Monday 18 July 2022

Holkham guided walk, 15 July 2022

A select group of four Honeyguiders met at Lady Anne’s Drive on the Holkham estate on a warm and sunny July morning. Our target for the day was creeping lady's tresses, a diminutive white orchid which is scarce but widespread in the native pine forests of Scotland but with an odd out-lying population at Holkham in the pine woodlands that were planted to stabilise the sand dunes in the 19th century. The origin of the Holkham population is uncertain - some think they might have been inadvertently introduced on trees planted in the dunes that had been grown further north. We will never know for sure.

'Gatekeeper among thousands' (Jillian Macready).
Walking out along the track running westwards behind the pines, it was obvious that it was peak emergence time for gatekeeper butterflies - they were everywhere. Also on the wing were speckled wood, green-veined whites, large and small skippers, peacock and red admiral.

 Hoverfly Eristalis pertinax (Rob Lucking).
Several great pied hoverflies Volucella pellucens hovered in front of us, occasionally landing – once on Malcolm’s hat! – and allowing to see its glossy black thorax and abdomen with a white stripe between the two. There were other hoverflies out as well but the only one we could identify from photos was Eristalis pertinax. There were also several large robberflies - possibly hornet robberfly judging by their size.

Robber fly sp (RL).
By Meals House we looked in the old cart barn for evidence of ant lions and found several of their shallow, conical pits. Helen did her best to entice some of the larvae out but to no avail. Maybe they had already flown.

Ant-lion pits among the brickwork (JM).

As we neared the end of the pine woods, we cut through towards the beach to the area of dunes where the creeping lady's tresses are found. Some forestry work had been carried out along the track and the more open areas had quite a lot of ragwort growing which in turn held caterpillars of the cinnabar moth. We also found several plants of lesser centaury. As the woodland opened out onto the dunes, we found that the creeping lady's tresses area had been roped off and within it we found at least eight spikes - some tightly closed and the others fully open.

Creeping lady's tresses (JM).

Megachile leachella, male on fleabane (JM).

Two bees photographed by Jillian, with IDs confirmed later, are of note. Silvery leafcutter bee, Megachile leachella, is the UK’s smallest leafcutter bee; the green tinge to the eyes is a feature. The BWARS website shows a coastal distribution for this species.

Heriades truncorum, female, also on fleabane (JM).

Heriades truncorum is also scarce (see BWARS website), though spreading, and is often - though not always - associated with pines, using resin to build partitions of its nest, liking dead timber with suitable-sized beetle holes, in the sun and with yellow composites, often ragwort but today fleabane.

At this point Jillian departed for Warham Camp and the rest of the group had lunch looking out over the beach. It was the section of beach frequented by naturists so we didn’t look too closely!

After lunch we walked west through the dune slacks looking for a butterfly speciality – the dark green fritillary. It didn’t take Helen long to find the first one - a rather worn specimen but it did at least sit still for long enough for us to give it good grilling and we even saw the dark green underwing for which it is named.

Holkham collage. Clockwise from top left: Six-spot burnet moth on willowherb; emperor dragonfly devouring the soft parts of a peacock butterfly which it had just caught on the wing (somehow it sucked the innards out, which were egg-yolk yellow); creeping lady's tresses, cinnabar moth caterpillars (we must have seen hundreds, they were on every ragwort plant) (Helen Crowder). 

As we wandered through the dunes, we found several more dark green fritillaries and also watched an emperor dragonfly catch a peacock butterfly in flight and take it down to the ground to eat.

The dunes themselves were very parched but we did find some common centaury and lots of haresfoot clover.

Common centaury (JM).

We retraced our steps back towards the car park. There were a lot of very fresh and brightly coloured ruddy darters sunning themselves on the track. We also found a couple of new butterflies for the day – brown argus and small copper. We stopped and lingered next to a stand of elms which have proved good in the past for white-letter hairstreak but it was getting a bit late in the day; the breeze had picked up and we drew a blank. A large, pale brown insect flew past quickly and did several circuits – not a butterfly but an oak eggar moth!

Jillian reported a successful visit to Warham Camp where she had seen chalkhill blue butterflies which added to the 15 species we recorded at Holkham gives us a very respectable 16 species overall! 

Chalkhill blues at Warham Camp (photos by JM).

Rob Lucking

Saturday 2 July 2022

Buxton Heath and Holt Lowes, 1 July 2022

Today’s event was inspired partly by bringing some Honeyguiders together for Lyn, visiting from Cambridgeshire, and partly by happy memories of the same event a year ago [Buxton Heath and Holt Lowes, 2 July 2021]. Same places, but a rather earlier summer this year with wildlife that was sometimes different as a result.

