Talk notes: Managing the NT hillforts and chalk grasslands for both archaeology and nature conservation
Clive Whitbourn, National Trust Ranger, started his talk with a focus on Hambledon Hill, the 47 hectare hillfort which came to the National Trust in 2014. It is a Site of Special Scientific Interest and a photo from 1940 showed how bare the hillfort was 80 years ago. Now the hillfort is managed lightly, with scrub kept low and any erosion kept at bay with terrace reshaping to preserve the profile of the ramparts.
Clive showed us the methods they use with wooden frameworks buried deep to support hessian bags full of chalk, which bulk out any damaged areas, with turf from the ditch placed on top. The chalkland grasses grow through and thrive. He mentioned that the south and south-west ramparts of Hambledon Hill are best for butterflies.
Cattle scraping for minerals – they can go on binges to self-medicate - and visitors wearing down paths, all play their part in erosion. Roboflail, a mechanical AI cutter, is being used on some of the NT sites to great effect to keep the scrub low and save the man hours for other tasks. The NT relies on volunteer help on many of their conservation projects.
Hod Hill is Dorset’s largest Iron Age hillfort and is unusual because it has a Roman fort nestled within, built at a time when the invaders needed to defend their capture of this Durotriges stronghold. Clive showed us how the framework and hessian bag method was also used to repair a bridleway here.
In terms of nature conservation, Texel sheep are good grazers and White Park cattle are brilliant for rough pastures. Yellow Rattle, which suppresses coarse grass growth, is doing well at Winn Green and there are plans this year to brush-harvest the seed from there and broadcast it to the newly purchased Clubmen’s Down, a 30 acre piece of arable.
Across Clive’s patch and the various Downs and hillforts, uncommon species are being noted: Bee and the Great Butterfly orchids, and the unusual Autumn Lady’s Tresses; Waxcap fungi; Marsh, Silver-spotted and Danville Fritillaries, Grizzled Skippers, Small Blue and Adonis Blue butterflies; Great Green Bush-crickets and Glow worms.
Clive’s talk gave us plenty of inspiration for visiting these places, particularly in the spring and summer!
A cutting of Erigeron daisies taken from my courtyard released a curious flatworm later in the day at its new home. Thankfully it was spotted and isolated, while the two thin red stripes and features were pored over. The RHS later had to come to our rescue with the identification (thank you, Lynne, for your help with this) and this is what they said. It's worth knowing about in case other people make similar discoveries, because these flatworms should be destroyed.
"I think that it is likely that the flatworm you have found is Kontikia ventrolineata. This is a non-native flatworm, with origins probably to Australia and/or New Zealand, whilst some records indicate also the Indo-Pacific region. It is a small flatworm with a dark coloured body. This flatworm species is thought to have been introduced in 1840 and has several UK records. It can feed on small invertebrates that it can catch, including small snails but it also appears to be a scavenger.
Once it has arrived in a garden there is really nothing effective that can be done to reduce their numbers. Destroying any that you find hiding underneath pots or stones will remove a few, but this is likely to be only a small proportion of the population in your garden. There are no pesticides available that will control flatworms.
Kontikia ventrolineata, is listed under Schedule 9 to the Wildlife and Countryside Act 1981 with respect to England and Wales and it is an offence to release it or allow its escape to the wild. You should endeavour to avoid spreading the flatworm to new areas that are as yet free of flatworms. They spread to new areas through the movement of growing plants, compost or soil, so you should be careful about giving growing plants to other gardeners.
More information about flatworms can be found at https://www.rhs.org.uk/advice/profile?PID=975 "
Rebecca Twigg started her talk last week by stressing the relative unimportance of honey bees compared with wild pollinators such as solitary bees, bumblebees, moths, butterflies, hoverflies and beetles. She gave several examples of solitary bee species that are commonly found in gardens such as the Ashy and Tawny mining bees, as well as the recently arrived Ivy bees, and explained interesting details about their lifecycles and habitat requirements. Later, she gave us examples of the best garden flowers for pollinators, natives as well as exotics.
She stressed the importance of having flowers blooming all year round, with Heathers from late winter, Lungwort in early spring and continuing right through to early winter with Mahonia, for example. Rebecca explained how she restocks her garden by swapping plants, growing from cuttings and collecting seeds rather than buying from
Rebecca pointed out how planting in drifts is so important, so the bees don’t have to waste energy flying between individual flowers, making sure there’s a variety of flower types, e.g., Foxgloves for long-tongued bumblebees and daisies for short-tongued hover-flies.
Rebecca then spoke about creating different habitats in gardens, to provide for the diverse requirements of different pollinators. Drilling holes between 5 and 8mm and pencil length into wooden panels, logs or posts placed in warm, sunny situations can provide valuable nesting sites for solitary bees. The importance of having areas of short and longer (flower rich) grass in a lawn to cater for mining bees, which need warm soil to complete their lifecycle, was emphasised.
