerging bumblebees and the gathering chorus of birdsong.
The tree associated with renewal and purification in Celtic mythology was the Silver Birch (Betula pendula) and bundles of birch twigs were used to drive out the spirits of the old year. The belief persisted through time and miscreants were ‘birched’ supposedly to expel evil spirits, which was also the reason Birch twigs were used in the ancient custom of Beating the Bounds.
There are 3 silver birches in the Rec and they are one of our most recognizable of our native trees. Having not yet come into leaf, their two most characteristic features are very apparent.
The first, and most obvious is their silver- white trunk with its scattered black fissures; it sheds layers of bark that resemble tissue paper. The name itself is thought to have derived from the Sanskrit word bhurga meaning ‘a tree whose bark is used to write on’. As the tree ages, the trunk, becomes more rugged with diamond shape crevices and a dark base.
The other feature is its graceful, pendulous habit as reflected in its Latin name, pendula. Its clusters of reddish coloured twigs are elegantly draped and lift in the wind, looking like fronds of seaweed bobbing on the water’s surface. Seen in winter light, groups of silver birches are very distinctive with their white trunk and the purplish red haze of their canopy.
The male catkins form in autumn with two or three at the tip of the twigs, and their reddish brown scales add to the overall tinge of the trees’ winter garb. They develop fully by April or May to coincide with the growth of the more upright female catkins. Both male and female catkins occur on the same tree, and pollination and subsequent seed dispersal relies on the wind.
The leaves are triangular in shape, irregularly toothed and appear towards the end of April. They are borne on slender stalks which allow them to twist and flutter in the breeze adding to the tree’s slightly ethereal quality. In autumn the leaves turn to bright yellow.
Silver birch provides food and habitat for about 300 species of insect, including the caterpillars of many moths. It is also associated with specific fungi such as birch brittlegill, birch milk cap and fly algaric.
This familiar tree has been celebrated in a series of beautiful paintings by the artist Gustav Klimt and justly deserves the epithet given by the Romantic poet, Samuel Taylor Coleridge; “the most beautiful of forest trees, the Lady of the Woods”
Additional notes for March 2020:
In the above posting, I talked about the Silver Birch trees at the Rec, but the observant amongst you may have noticed another, but slightly different Birch, at the corner of the Grosvenor Road entrance. Its bark is startlingly white and difficult to miss especially at this time of year.
This tree is Betula Utilis,, a rather prosaic epithet for a very beautiful tree, which is naturally found growing on the high slopes of the Himalayas. Unlike our native Silver birch, it has a more upright habit and open pyramidal shape. However, it does resemble it, in that the male and female catkins appear on the same tree. The male catkins are formed in the autumn and hang in 3s and 4s from the end of the twigs. They are reddish brown and described as looking like lambs’ tails, but in my rather fanciful mind, I see any number of birds’ feet hanging out to dry!! The catkins will soon begin to elongate and open, and the upright female catkins will develop making it easier for wind pollination to take place, before the tree is in full leaf. The leaves themselves are dark green, toothed and slightly lighter on the underside, causing them to shimmer in the breeze. Like the Silver Birch they turn a glorious yellow in the autumn.
The Sanskrit word for the tree is bhurja which is thought to be the origin of the more common name of birch, in this case, the Western Himalayan Birch. ‘Utilis’ is the Latin name of this species, and refers to the number of uses that various parts of the tree are put to, in its native range. It became known to the Western world in the early 1800s, when it was discovered in Nepal, and was given its current nomenclature in 1841. It was then adopted as an ornamental tree in parks and gardens, mainly for it’s brilliant white bark. This bark peels away in horizontal layers, resembling paper and hinting at the reddish brown heartwood underneath.
The bark was widely used as paper up until the 16th century and a number of ancient Sanskrit manuscripts written on birch bark have survived, including examples in the Bodleian and British libraries. The tradition of writing mantras on bark still exists, and they are carried as amulets around the neck or arm in order to provide protection for the wearer. More practical uses for the bark include packaging and roofing, while the wood has been used locally for building houses, bridges and other infrastructure. Various parts of the tree are also used in traditional medicines.
