Mill Hill (June 2013)
Spring Downland Butterflies (May):
Adonis Blues (Photograph                    by Andy Horton)
Dingy Skipper                    (Photograph by Andy Horton)
Small Heath Butterfly
Grizzled Skipper
Adonis Blue Butterfly
Dingy Skipper
Small Heath Butterfly

Noticeable summer plants of the upper meadows include Greater Knapweed, Hardheads (=Lesser Knapweed), Field Scabious, Meadow Cranesbill, Alexanders, Pyramidal Orchids, Plantains, Melilots, Meadow Vetchling, Yarrow, Eyebrights, Musk Thistles, Hounds-tongue*, Perforate St. John's Wort*, Great Mullein* and many others. Herb Robert is found amongst the scrub.
(*notably on disturbed ground.)

Some Indicator Plants of Ancient Downland

Horseshoe Vetch (Photograph by Andy Horton)
Autumn Gentian
Horseshoe Vetch
Common Milkwort
Dog Violet
Autumn Gentian

Other indicators on the lower slopes include Dropwort, Autumn Ladies Tresses (upper plateau), Hairy Violet, all of which are rarely found on pastures, restored wildlife meadows or agricultural downland. Other downland plants that are more likely on the biodiverse down herbland are Wild Thyme, Carline Thistle, Dwarf Thistle, Squinancywort, Fairy Flax, Small Scabious, Common Centaury and Wild Basil. There are other more widespread wild plants like the Mouse-eared Hawkweed, Rough Hawkbit, Lesser Hawkbit, Bird's Foot Trefoil, Ground Ivy, Germander Speedwell, Field Speedwell, Sweet Violet, Self-heal and Yellow Wort.
Wild Flora and Fauna on Chalk   flickr
Adur Wild Flowers 2020


A large part (724 acres) of the downs including Mill Hill were presented to the people of Shoreham in 1937

Lower Slopes of Mill Hill, May 2006 

Just over 30 acres still remain as public open land and a Local Nature Reserve.  This is divided into about 11 acres of grassland and meadows above the ridge, about 9 acres of scrub, the copse and glades at the northern end, and about half of the prime Chalkhill Blue area of 6.4 acres of herbland remaining. 6 acres has been lost to a Sycamore woodland on the southern slopes. 

This is low fertility chalkland not suitable for grazing. The top area is effectively a wild meadow and the lower slopes a rabbit warren dominated by prostrate (not the upright form) Horseshoe Vetch, Hippocrepis comosa

Link to                            the Mill Hill web page for 2009

Horseshoe Vetch

Chalkhill Blues:

Mill Hill is nationally important because of its population of Chalkhill Blue Butterflies. Estimates of the numbers are notoriously inaccurate. In the 1950s the population was estimated by R. M. Craske to be 50,000. This may be an exceptionally good year. I would estimate the numbers at that time to be nearer 25,000 for Mill Hill only. After the cattle grazing and thorn incursions the numbers plummeted to the most reliable estimate in 1960 of 6,000. The new road and Sycamore woodland further denuded the Horseshoe Vetch, Hippocrepis comosa, and bare chalk downland to a figure I have estimated at a top figure of 3,000 Chalkhill Blue Butterflies at the turn of the millennium (counted in 2003). Almost all these butterflies are now to be found on the six acres of the lower slopes.
Graham Hart in the 1990s estimated the numbers at 6,000. This is not out of the question and this would accord with the R. M. Craske estimate of 50,000. This would be the maximum population density that could be expected on the carpets of Horseshoe Vetch (based on German figures).
Protection of the current population requires man management of the scrub incursions, which means removal of the Privet

Text by Andy Horton Calcareous Grassland Message
"Our family lived at The Mill House, Mill Hill, from around 1933 until about 1967, and every July we saw the "Butterfly Men" walking past onto the Downs. My father used to tell us that they were interested in the blue butterflies."
Heather Clark (née Eager), Ryde, Isle of Wight
Nearest Postcode:  BN43 5FH
Grid Ref:  TQ 21170 07444  (upper car park)
Geographic Link      OS Map
Google Earth Map
Magic Map of Mill Hill NR
Local Nature Reserve Designation
Natural England: Local Nature Reserves
Multi-Map (Bird's Eye View)
Grid Reference Finder

Threats to the Butterfly Downland site at Mill Hill
The butterfly lower slopes at Mill Hill are under serious threat by a natural process known as ecological succession where the woody shrubs like Privet, Brambles and Hawthorn invade the herb-rich slopes gradually turning the downs into woodland and eliminating the butterfly larval food plants especially the Horseshoe Vetch, Hippocrepis comosa, on which the Chalkhill Blue Butterflies rely. The remedy is by expert professional removal of the Privet on a regular basis. This job is now being undertaken by volunteers. 



