Green hairstreaks at Barnack Hills and Holes

On the way back from a site survey in Cambridgeshire, I had the opportunity to call by and take my lunch break in Barnack Hills and Holes in the sunshine. Having seen a photograph posted by Nottinghamshire Wildlife Trust the previous day, I knew that green hairstreaks were on the wing so I went off in hunt of these iridescent little jewels!

Green hairstreak (Callophrys rubi) can be hard to track down for a few reasons; firstly, they are wonderfully camouflaged against the leaves – seeing one at a flower can be almost like noticing that one of the leaves is drinking! Secondly, their populations can be small – some colonies are only a few individuals strong and so tracking them down on a large site could be time consuming.

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Spot the hairstreak drinking from the hawthorn flower!
Luckily, after a pleasant half an hour wandering through the cowslips and orchids, I came across several on a hawthorn shrub. It was a windy but sunny afternoon and this hawthorn bush was more sheltered than many others. When in flight, the butterflies reveal the brown uppers of their wings making them easy to spot on the wing – but they always rest with their wings held together and blend beautifully into the greenery.

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Green hairstreak amongst the hawthorn leaves
I watched two males take up sentry posts, settling on hawthorn buds or leaves, poised to leap into action and defend their territory against intruders. Other males were the most targets likely to be chased, along with other insects and butterflies of other species, but they also use this vantage point to spot females on the wing. When resting and waiting, these males tilted their wings towards or away from the sun, micro-managing their temperature with these movements.

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Male green hairstreak poised on a hawthorn bud ready to intercept intruders
Green hairstreaks are widely but locally distributed in the UK – this means there is likely to be a colony somewhere near you but they have particular habitat requirements so you might need to go to just the right place to find them. They occur in a range of habitat types including dry heathlands, grasslands, old railway embankments, woodland and quarries. The key habitat requirement seems to be open grassland with a good scrub component. Adult food plants include trefoils, vetches, hawthorn, gorse and spring flowers such as cowslip and bluebell. The larval food plants are similarly diverse including trefoils, dogwood, vetches, gorse and broom.

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Green hairstreak on a hawthorn flower – one of the favoured food sources for the imago (adult butterfly)
These butterflies are on the wing early in the year – often in April and early May through to early-June or perhaps later in the north. Barnack is a great place to spot them but this site can help you find a location near you!

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Green hairstreak standing guard over his territory on a hawthorn flower
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Walking in the footsteps of Laurie Lee

Cider with Rosie has to be one of my favourite books, with its evocation of life in a wooded Gloucestershire valley at a crucial time when the world around the village was changing but where a more ‘traditional’ country life still persisted. I have wanted to visit the landscape ever since reading it, but it is always that little bit too far or not quite convenient – however a recent site visit took me back past Stroud and so opportunity knocked to call in at Slad – the village where the book is set.

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Look carefully for tiny eyebrights in the grass – their white petals paint-splashed with yellow and purple

I parked up at Swift’s Hill – a SSSI which overlooks the valley and took a look around the grassland before setting off on a walk. The sward is clearly past its summer finery but many flowers still studded the hillside – small scabious, devil’s bit scabious, knapweeds ad eyebrights – frequented by these beautiful little Lasioglossum solitary bees with endearingly long antennae.

I then picked up the Laurie Lee Wildlife Way which takes you down the steep hillside and across open pasture field to an apple orchard where the mustard-green mistletoe nests amongst the branches.

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The view across the valley to the village of Slad with mistletoe hanging from the apple trees in silouette

Next, the path takes you down across the river and into the village itself, before heading up the other side of the valley and into the darker woodlands of Frith Wood where the trees crowd over the pathway to form a shady passageway between the trunks. After crossing the road, and walking beneath some truly majestic beeches, the track winds up a steep wooded hillside and releases you into the meadow of Snows Farm – managed for wildlife and thronged with flowers such as yellow agrimony, blue harebell and scented wild basil and marjoram.