Sadly the tree is disappearing from many parts of its range and in places like Kashmir is considered to be ‘Critically Endangered’. This is partly due to the fact that the people living in the high altitude of the Himalayas rely heavily on the tree for firewood and fodder which has led to overharvesting. But other factors such as pollution and climate change also play a part.
Let’s hope that this wonderful tree does have a future in its rightful home, and next time you’re passing, please pause to admire the beautiful stranger living amongst us.
The garden in lockdown! April 2020
As we enter the 4th week of the lockdown, life seems to be adjusting to a new normality which is uncomfortably different, especially for people like me who’ve been advised to stay at home for 12 weeks ….only 8 more to go…… maybe?!
Now, nearly all my experience of ‘real life’ is mediated through the radio and TV, and the Rec is sadly out of bounds. But I am lucky enough to have garden, and so I’m able to watch Spring unfolding as Nature puts on her very best flowering, buzzing, burgeoning display.
Amongst the creatures I’ve noticed flying around in the garden is one of the earliest bee species to emerge, the wonderfully named Hairy-Footed Flower Bee (Anthophora plumipes). It looks like a small bumblebee and sounds like a bumblebee, but its swift, darting flight and ability to hover, makes it more redolent of a hoverfly. It is a bee, but not of the ‘bumbling’ variety, it’s a type of solitary bee. Solitary bees don’t nest communally like the bumblebees and honey bees; each female creates and provisions her own nest in underground burrows or other cracks and crevices especially in buildings.
The Hairy-Footed flower bee has a preference for mortar, exposed banks or soft cliff faces, but they will occasionally nest in the ground in compact clay soils.
This species exhibits sexual dimorphism, meaning that the male and female look quite different. The male tends to emerge a couple of weeks before the female, usually at the beginning of March. He is tawny brown in colour with a distinguishing cream coloured patch on his lower face. If he stays still for long enough, you might see the long plume of hairs on the lower part of his middle legs, which give rise to the species’ name. These hairs are thought to play a part in the mating process. The male bees are very territorial and will protect their patch by chasing off intruders. They have been observed flying at speed to head butt any unfortunate insect that happens to stray onto their home ground!! His role is to solely to mate with the female, after which he dies; a short, but happy, if somewhat aggressive, existence! The female is black and easily recognised by the orange hairs on her back legs that make up the pollen basket. Both are about 14mm in length and have a single flight period from March to May.
The Hairy-Footed Flower Bee is a long tongued species and often approaches flowers with its tongue extended and on display. Because of its long
reach it favours tubular flowers such as lungwort, dead nettle and comfrey.
As with other solitary bees, once she’s mated, our Hairy-Footed bee will lay the eggs in her chosen nest site. Each egg will be sealed in an individual chamber with a supply of nectar and pollen for the larvae when they emerge. The larvae pupate and for many solitary bee species, they overwinter in this state. However the adult of the Hairy-Footed bee emerges in the autumn and spends up to six months sealed in its chamber until it takes flight the following spring, to start the cycle all over again…..now that’s what you call self isolation!!
For some superb photographs, please check out www.flickr.com
The Garden in Lockdown Part 2 May 2020
I was wondering what to write about this month. Swifts or cow parsley perhaps? Then we went for a short walk in the Test Valley Nature Reserve. The air was full of delicate white particles floating effortlessly on the breeze; it was like walking through a gentle flurry of snow. In places, the ground looked like it was covered in cotton wool. These were the thousands of seeds of the crack willow dispersing on the wind and falling wherever the air currents took them. It made me think about how exquisitely seeds are designed to serve their purpose.
Nature has engineered the perfect solution for sedentary plants to spread and in doing so has created objects of great beauty.
Wind dispersal is one of the techniques that plants employ. This requires some of the most delicate of seeds that either float using their own miniature ‘parachutes’, or spiral on papery wings. The latter is represented by a number of tree species in the UK such as field maple, ash, sycamore and hornbeam.