Mill Hill on

Mill Hill on


OS Map

   Footpaths at Mill Hill

Map Geograph Satellite


Mill Hill Wildlife Reports 2021 (Link)

21 September 2020

There were well over a hundred Common Blue Butterflies on a sunny Mill Hill. more on the top than the lower slopes. Over 70% were the bright blue males, with females having a blue tinge and some were mating in flight. Other butterflies included occasional Wall Browns, at least two very bright yellow and restless Clouded Yellows, a few Large Whites, and at least one Meadow Brown.
Devil's Bit Scabious was in flower on the lower slopes but it was only an occasional magnet for butterflies in the early afternoon.

20 September 2020

Clouded Yellow on Mill Hill
Photograph by Glynis Pierson

15-16 September 2020
Fifteen species of butterfly were seen on Mill Hill including several Wall Browns and a Clouded Yellow.

Illustrated Report by Neil Coleman
Mill Hill Nature Reserve on facebook

14 September 2020

Small Copper on Hoary Ragwort
Report & Photograph by Keith Wells
Adur Valley & Downs facebook

18 August 2020

A Wasp Spider, Argiope bruennichi, was spotted on Mill Hill in the afternoon.

17 August 2020

Chalkhill Blues, Hornet Robber Fly

About a hundred lively butterflies on the lower slopes of Mill Hill, on a humid afternoon, were led in frequency by Meadow Browns, with Chalkhill Blues, Common Blues, Adonis Blues, Small Heaths, Large Whites, and two restless bright Clouded Yellows. Add on a few Gatekeepers, one Wall Brown. two Speckled Woods and an ambush predator the Hornet Robber Fly around the winding path and southern steps. There were significantly more Meadow Browns, Common Blues and Small Heaths south of the Reservoir.
Adur Flies

8 August 2020

Pretty Chalk Carpet Moth, Melanthia procellata
Mill Hill
Report & Photograph by Keith Wells
Adur Valley & Downs facebook

5 August 2020
There were at least ten male Chalkhill Blues fluttering over the southern bank of the Mill Hill Cutting on a sunny afternoon. There were an estimated forty more seen on the lower slopes of Mill Hill. The Kestrel hovered over the Old Erringham pasture.

2 August 2020
With a breeze blowing the flowers about there were scores of butterflies fluttering over MiIl Hill and nearby (in a good year, this would be hundreds) of nineteen different species: Chalkhill Blues (estimated 35 males+2), frequent Common Blues, Painted Lady, (one at the top of Chanctonbury Drive), frequent Gatekeepers, and occasional Meadow Browns, a Speckled Wood in the copse. and a mating pair of Wall Browns plus one more, male Adonis Blues (4), a Red Admiral and a Peacock Butterfly. two Holly Blues in the scrub, a Large White and a Small White, two restless bright Clouded Yellows, a tatty second brood Dingy Skipper on the lower slopes, a tatty Small Skipper and a Brown Argus in the top meadow, a few bright yellow Brimstone Butterflies, and a Small Heath on the middle slopes. Six-spotted Burnet Moths were attracted to purple flowers, especially Dwarf Thistle and diminutive Hardheads (Lesser Knapweed).

A mating pair of Wall Browns

Sloe Berries appeared on the Blackthorn. The green shoots of Carline Thistle appeared on the middle slopes. The first Hawkweed Ox-tongue flowered on the lower slopes.

2003 Report

30 July 2020

Common Blue Butterflies
Photograph by Sarah Mitchell

"It was a beautiful, warm evening. We walked, talked, stopped and sat down on the bench taking in the stunning views. We continued with our walk and on the way back to the car park saw a Common Blue Butterfly. This took our interest. Then we saw another, and another, and another. We couldn't believe our eyes as on looking closer there must have been at least a hundred plus butterflies just sitting on the stems of grass and plants sunbathing in the sun."