We recommend walking the Salisbury Bee Trail which Rebecca is responsible for laying out and for which she won an award.
by Peter Shallcross
This month we welcome Rebecca Twigg, founder of Salisbury's Secret Garden.
Rebecca is an organic gardener with a passion for the natural world who received a DEFRA award for the Salisbury Bee Trail project. She has now started a new community garden at the Five Rivers Health and Well-being Centre and an additional ‘green space kick start’ scheme for those wanting to take on a patch of ground themselves.
“Exploration outside is absolutely in my heart, there is something magical about immersing yourself in nature …these interactions shape our values and abilities to manage in an ever-changing world too.”
As last month, the Victoria Hall bar will be open from 7:00PM to serve wine, beer and soft drinks before the meeting.
We plan, as usual now, to live-stream Rebecca’s presentation over Zoom for anyone not able to attend in person; I’ll send out the Zoom link to members a few days before.
Attending our meetings is free for members and anyone under 21; adult visitors are asked for a £2 contribution. If you are not a member but would like to come along, please get in touch via the contact form. The Victoria Hall is on the High St, Tisbury, opposite the garage.
Peter Shallcross will be leading a river walk from Wylye to Fisherton de la Mere this coming Thursday, starting at 7pm. The distance along the footpath beside the river is around a mile each way, pretty flat and sound along its length, so not particularly onerous.
Members don't need to register but if you'd like to come as a guest please let us know via the contact form.
To share car spaces and conserve fuel, meet at the Nadder Centre car park at 6:30PM or alternatively make your own way to Wylye for 7:00PM.
The rendezvous point is a layby immediately after the river bridge on the main road north of Wylye, after passing the Bell pub on your right: see https://goo.gl/maps/9jAP7xYZqvhWn3Qp6
And you may care to bring with you a picnic to enjoy in the churchyard before heading home again.
The following request has been submitted by Jessica Perry of the RSPB Volunteer Monitoring Farm Wildlife project.
"The RSPB Volunteer Monitoring Farm Wildlife (VMFW) project aims to provide a match up service for volunteer surveyors and farmers. The project objectives are to provide a wildlife surveying service to farms, offer opportunities for people to get out into nature and use the collected data to create useful outputs that will help farmers to adapt to nature friendly farming practices.
This is currently a pilot project so many aspects are in development. The taxa surveys taking place in Wiltshire this year are pollinators, butterflies, and bumblebees. We hope to take up more taxa in future years, such as birds and plants. The surveying methods are all citizen science based, so are easy to learn and conduct, but with practice can become a valuable skill.
We try to match volunteer surveyors to farms within a reasonable travelling distance. We may be able to reimburse some travel expenses. Once a match is agreed we send the surveyor the contact details to get in touch with the farmer.
First there is a 'Meet & Greet' session where you agree with the farmer where and what to survey and do a risk assessment. Then surveys are conducted throughout the spring and summer. Results are submitted online by the surveyor. At the end of the year, we will turn those results into useful outputs for the farmers.
It is completely up to you, which taxa to survey, although sometimes a farm might express an interest in a specific type. You can do more than one taxa if you wish and you can do more than one farm if you wish. We cannot always guarantee that a farm is nearby, however we do occasionally run training sessions and encourage our volunteers without farms to practice their skills at their local green space.
The surveys differ a little in how often they are done, bumblebees can be monthly or 3 surveys throughout the surveying season (now until Oct), pollinators are monthly (now until Sept) and butterflies are fortnightly (now until Sept).
Bumblebee transects are 1-2km. For butterflies you select up to 5 areas to survey and pace evenly through that area for 15 minutes recording species. For pollinator surveys the surveyor observes an area of target flowers e.g. clover, for 10 minutes, recording the pollinating insects that visit the flowers.
We currently have several farms in south Wiltshire who need volunteer surveyors. There are two farms in the Tisbury area, one in the Semley area and one east of Gillingham. If anyone is interested in being involved in the project or to help us cover these farms please contact me at firstname.lastname@example.org"
This striking photograph of a Dark-edged Bee-fly was taken recently by Dick Budden, as it rested on a clothes peg of his washing line. The Dark-edged Bee-fly is the most common of the bee-fly species and can be seen mainly in April and May as it feeds with its long straight proboscis on the nectar from spring flowers in gardens and hedgerows.
It is parasitic in behaviour. The female deposits her eggs into mining bee nesting areas by hovering a few inches above, then giving a sharp twist of her body as she flicks her eggs out with a covering of dust that she’s collected specially for the eggs’ protection. Upon hatching, her larvae will then burrow down and lie in wait to feed on the host bee’s larvae when they mature.
You can contribute to Bee-fly Watch on the Dipterists Forum of the Biological Records Centre, where they would welcome accounts of your sightings.