But for me, one of the most beautiful of wind- blown seed heads occurs on one of our commonest plants. It is the delicate, ephemeral seed head of the dandelion. I hear gardeners groan as I write this, but its testament to their superlative design that their progeny sprout all over our gardens. An article in Nature magazine (Oct 2018) reports a study that reveals ‘the extraordinary flight of the dandelion’ and the previously unknown biodynamics. As wonderful as that is, it’s the great beauty of the seed head that rewards our attention. There are upwards of 100 seeds that make up each head, and every seed is attached, via a stalk to a silvery, filamentous ‘parachute’; together they form the intricate, globe, commonly known as a dandelion ‘clock’. And generations of children have attempted to tell the time by blowing on these ‘clocks’ and watching the seeds as they disperse and float, seemingly weightless in the air…I’m sure, to the further delight of gardeners!
But sadly, both dandelion and willow are amongst the ’lost’ words that have been removed from the Children’s Oxford Dictionary. How sad it would be if future generations grew up failing to notice these lovely plants, that although common, hold a world of wonders.
Dandelion June 2020
Last time after seeing what I’d written about dandelion seedheads, a friend drew my attention to the logo of the French encyclopaedia and dictionary, Le Petit Larousse. It features a young woman blowing the seeds from a dandelion ‘clock’ with the motto “Je seme a tout vent’ (I sow to all the winds) and I thought how the dispersal of these seeds is a beautiful metaphor for spreading knowledge The publication first appeared in 1905, and the logo has remained basically the same with the design changing only to reflect contemporary artistic styles.
This then brought us on to the derivation of the name, dandelion, and another French connection. It is a corruption of the French dent de lion, and so named because the jagged edges of the leaves were thought to resemble a lion’s teeth. But in France, she told me, the dandelion is commonly known as Pissenlit, which probably needs no translation! But this accords very well with what I was told as a child, which was “Don’t pick dandelions or you’ll wet the bed”. I understood that this belief resulted from the fact that the dandelion exudes a milky sap from the stem when it’s picked, although I’ve since discovered that it has been traditionally held to have diurectic properties if consumed. In fact every part of the plant is edible and rich in vitamins and minerals. The leaves and petals can be eaten raw or cooked and used to make infusions and wine, whist the root can be roasted and ground to make a coffee substitute. The latter was popular during World War II when coffee was scarce and rationed. I remember helping to make dandelion wine once, having been given strict instructions to carefully remove the petals from each flower head. I had to work my way through a whole bucketful of them as they were rapidly folding themselves up, as if to protect the precious petals from my unwelcome plunder!
Still, we’ve come to know this attractive, useful plant as one of that most maligned group we call ‘weeds’. It is far too successful for our liking with its superb ability to seed and its really deep taproot that makes it difficult to eradicate. But if we set aside our learned prejudices, and look at the dandelion with fresh eyes, we can perhaps see them as the poet John Clare did, as ‘fallen stars in a green sea of grass’ The flowers which are made up of around 200 individual florets are really quite stunning and when growing with others produce a blaze of golden colour, seldom matched. They are a really important source of nectar for a whole host of pollinators early in the year when few other plants are flowering. And the ethereal beauty of the seedhead with its promise of wish fulfilment to those who blow and scatter the seeds, has inspired poets, painters and designers. One famous example is the ubiquitous Sanderson Dandelion Clock range of fabrics and wallpaper.
The Dandelion even has its very own Appreciation Society. And in the Language of Flowers, the Dandelion stands for faithfulness and happiness, which is not a bad recommendation for a beautiful weed that changes ‘from suns into moons’ (Nabokov).
Bird Song July 2020
The old saying goes that ‘One swallow doesn’t make a summer’, but for me and many others living in an urban environment, one swift definitely does! I look for their return every year around the end of April, beginning of May, and hearing their shrieking calls as they pass overhead, makes me think that some things, at least, are still right with the world. (See:Ted Hughes, ‘Swifts’. An evocative poem).
The Latin name for the swift, Apus Apus comes originally from ancient Greek meaning footless, because In the Classical world they were thought to be swallows without feet. Their legs are indeed very short, but being supremely ariel birds they have no need to walk or hop on the ground. They also have weak feet, although the 4 toes are arranged in such a way that they can cling on to vertical surfaces such as brick walls. But their element is the air and with long scythe like wings, they are masters of it. They slice through the skies reaching speeds of up to 70 mph as they soar, dip and twist as if about some urgent business that just won’t wait. They spend most of their lives on the wing, feeding, sleeping and mating, and land only to nest.