Report by Sarah Mitchell
on Mill Hill Nature Reserve  facebook

29 July 2020
Under a clear blue sky, butterflies were frequently seen on a hazy afternoon. This was to be expected and nowhere near a good day. On the top of Mill Hill. amongst the long grasses, male Common Blues quickly appeared and one Brown Argus, frequent Gatekeepers, and occasional Meadow Browns.  Over the southern steps to the lower slopes there was a Speckled Wood and a Wall Brown. The lower slopes were parched with less nectar flowers than usual. A restless bright yellow Clouded Yellow Butterfly was seen after a few minutes. A pair of Brimstones were fluttering from flower to flower. A Red Admiral and a Peacock Butterfly gave a large splash of colour in contrast to a Large White.

Chalkhill Blue

The lower slopes also hosted at least thirty male Chalkhill Blues, occasional Common Blues, including a female, occasional Meadow Browns,
including a mating pair, Gatekeepers amongst the bushes, one Small Heath, a faded Small Copper and a dozen Six-spotted Burnet Moths on purple flowersA few pyralid moths were spotted the lower slopes of Mill Hill  in the warm sunshine, occasional Pyrausta purpuralis and Pyrausta despicata.

24 July 2020
A Peregrine Falcon caught a Starling over Mill Hill.

Illustrated Report by Sylvia Lemoniates  facebook
22 July 2020

Female Sparrowhawk hunting over Mill Hill
Photograph by Sylvia Lemoniates  facebook

22 July 2020
On a warm energy sapping humid afternoon, my visit to MiIll Hill was not as long as I would have liked. On the southern part, south of the Reservoir, amongst the parched long grasses, and all the stages (including the silver discs) of Greater Knapweed,   I disturbed frequent butterflies: male Common Blues (10+), at least one Brown Argus, frequent Gatekeepers, occasional Meadow Browns, one Large White, at least one Marbled White, and one Red Admiral. Fleabane was in flower. The first Wild Parsnip appeared.

Brown Argus, Wayfaring Tree, Common Blue
Chalkhill Blue

Down the southern steps past the Wayfaring Tree on to the lower slopes where a "helice" Clouded Yellow was seen very quickly, but not for long as it fluttered rapidly between nectar plants, almost exclusively Wild Basil. Widespread and frequently seen, at least thirty male Chalkhill Blues were very lively, like all the butterflies in the sunshine, including a few male Adonis Blues, more male Common Blues, Gatekeepers and Meadow Brown Butterflies, one Brimstone Butterfly and Six-spotted Burnet Moths.

Greater Knapweed, Fleabane, Ploughman's Spikenard
Small Scabious

Ploughman's Spikenard was seen in flower for the first time this year as well as a diminutive Round-headed Rampion.

20 July 2020

Yellowhammer (male of a pair) on Mill Hill
Photograph by Tony Gould
on Mill Hill Nature Reserve  facebook

17 July 2020

Kestrel windhovering on Mill Hill
Photograph by Sylvia Lemoniates  facebook
There was a young Kestrel with an adult

13 July 2020
At last, the first Chalkhill Blue Butterfly of the year was spotted on the lower slopes of Mill Hill. It was one of a few males seen in the late afternoon, accompanied by frequent male Gatekeepers, occasional Meadow Browns, male Adonis Blues and male Common Blues, occasional Marbled Whites, a few Small Whites, one lively Peacock Butterfly, one Wall Brown and a few Six-spotted Burnet Moths. The Wayfaring Tree berries had turned red.

Marbled White, Gatekeeper
Chalkhill Blue

At the top of the southern steps down to the lower slopes a worn Dark Green Fritillary visited flowering Teasel.