Mid-March into early April is the time of a “blackthorn winter”: a cold spell when the blackthorn is in bloom. This is perhaps because the combination of different strains of the species and the varied micro-climates of their growing locations mean that you can find blackthorn in flower somewhere for more than a month, during which it is likely that there will be at least one cold spell. Or perhaps it is that blackthorn scrub, with its clouds of flowers at their peak, look like the bushes have been covered with snow.
The small white flowers bloom on short stalks from buds along the spines and do so before the leaves appear. En masse, the bloom provides a welcome early source of nectar for insects. These pollinate the flowers, which then develop the distinctive blue-black sloes.
The tree grows naturally in scrub, copses, and woodland, and is commonly used to form a cattle-proof hedge. It favours sunny positions, and when left uncut can develop into considerable thickets, such as those in the Oddbrook valley. Mature trees can grow to a height of around 6–7m and live for up to 100 years. The deep brown bark is smooth, and twigs form distinctive, straight, side shoots which develop into thorns. Its trunk and stems form a dense wood which is good for burning and straight stems have been used for walking sticks, including the Irish shillelagh.
The foliage provides food for the caterpillars of several moths. The dense thickets provide sheltered nesting sites for birds, which then feast on these caterpillars, and later on the sloes.
The scarce brown hairstreak butterfly lays its eggs on blackthorn. This is the largest and brightest of the hairstreak butterflies, the female looking a gorgeous golden colour in flight. However, in common with other hairstreaks, it is quite a small butterfly and notoriously easy to overlook. They spend most of their adult lives perched in the tops of trees, out of sight, lapping honeydew from the leaves. If you are lucky, you might see a female when she descends to lay eggs, nearly always on blackthorn twigs in hedges or bits of sheltered scrub.
Our knowledge of the local distribution of this butterfly is improving all the time, due to the efforts of a small number of lepidopterists who tirelessly search suitable locations for these tiny eggs. Correctly identified, these are a reliable indicator of presence, although not necessarily breeding success, but gets around the difficulties of spotting an adult on the wing. The population appears to be spreading westwards from the area north-east of Salisbury. As eggs have been found in the vicinity of Grovely Wood, who knows, they may be present hereabouts without being recorded. Eyes peeled this August/September.
by Andrew Graham
Slugs and snails have a true champion in Imogen Cavadino, an entomologist who is carrying out research for the RHS. We were treated to a wealth of information with up-close-and-personal photography of these oft-maligned creatures.
Slugs evolved from snails as they simplified their coiled shells and diverged into different families. There’s even such a thing as a semi-slug, one that can’t retract into the shell it carries on top. Some slug species still have a visible pale mantle under the surface, marking their vestigial shell which serves as storage for calcium salts.
The majority of snails have shells which coil to the right, developing asymmetrically via torsion, so that both their respiratory pore and anus end up on the right side of their heads. They are so dependent on moisture that if deprived, they can create an epiphragm to seal themselves in and succumb to a dormant state. Quick to revive if the conditions improve, Imogen told us that a snail was once stuck on a postcard as an exhibit in the British Museum (before they knew about their dormancy behaviour) and stunned everyone by making an escape.
For a researcher, the slime colour can be useful for identifying the species. Slugs produce two types of mucus for defence and movement. We heard that the netted field slug (deroceras reticulatum - above on the left) is the most harmful to our agricultural activities, making a feast of root vegetables in the autumn, but the cellar slugs (Limacus sp. - on the right) feed on rotting material, fungi, lichens and algae and are therefore blameless.
The Royal Horticultural Society (RHS) has been campaigning, with Imogen heavily involved with their media activity, to dispel the myths that all slugs are enemies of the gardener. The last big slug survey was done in the 1940s and the RHS’ recent research has been aided by a formal survey conducted by 60 chosen participants around the country, who performed scheduled slug counts, with the glorious total of 21,000 slugs collected and identified in one year.
They discovered that non-native species were becoming more dominant, no doubt hitching rides on plants from other countries. New varieties are also being discovered, like the ghost slug (Selenochlamys ysbryda - above centre) with no eyes, first identified in Wales in 2014.
Finally, that all important question – how do you euthanise a slug? Obviously, only the types which are eating your veg – please identify them first! The most ethical way is to put them in a sealed container and place in the freezer. Or if you are wanting to maintain their colours for identification purposes, you can drown them in carbonated spring water.
On a more positive note, the RHS welcomes recordings from anyone who wants to get involved. You will find information from Imogen on our Wildlife Recording page, about helping to record slug and snail activity.
At 7:30 pm this coming Thursday in the Victoria Hall, Imogen Cavadino is coming to share her knowledge about slugs and snails.
Imogen is an entomologist currently carrying out research funded by the Royal Horticultural Society (RHS) to help in identifying their species, and to discover which ones are responsible for damaging plants, whether in gardens, on farmland or in the wild.
She aims to inform pest management strategies so that only those slugs and snails that are actually damaging plants are targeted, reducing control costs as well as potential harm to other wildlife.
Photo: Barn owl
The headers display photos taken by our members. Do get in touch via the Contact Form if you'd like to submit a photo for selection.