They used to nest in the eaves of old houses, under broken tiles and in other cracks and crevices. But since we’ve become more tidy and keen to insulate our properties, a lot of their traditional nest sites have been lost. I remember watching swifts nesting under the gable of the house opposite many years ago and marvelling at how they would suddenly drop out of the nest and very quickly gain height and speed. My husband was brought up in a thatched property in Devon and every year the swifts would return to nest in the thatch. Unfortunately because it was fairly low hanging, the cat got wise to the fact that the swifts trajectory was initially downwards, and would sit patiently waiting to knock them to the ground as they emerged. It’s then that the birds’ very long wings and very short legs are a huge disadvantage, because it’s extremely difficult for them to get airborne again. Thankfully, most were rescued and relaunched!
It’s amazing to think that these birds travel such a vast distance, from Central Africa, for such a brief stay with us. They have usually left by the middle of August at the very latest. Our very own Hampshire naturalist, Gilbert White was one of the first people to properly study this “amusive bird”, as he described it. He noticed that the swifts had disappeared by August and weren’t seen again until the following April. He speculated as to whether it was really possible for such small birds to migrate long distances and posited the theory that they might hibernate over winter or as he put it, ”retire to rest for a season”. But he was the first person to notice and record the fact that swifts mate on the wing. However, he could never have imagined what recent research has shown about their ability to sleep on the wing. They fly to about 10,000’, then shut down half their brain and by continually correcting for wind drift, wake up in exactly the same position in which they fell asleep. How impressive is that!
If you feel able to help these truly amazing birds, whose numbers are unfortunately in decline, please consider having nest boxes fitted on your property. The Hampshire Swift Project will supply and fit a box for £30.00.
They are calling it insectageddon; the rapid and dramatic decline in insect populations throughout the world. Insects make up over half the species on earth and we are utterly dependent on them for our survival. They pollinate our crops, recycle organic materials and are the basis of the entire food chain. And yet, according to Buglife, the rate of loss is 8 times higher than that of birds and mammals. We need to act quickly to reduce our dependency on harmful chemicals and leave more areas in our landscape to go ‘au naturel’.
The gardening group at Friends of Portswood Rec (FOPR) decided we would make our own very small contribution by creating a bed for daytime pollinators such as bees and butterflies. The circular bed had previously been planted up with moths in mind (also very good pollinators), but unfortunately because of council cutbacks had become rather neglected. So in November 2018, with some help from the University gardening team, the group set out to clear the bed. We relocated a number of the surviving shrubs and declared war on the weeds, especially the brambles and thistles. And yes, both are good for pollinators but far too thuggish for a semi formal flowerbed. We eschewed the use of chemicals, which would have been completely at odds with what we were trying to achieve. And so we dug, and dug, and then dug some more! It seemed like every time we turned our backs for a short time, another bramble or thistle had popped its head above the surface!!
But with a supreme effort on the part of the gardeners, the bed was ready for planting by spring 2019. We sourced most of the plants from Mayfield Nurseries, who kindly supplied them at cost price. The bed was designed allowing for its hot, sunny location, with plants that are mostly designated by the Royal Horticultural Society (RHS) as ‘Perfect for Pollinators’* and with a view to providing a long flowering season from spring through to autumn. We were pleased that many of the plants actually flowered in their first season and looked forward to even better results in 2020.
We had just started up again in March of this year when coronavirus and the complete lockdown, stopped us in our tracks. Ever the pessimist, I feared the worst, especially given the long, dry spell when we weren’t able to do anything. I fully expected to return to find that most of what we’d planted had curled up and expired for want of water, and that the weeds had reasserted themselves.
I was pleasantly surprised. Yes, there were a few things that hadn’t survived, amongst them some that I would have least expected, such as the rosemary and one or two of the lavenders. But the Pollinator Patch, as we’ve come to know it, was comparatively weed free and in rude health. I hope all of you’ll agree that it is looking rather splendid and is a great testament to all the volunteer gardeners who have put in so much time and effort………….and it would appear that the bees and butterflies are pretty grateful too!!
We can all do our little bit to help the insects on our home patch, be it in a garden, planter or pot. Please see below for some tips and
*A Few thoughts about Gardening for the Planet:
1. To plant Native or Not? The jury seems to be out on this one. There’s no doubt that native insects and plants have evolved over millennia to their mutual benefit, but many insects seem to have pretty catholic tastes. The RHS have a Perfect for Pollinators designation, which includes many non native plants.