12 July 2020

Photograph by Sylvia Lemoniates  facebook
Mill Hill

6 July 2020

Photograph by Sylvia Lemoniates  facebook
New Erringham Downs

Summer had just about arrived on a cloudy late afternoon on the lower slopes of Mill Hill, with my first of the year Small Purple-barred Moth, Phytometra viridaria, Shaded Broad-bar and a Six-spotted Burnet Moth, and my first of the year Marbled Whites (3) and Gatekeeper butterflies. I also spotted my first Cinnabar Moth caterpillar on Common Ragwort. Occasionally I disturbed Meadow Brown Butterflies and a Treble-bar Moth. More active fluttering about were a few Large White Butterflies and a brightly coloured Peacock Butterfly. Then to my intense surprise a fluttering bright blue butterfly settled and it was confirmed as a good condition male Adonis Blue. This must be a second brood and it is three weeks earlier than in 2019. There were scores of bright green grasshoppers amongst the short vegetation. Both Great Mullein and Weld were more plentiful than before on the disturbed ground west of and below the winding path. The ground-hugging Dwarf Thistle and Small Scabious were seen in flower for the first time this year. Most of the Deadly Nightshade berries were green but some had turned black. The Wayfaring Tree berries were orange. The Yellow Wort flowers were all closed as it was late in the afternoon.

Vervain, Marbled White, Squinancywort
Small Skipper

As befitting summer, Greater Knapweed was flowering on the southern upper part of Mill Hill, but there were hundreds of heads yet to open. A Red Admiral settled with its wings closed out of camera range. Another first of the year was a Small Skipper in amongst the long grasses. A Kite-tailed Robberfly, Tolmerus atricapillus, waited in ambush on the southern steps. The tiny fruit fly Oxyna was seen on Yarrow for the first time on Mill Hill.
Photo Gallery
Adur Flies 2020

8 June 2020
Bladder Campion was very easily seen in large clumps in the meadow north of  the upper car park on Mill Hill. Two Swifts swivelled and dived over the middle slopes.

7 June 2020
On the southern part of Mill Hill, there must have been two hundred Knapweed Broomrapes and even more of the smaller Yellow Rattle. The first purple flowers of Greater Knapweed appeared, seen in the light rain on a cloudy late afternoon. There were a few small Pyramidal Orchids seen.
Adur Orchids
2 June 2020
The first Large Skipper of the year was spotted on the middle slopes.

 This skipper is scarce in the wild habitats around Shoreham. Only a few are seen on Mill Hill each year.

1 June 2020
A first of the year Cinnabar Moth made a fleeting appearance on the lower slopes of Mill Hill in the middle of the day. Butterflies were all lively on a warm sunny day under a clear blue sky. Small Heaths (20+) were the most frequently seen but there was also a larger  Meadow Brown Butterfly. The blue butterflies were worn at the edges which made them tricky to identify. I eventually determined that at least a dozen were male Adonis Blues with one female and a few were Common Blues and one Holly Blue. Two Brimstone Butterflies patrolled the steeper slopes. There was a probable Brown Argus and a definite Grizzled Skipper.

Grizzled Skipper on Bramble

The tall Yellow Wort and the ground hugging Wild Thyme were both flowering. More of the diminutive Eyebright and the tall Dropwort graced the lower slopes. Hound's-tongue were going to seed nearby. A few Meadow Cranesbill and the first Greater Knapweed were seen on the southern top part of Mill Hill.

28 May 2020
What a difference a week makes: the yellow carpets of Horseshoe Vetch, Hippocrepis comosa, on the lower slopes could not be seen from afar, the flowers having turned to seed. Under the cloudless blue sky the Adonis Blue Butterflies (25+) were frequently seen, the males were very lively and the females searching for somewhere to lay their eggs. They equalled in numbers the other seven species. Small Heaths (16+) were frequent in the sunshine and both these species could be seen above the ridge as I returned by that route. Holly Blues (2+) fluttered over the hedge north of the bridge and a Speckled Wood was disturbed over the southern steps down to the lower slopes. Brimstone Butterflies patrolled the bottom hedge of the lower slopes where a pair of Dingy Skippers danced together, and only a few male Common Blues and one Brown Argus. The most pleasing find of the afternoon was a Burnet Companion Moth. Grasshopper nymphs were heard stridulating.
Adur Butterfly List 2020

Horseshoe Vetch, Hippocrepis comosa

The intrusive Privet, Dogwood and Elderflower were blossoming, but Hawthorn was finished. Yellow Wort and Mouse-eared Hawkweed were seen budding on the lower slopes. A tiny Hairy Violet flower was recognised and there were some more Dropwort flowers.