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An old trackway with majestic beech trees lining the way

The way continues then through woodland and wildflower grassland, ending in Laurie Lee wood – a recent Gloucestershire Wildlife Trust aquisition – before ending back at the high open hillside of Swift Hill.

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The view out across the valley with Russian Vine covering the foreground

One of my favourite aspects of the walk was the totems displaying Lee’s poem’s written black on perspex so that the view was visible behind the words. This means of display was an excellent way of placing the poems within the landscape which was so important in inspiring his work.

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After reading Cider with Rosie, I read ‘As I Walked Out One Midsummer Morning’ where Laurie Lee talks about leaving this very village on foot and working in London before making his way to the continent and walking down to the south coast of Spain. The steep valleys and hillsides would be fine training for a long distance walk and I could certainly feel my flatland legs when I got to the end, but this was a magnificent way to spend an afternoon through some of the most quintissential Cotswolds scenery you could hope for. Woodruff and wood sorrel leaves covered the woodland floors, whilst the dead flowering stems promise bluebells in the springtime so I will certainly be back to explore this beautiful place again.

You can read more about the Laurie Lee WIldlife Way here. I didn’t have a copy of the route guide but found the walk quite straightforward to follow for the most part – however there are places where crossroads are not signed so it’s a good idea to pick up the leaflet or to take a map with you as backup!

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The view across pasture fields to the orchards, with the wooded hillside rising to the right hand side

Bonsai botany

Chalk grasslands on downland are often case of bonsai botany – the low nutrient status due to the chalky substrate, combined with grazing by sheep or cows favours low creeping species, or those willing to operate in miniature.

Squinancy wort - Asperula cynanchica
Squinancy wort – Asperula cynanchica

Squinancywort is a small, mauve-lilac flowered member of the bedstraw family, of which the strong, scrambling sticky-weed or cleavers is perhaps the most commonly known example.

Ladies bedstraw - Galium verum
Ladies bedstraw – Galium verum

Ladies bedstraw is another member of the bedstraw family – the four-petalled flowers are common to all members of the bedstraws although the majority are white – ladies bedstraw is one of two yellow flowered members of the genus.

Beaked Hawk's-beard - Crepis vesicaria
Beaked Hawk’s-beard – Crepis vesicaria

Beaked hawk’s beard is usually a more robust plant, but here it was growing in a low, creeping habit. The red-flecked undersides to the petals however make it distinctive.

Common restharrow - Ononis repens
Common restharrow – Ononis repens

Common restharrow is a low-growing member of the pea family with beautiful, striated foxglove-purple flowers.

Bird's foot trefoil - Lotus spp.
Bird’s foot trefoil – Lotus spp.

Birds-foot trefoil is another member of the pea family with sunshine-yellow flowers. It is quite a common sight, often included in wildflower mixes and a big hit with many of the butteflies such as the skippers and the blues.

Kidney vetch - Anthyllis vulneraria
Kidney vetch – Anthyllis vulneraria

Kidney vetch is a third member of the pea family – the flower heads contain clusters of the small pea-flowers – just as the bird’s-foot trefoil but multiple and in miniature.

Small scabious - Scabiosa columbaria
Small scabious – Scabiosa columbaria

Small scabious is a a soft lilac coloured flower with open heads which attract a wide range of pollinators including solitary bees, bumblebees and butterflies.

Round-headed rampion - Phyteuma orbiculare
Round-headed rampion – Phyteuma orbiculare

Round-headed rampion is something of a rarity nationally, but was quite common in patches of the grassland on the south downs. It is the County Flower of Sussex and quite a striking blue up close. It seemed to be a particular favourite of the six-spot burnet moths which had just emerged, judging by the empty pupae cases lining the dry grass stems.

The downs have a particular character of their own, but many of the species above (with the exception of the rampion) can be seen much closer to home in the Midlands – there are a number of excellent calcareous grassland sites around Grantham, the finest of which has to be Barnack Hills and Holes NNR just down the A1 near Stamford but a number of other Lincolnshire and Leicestershire Wildlife Trust sites also boast an exciting range of calcareous meadow species – use the Nature Finder app to see what is closest to you.