BUT BEWARE! Dave Goulson (the bumblebee guy) got a student of his to analyse a number of plants purchased at well known chain stores and marked as being Perfect for Pollinators* They found that 76% contained at least one insecticide and 28% had two or more. It seems that there’s a heavy reliance on pesticides in nurseries where plants are raised en masse and expected to look perfect for the supermarkets and garden centres. The RHS’s response has been to change the designation to Plants for Pollinators…not quite the robust action needed I feel!
2. Avoid all chemicals. As Joni Mitchell famously said (in the song Big Yellow Taxi), “Give me spots on my apples, but leave me the birds and the bees’ We have to accept a bit of imperfection here and there and generally speaking nature will find a balance. Even the wee beasties loathed by gardeners such as aphids have lots of natural predators, including other insects like much loved ladybirds. Chemicals can persist and build up in the environment, passing from prey to predator, and going all the way through the food chain. Some of us remember how DDT once pushed peregrine falcons to the edge of extinction...not that you’re likely to get many of those in your garden!!
3. Leave a few wild patches if you have the space. They’ll be beneficial for insects, small mammals and birds. As a society, I think we are rather too fond of tidiness and order, in our parks, on our road verges and in our gardens. This is often to the detriment of wildlife and perhaps we’d do well to embrace the slightly scruffy now and then. As Gerald Manley Hopkins put it in his poem Inversnaid: ‘Let them be left, O let them be left….long live the weeds and the wilderness yet’. Or you might prefer Bill Oddie’s rather more prosaic “Say yes to mess!”…..at least a little!
4. Avoid peat based compost. The peat bogs are incredibly important ecosystems that have taken thousands of years to form and are the largest natural terrestrial carbon store. They filter and purify water, mitigate flood risk and support a precious wildlife community. In the UK and Ireland we have peatlands of international importance but many are in a badly degraded state and others (especially in Ireland) have been disappearing at an alarming rate, in large part because of demand from the horticultural sector. Most compost on sale contains between 70 and 100% peat, and much as we love our gardens they’re definitely not worth the destruction of such important and fragile ecosystems, especially as there are now alternatives.
Some organisations campaigning for insect conservation are:
Buglife, The Bumblebee Conservation Trust, The Butterfly Conservation Trust and The British Dragonfly Society.
From now until 9th August the Butterfly Conservation Trust are asking people to participate in the Big Butterfly Count. Please check out their website to find out how you can help.
At Portswood Rec we are lucky enough to regularly have bats hunting over the garden and among the trees. As dusk starts to move to earlier times, we are more likely to catch a glimpse of these amazing nocturnal creatures. There are 18 species of bat found in the UK.
The common pipistrelle is the most numerous, with a population of 2.4 million, while the least common is the greater mouse eared bat, with just one individual currently hibernating in the UK.
During the day, bats roost in a variety of different places, including crevices in buildings, holes in trees, and caves. Then as the day draws to a close, they leave the roost to hunt. The first to emerge is the noctule bat, the biggest of the UK bat species, which can sometimes start flying before the sun has set. Around 20 minutes after sunset, the common pipistrelle takes flight, ready to begin its daily meal of up to 3000 insects, and about 10 minutes later the Daubenton’s bat starts flying low over bodies of water to fish insects from the surface. The diet of bats is made up of all kinds of flying invertebrates, including midges, flies, moths, and beetles.
The primary method bats use for detecting and closing in on their prey is echolocation. The bat emits a short ultrasonic call, and listens for its echo from any unfortunate passing insects. The frequency of this call depends on the species of bat, and ranges from 20-25 kHz for the noctule bat, to 108 kHz for the lesser horseshoe bat. In fact, the frequency of the call can help to identify species, and it is the easiest way to distinguish between the common and soprano pipistrelles, only recognised as different species in the 1990s. Some bat calls are audible to children and some adults, but a bat detector can be used to convert the ultrasonic frequencies into lower pitched sounds, or into a visual format which makes certain characteristics of the calls more apparent. For instance, as a bat closes in on its prey, its calls become more rapid and it also drops the pitch of the sound, giving the call a “chirped” quality. Interestingly, this technique has been developed independently by humans as well – for use in car proximity sensors!