26 May 2020

Knapweed Broomrape

I made just a very brief visit to the top southern part of Mill Hill on a demonstration ebike where I met Philippa Morrson-Price of the South Downs National Park Authority. Parasitic plants were much in evidence: frequent scattered first growths of the very distinctive Knapweed Broomrape and the small yellow flowers of Yellow Rattle. Wild Mignonette was seen by the layby.
Sussex Rare Plant Register

20 May 2020
A Skylark sang in the Cirrostratus sky, on a sunny afternoon that prompted a visit to the top part of Mill Hill. Frequent butterflies fluttered around: occasional male and female Common Blues, a few each of male Adonis Blues, Brimstones, Dingy Skippers, my first Green Hairstreak of the year, and my first Mother Shipton Moth. A Speckled Wood showed in the top copse where I noted hundreds of Garlic Mustard plants going stringy. Two Holly Blues fluttered around the top of the scrub. Bladder Campion was flowering in the meadow north of the upper car park.

Bladder Campion, Green Hairstreak
BIrd's Foot Trefoil

BIrd's Foot Trefoil joined Bulbous Buttercups and Horseshoe Vetch as the yellow carpets of flowers on the middle slopes and top plateau. Blackthorn was in leaf. Hawthorn flowers were turning brown as the first Elderflower appeared.

Mill Hill upper car park was open for vehicle parking

19 May 2020

Adonis Blue Butterflies

Under a pale blue sky, sheltered  from the easterly breeze, I gave up counting the Adonis Blue Butterflies over the lower slopes of Mill HiIl at fifty (46+4). They were all very lively in the afternoon sunshine and hardly ever settled, even when mating. After completing the lower acre transect I spotted an estimated further twenty, including three mating pairs, as I returned by the winding path. Again, there were occasional male Common Blues, occasional Small Heaths, patrolling Brimstones, and a handful of faded Dingy Skippers. I spotted a briefly settled Small Copper and a similarly transient Brown Argus before they were chased from their perch by larger blue butterflies. There was also a Peacock Butterfly and a Small White.
Although past its peak the Horseshoe Vetch, Hippocrepis comosa, was resplendent, covering the steeper slopes.

14 May 2020
My first two Swallows of the summer flew low over the middle slopes of Mill HiIl. Cumulus clouds cast a shadow over the lower slopes making the appearance of butterflies very patchy and the estimated numbers not necessarily representative of presence. Adonis Blues were seen frequently and all but one of about twenty were the bright blue males. Many more were seen when the sun shined through a gap in the clouds as this caused these butterflies to be active. I had to be careful with recognition as there was at least eight pristine male Common Blue Butterflies behaving in a similar way over the lower slopes. Small Heaths were also seen and I spotted a resting Small Copper and a fluttering Brimstone. Only three Dingy Skippers were seen over the northern end of the lower slopes. A very small grasshopper nymph was spotted amongst the short vegetation.

Eyebrights, Dropwort, Horseshoe Vetch
White Bryony, Common Blue Butterfly

I visited the middle slopes for the first time this year where there was a few male Common Blues and a few Dingy Skippers amongst the fading Cowslips. A Speckled Wood Butterfly was seen at the corner of my eye as I walked into the top copse. Overall the top of Mill HIll was north-easterly breeze blown and deserted.

Summer was inching in with the first diminutive Eyebrights on the lower slopes where there were a few Bramble and Bittersweet flowers and White Bryony. Flower firsts on the middle part of Mill Hill Nature Reserve included Rough Hawkbit, Dogwood and Yellow Rattle. Bladder Campion was budding.

12 May 2020

Mill Hill from the western towpath of the River Adur
The silver flowers are the Hawthorn

8 May 2020

Horseshoe Vetch

A sunny visit to Mill Hill in the afternoon was superfluous and nothing new for the year was seen. Horseshoe Vetch, Hippocrepis comosa, was determined to be at its peak, but the flowering was not as luscious as in the best years. Butterflies were frequent but not as varied as earlier. On the lower slopes Dingy Skippers were everywhere and in the half transect, estimated over thirty singles, as well as over ten Adonis Blues, a few male Common Blues, a few Small Heaths, a few probable Large Whites, and a few patrolling Brimstones. Deadly Nightshade was in flower. I returned by the ridge route and added a Wall Brown and another ten Dingy Skippers.