The star species at Buxton Heath is silver-studded blue butterfly. On a day of rather changeable weather, would they be on show? In the end it was straightforward as there were several that were easy to see on the bell heather very near to the car park. The heatwave in June meant that they were towards the end of their season, and some were looking quite tatty. Happily, we did find one where the ‘silver studs’ showed well, especially looking though the telescope.

Silver-studded blues: on the right hand butterfly above, you can just about make out the silvery-blue 'studs' in the dark spots above the orangey-brown marks.

Yellowhammers are getting scarcer in the countryside so two that perched in clear view were much enjoyed. We added linnet, reed bunting and stonechats a little later for some, and a willow warbler was singing from time to time, as well as more expected chiffchaffs and blackcaps.

Moving into the boggy area, it seemed clearer of tall vegetation than a year ago, which is generally good, though there were fewer orchids. But we did find a few marsh helleborines plus many pale pink marsh orchids, always tricky to ID with certainty here with the range of species and hybrids that occur. More certain was a mass of bog pimpernel, marsh lousewort, lesser spearwort, tormentil, ragged robin, fen bedstraw and leaves of marsh pennywort on mounds of sphagnum moss.

Marsh helleborine.

We found an area that was dry enough for us to stand and overlook patches of open water over which several powder blue keeled skimmers moved to and fro, settling from time to time. With these were four-spotted chasers that were dipping into the water to deposit eggs.

Cross-leaved heath.
Two naturalists were watching us and wondering what we’d found. It transpired that they were visiting Norfolk from Sussex to celebrate their golden wedding. Fittingly it was a golden-coloured female keeled skimmer that we had focused on, nicely settled on an open patch of ground between patches of pale pink cross-leaved heath.

Keeled skimmer, female.
We walked a little way into the drier part of the heath, past a small pile of jay feathers, presumably a sparrowhawk casualty. We were mostly looking at butterflies. Meadow brown and ringlet were the commonest, and we had good views of large skipper, too.

Jay feathers.

As we drove north towards Holt there was a distinct change in the weather, including rain. We were glad to have packed lunches on Holt Country Park’s sheltered picnic benches, and to grab a hot drink from Hetty’s kiosk. That said, it couldn’t have rained at a more convenient time, and it began to clear up as soon as we were on the move.
Silver-washed fritillary.

We checked out the buddleias in the car park where there was only a limited amount of flower and only a single red admiral. But no matter: we were just a short distance into the open woodland and, hey presto, four silver-washed fritillaries appeared on bramble flowers, looking pristine and freshly emerged. The golden wedding couple had followed us to Holt Country Park and, as they joined us, their sought-after butterfly appeared: a lovely white admiral, fluttering around its larval food plant, honeysuckle. The weather must have changed as a blackbird was sunbathing.

Sunbathing blackbird.

There were more four-spotted chasers and several damselflies – and willow emerald egg-laying scars – at the big pond.

Out on Holt Lowes, we took our usual clockwise circuit. Once we’d reached the boggy areas that surround much of Holt Lowes, the search was on for alder buckthorn. Could we match last year’s experience of watching a brimstone laying eggs on its larval food plant? Well, yes and no. There were no adult butterflies, though we did see some eggs. Instead, it was all about caterpillars. Ann – no surprise there – was the first to find a green brimstone caterpillar, then Helen, then the rest of us – even me – got our eye in for finding our own. This is no easy feat as not only are they camouflaged by colour, they were along the mid-rib of alder buckthorn leaves, which also helps to hide them.

Play 'hunt the brimstone caterpillar' ...

Alder buckthorn again, this time with a
scorpionfly Panorpa communis or P. germanica.

There were a few keeled skimmers, though fewer than at Buxton Heath. We couldn’t find any marsh helleborines – perhaps it’s a poor year for them. As at Buxton Heath, pink bog pimpernel was looking lovely, near which were the yellow flowers of marsh St John's-wort. Cheryl puzzled about the absence of buzzards, at which point one appeared. We heard a garden warbler, singing in unusually short bursts for this species, the ID confirmed by the Merlin song recognition App.

Marsh St John's-wort, Hypericum elodes.

Brown china-mark moth, Holt Lowes.

We passed the wood with the carpet of hair cap moss and continued to find more and more alder buckthorn, and every damp area seemed to have more sundew leaves than the last, many with slender spikes of flowers in bud. 

Round-leaved sundew, with pink-flowered bog pimpernel.

Back by the pond, a southern hawker flew past and settled in its characteristic vertical hanging position on a very small cypress tree in the gloom.

Southern hawker.
Chris Durdin

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