Because bats need to detect the echo from tiny insects some distance away, their calls have to be extremely loud. Their ears have special muscles that temporarily dislocate the ear bones while they call, to avoid deafening themselves, and then relocate them within a few milliseconds in time to hear the returning echo. The loud volume also means that echolocation uses up a lot of energy for the bat, as does flying, and they therefore want to know if it is worth leaving the roost on a particular night to hunt. They are able to detect lower barometric pressures, which indicate rain, and prefer to hunt in these conditions as they provide the most insects – although they avoid heavy rain, which impedes their echolocation.
Unfortunately, bats have seen a large decrease in numbers in the last few decades, partly driven by losses in suitable roosting sites like old buildings, woodland, and ancient trees. However, there are many things that can be done in our own gardens and parks to attract and help bats. Planting trees, hedges and shrubs, leaving old trees in place where possible, and putting up bat boxes in sunny locations can all provide places to roost. Attracting insects for bats to feed on is also important, by having ponds and log piles, avoiding pesticides, and planting flowers to attract insects. Particularly good for this in the late summer and autumn are michaelmas daisies and single flowering dahlias - and outside the flowerbed, ivy is also excellent for insects. For bats, evening-scented flowers such as honeysuckle and evening primrose are also especially important. Additionally, the Bat Conservation Trust is running a sunrise / sunset survey until the end of September, for people across the country to record sightings of bats in their area - with identification of the specific species welcome but not required!
Interesting and useful links:
A video of bats at Portswood Rec, with audio of their calls from a home-made bat detector:
Some wonderful videos of bats and other wildlife, taken around Southampton by Ian Baker:
Information on building your own bat detector from Bertrik Sikken; the sound in the video above is from the Enhanced TCA440 detector from this page:
The Hampshire Bat Group website:
The Bat Conservation Trust website:
And their page about the sunrise/sunset survey:
Few things remind us of autumn more than conkers; the seeds of the magnificent horse chestnut tree. This tree that frequently adorns our parks, streets and gardens is actually quite a ‘johnny come lately” to this country. It originates from the Balkans and was only introduced here at the end of the 16th century.
It has a beautiful spreading crown and as well as its autumn crop of conkers, has the most attractive flowers which form distinctive white spires in the spring . Their appearance has led to the colloquial name of ‘candles’. This flowering is celebrated every May at Bushy Park, London, where a mile long Chestnut Avenue was planted in 1699 by none other than Sir Christopher Wren. ‘Chestnut Sunday’ as its known, was abandoned at the start of World War II, but re-established in 1977 and every year people gather to parade, picnic and appreciate the trees at their very best. As well as looking beautiful, the flowers are a valuable source of pollen and nectar for insects, and especially bees.
But it’s the conkers that the trees are most known for amongst schoolchildren. They are the seeds for the next generation of trees and their dispersal largely depends on gravity. They fall from a great height, which breaks the green, prickly outer casing and the conkers bounce or roll to their final location, where they will hopefully germinate. They’re unable to depend on animals to help with dispersal, because conkers are poisonous to all but deer and wild boar. Although surprisingly, in the tree’s native home, horses have traditionally been treated for various ailments using them, which is thought to be one explanation for the name. Another theory is that it may derive from the horseshoe shaped scar that is left by the leafstalk after the leaf has fallen.
But many of the conkers, which have a variety of vernacular names such as Obblyonkers or Cheggies, never get to germinate. These lovely shiny brown seeds are gathered up by children, hardened off, threaded on a piece of string and used to bash against one another (ideally reducing one to smithereens) in the eponymous game of conkers. The occurrence of the game was first recorded on the Isle of Wight in 1848 and the Conkers World Championship is now held annually at Southwick in Northamptonshire. The idea was conceived in Ashton in 1965, but had to be relocated because it grew so popular that they needed a larger site! On a more serious note, the British Government actually offered a monetary reward for the collection of conkers during both World Wars. Being a source of acetone, they were used to make cordite for manufacturing armaments.
Unfortunately, as with so many of our trees, the Horse Chestnut is susceptible to certain diseases such as bleeding canker, which can kill the tree, and from attack by the caterpillar of the horse chestnut leaf miner moth. The latter can weaken the tree and make it more susceptible to other stresses. On the positive side, the caterpillars are a valuable source of protein for birds during the nesting season.
So next time you visit the Rec be sure to check out the Horse Chestnut trees; there are still conkers to be had and yours could be a champion!
At this time of year as colour is starting to fade from the garden, it is time for the vibrant leaves of the trees at Portswood Rec to take the stage in the autumn sunlight. As the days get shorter, the trees respond by starting the process of abscission, or leaf drop, in order to conserve water and prevent damage over the winter months. The first stage of this process is to extract key nutrients from the leaves. Chlorophyll is broken down and resorbed into the tree, to be stored in its branches, trunk and roots ready to produce new leaves in the spring. With the green chlorophyll removed, the other pigments in the leaves start to show through. The yellows and oranges are the colours of the carotenoids that are present in the leaves all year round, and are the same pigments that give carrots, pumpkins and tomatoes their colours. Reds and purples, meanwhile, are produced by anthocyanins, also responsible for the colours of blackberries, plums and cranberries. These pigments are produced in the leaf in late summer, as the chlorophyll starts to be broken down.
Once the majority of the nutrients from the leaves have been resorbed, a layer of protective, waterproof cork cells is formed, and the leaf is detached at a point known as the abscission zone. Here, there are two layers of specialised cells: one layer with weak cell walls, and a second layer that expands in autumn to break the two layers apart and cause the leaf to fall.
A single tree can have tens of thousands of leaves, all falling to the ground in the space of a few weeks in autumn. In a deciduous forest, this can mean that every 10 square metres of forest floor is newly covered by 3kg of leaves. In this same area, there can be 1kg of earthworms, 2.7kg of fungi, and 1.7kg of bacteria, all feeding on the leaves, breaking them down, and providing nutrients back to the trees.
First, creatures like worms, ants and woodlice draw the leaf litter down into the soil. As they do so they also create structure in the soil, allowing water and air into it. The oxygen in this air is needed by many of the bacteria in the soil, like the actinobacteria that break down cellulose and lignin in the fallen leaves. These produce the pleasant, earthy smell of good soil. Without sufficient oxygen, anaerobic bacteria take over the decomposition and produce an unpleasant rotting smell instead. Alongside the bacteria, a succession of fungi also breaks down different parts of the leaves: first the sugars and starches, and then the cellulose and lignin in the cell walls. Once the leaves have started to decompose, they form the diet of many creatures in the soil, including nematodes, soil mites and insect larvae, as well as worms, millipedes, slugs and snails. These all break down the leaves further and release their nutrients in a form that can be absorbed again by the tree and used to produce fresh new growth.
Not only does all the life in the soil perform this constant recycling process, there are also huge branching networks of mycorrhizal fungi and actinobacteria that live symbiotically with the trees. They take carbohydrates from the roots of trees, and in turn provide the plant with accessible nitrogen. Filaments of these fungi can extend well beyond the roots of the tree, increasing its feeding range and connecting it to other trees nearby, even providing saplings with nutrients from surrounding trees.
For us, the autumn colours of leaves can seem like a final great flourish before winter. But this is just the beginning of the story happening in the soil, where this complex cycle connects the tree to countless other organisms, and provides nourishment for the bright, fresh growth of the spring.
November and time to tidy up the garden ready for the winter? Well, that certainly used to be the practice. Everything cut back, swept up and neatly tidied away, in preparation for the following year. But for the wildlife in our gardens, being ultra tidy is about the worst possible thing, depriving them of safe spaces in which see out the winter months.
The fact is that if we want the butterflies, birds and hedgehogs to share our space, we need to take care of them all year round. And in order to survive the winter, wildlife relies on us having a more casual, laid back approach to gardening. Hollow plant stems, fallen leaves, long grass, log piles and other organic debris provide ideal conditions for a variety of overwintering creatures. Hedgehogs use fallen leaves to create a warm nest in which to hibernate and log piles make ideal hiburnacula for frogs and newts.
But these animals and our garden birds are all reliant on a healthy supply of insects, and that’s why we’re adopting a relaxed approach to managing the Pollinator Patch (central bed) in the Rec. The reason that we haven’t trimmed everything back and tidied up, has nothing to do with Covid, or inertia on our part, it’s intentional and we hope, insect friendly!
There are a few insects that are active throughout winter, but most going into a type of hibernation known as diapause, which is a period of suspended development. This happens at different stages of the life cycle according to the species. Some overwinter as eggs, others as pupae and some as adults, but all require somewhere safe and secure until the warmer weather and lengthening daylight indicate it’s time to emerge. It’s our intention, that by leaving this year’s perennials to die back naturally, we’ll provide winter quarters for some of our beleaguered insect friends. Then we’ll set to and tidy up in the spring, by which time they will hopefully have dispersed.
Insects really do need as much help as we can give them. The charity Buglife, the only European organisation devoted to the conservation of all invertebrates, highlights the catastrophic worldwide decline in our insect populations. Those of us who are old enough will realise that loss by reference to the ‘splatometer test’.
We remember the days when a summer trip out in the car resulted in a windscreen almost obscured by the number of insects that were unfortunately killed. And various studies using the splatter rate have confirmed what we instinctively knew, namely that there are far fewer insects around. Buglife is running a campaign called No Insectinction in an attempt to halt the decline which, as they say, is essential for the future of our planet.
So we can all play our part. Store away those secateurs, put your feet up and brew a cuppa. Then delight in the sculptural beauty of the rime on the spent seed-heads and get that inner glow of satisfaction knowing that you’re making a contribution towards securing the future of our planet. Not a bad afternoon’s work!!
It’s at this time of year, when other plants have died back, that our native evergreen species take centre stage. Holly, yew, mistletoe and ivy brighten our countryside, and feature prominently in folklore and midwinter celebrations.
But it is the ubiquitous Common Ivy that probably divides opinion most of all. This hardy creeper is the bane of some gardeners’ lives, being vigorous and tenacious. However it’s not, as often assumed, parasitic like mistletoe. Its ariel roots are used to cling to the supporting surface, but it obtains all its nutrients and water from a separate root system in the soil. So ivy doesn’t kill trees by parasitizing them, as popular belief would suggest, although it may eventually bring down old or diseased ones, owing to its size and weight; a mature ivy can reach up to 30m in height, at which point it may also crowd out the light.
This all too common plant can be seen growing around the perimeter of The Rec, and its presence is something that we rather take for granted. But it’s a species with huge wildlife value. Ivy has the unusual characteristic of taking two different forms, the juvenile and mature. The plant in its early growth prefers shady locations and produces leaves with either 3, or more usually 5, lobes. It will spread along the ground until it finds a suitable surface to climb. Rootlets then form as young growth touches the support, and the tip of the rootlet forms an adhesive pad. It’s only when the ivy reaches a certain height, age, or possibly light level, that the leaves begin to become more heart shaped. At this point the growth becomes self- supporting and begins to produce flowers and berries. The flowers are a citrus green and appear in small dome shaped clusters known as umbels. They are rich in nectar and as they ripen into berries, they turn from brown through to a dull, inky black. Each berry contains up to 5 seeds.
In terms of its wildlife value, ivy is absolutely up there with the best!
According to the Woodland Trust, it supports at least 50 species. Ivy’s late flowering from September to November provides an invaluable source of nectar for all sorts of insects when little else is available. Wasps, hoverflies, bees and some butterflies all benefit. When you see flowering ivy next autumn, pause a while and you’ll soon discover that it’s humming with life. The berries ripen from November through to January and their high fat content makes them appealing to birds such as blackbirds, thrushes and wood pigeons. I remember some time ago, watching a number of ungainly wood pigeons precariously perched on an ivy bush as they stripped it of its berries. Ivy is also used by the Holly Blue butterfly on which to lays its eggs. Its caterpillars feed on the flower buds, as do those of sixteen species of moth. And as if that isn’t enough, the plant provides year round cover for all sorts of creatures, in which they can nest, roost and hibernate.
Ivy can also benefit the environment in other ways. A study done by English Heritage and Oxford University showed that walls covered in ivy kept that part of the building 15% warmer in winter and 36% cooler in summer than the rest of the building. It also helped to protect walls from frost, salt and pollution.
So next time you’re out and about, take a closer look at this wonder of nature.