6 May 2020

Adonis Blues

Butterflies were frequent and lively on a sunny afternoon, notably the first two female Adonis Blues of the year with half a dozen males, with a pair attempting to copulate. I estimated at least twenty Dingy Skippers all over the lower slopes of Mill Hill . Grizzled Skippers only amounted to a probable pair. Other butterflies were occasional Peacocks, at least five Small Heaths, a few wandering probable Green-veined Whites, a few patrolling Brimstones, a first of the year male Common Blue Butterfly, at least one dark Wall Brown and a handful of Treble-bar Moths.

5 May 2020

Dingy Skippers

Draughty and cloudy, conditions not ideal for butterflies but better for photography, I nevertheless enjoyed my afternoon visit to the Horseshoe Vetch covered lower slopes of Mill HiIl. Dingy Skippers were frequent and widespread and on the two-thirds transect I estimated at least 35, including a mating pair. However, I did not actually disturb a single Grizzled Skipper. Other butterflies disturbed from rest were occasional Peacocks, five male Adonis Blues, my first pristine Brown Argus of the year, one Small Heath, and one Brimstone. A Treble-bar Moth showed and a small pyralid moth Pyrausta nigrata were spotted.
Adur Skippers

Adonis Blue

On the floral front a single Dropwort was seen for the first time this year. On the top southern part of Mill Hill I immediately encountered a Large Red Damselfly, near the water trough.
Floral Images

27 April 2020
A Buzzard soared over the lower slopes of Mill HiIl, the accompanying Kestrel looking tiny in comparison. A Common Lizard skittered into shelter after basking on some young Brambles.
Adur Reptiles 2020

Small Copper
Grizzled Skipper

A second day in succession, I visited the lower slopes hoping to get a decent picture of an Adonis Blue, but the one sighting was a flutter of blue for just ten seconds. Two Red Admirals were around the southern steps. I counted 25 Dingy Skippers on a half transect but only the occasional Grizzled Skippers (10+), Brimstones and Green-veined Whites, one Small Heath, one Wall Brown, one Small Copper, three Treble-bar Moths, and three small pyralid moths Pyrausta nigrata spotted amongst the short vegetation on the lower slopes. Another Small Copper fluttered over the grass at the top of the southern steps where Silverweed was flowering.
Adur Skippers
Adur Moths 2020

Hound's-tongue, Weld (or Dyer's Rocket)
Small Copper Butterfly

26 April 2020

Dingy Skipper

Typically, a pristine Wall Brown Butterfly landed on the winding path through the lower slopes of MiIl Hill, in the afternoon. It quickly fluttered away. I counted 28 Dingy Skippers but only the occasional Grizzled Skippers (8+), Brimstones and Green-veined Whites, just the one Small Heath, and three first of the year very lively male Adonis Blues on the two-thirds acre transect walk. A Treble-bar Moth and a small pyralid moth Pyrausta nigrata were spotted amongst the short vegetation on the lower slopes. A Red Admiral fluttered over the Stinging Nettles at the top of the southern steps. Hounds-tongue was budding on the lower slopes. I also identified the rosette of leaves of Weld (or Dyer's Rocket), Reseda luteola. A Kestrel flew overhead.
Adur Skippers

23 April 2020
With scarcely a cloud in the hazy blue sky, the sunshine made the butterflies very lively. At the very top of Chanctonbury Drive, two pairs of sparring Speckled Woods immediately appeared. Almost simultaneously on the Pixie Path side of the road to Mill Hill,  my first three of the year Holly Blues looked brilliant and restless over the Ivy.

Small Heath

On the lower slopes of MiIl Hill, in the middle of the day, butterflies and skippers were frequently seen and easily disturbed. Once in flight they were extremely reluctant to settle. Small Heaths (6+) quickly made a show and seen for the first time this year, with Grizzled Skippers (12+), first of the year Dingy Skippers  (12+), Peacocks (6+), occasional Brimstones and Green-veined Whites, and a single first of the year Small Copper on the half acre transect walk. Common Bee-flies were frequently seen. A Crab Spider  Xysticus, settled amongst the short vegetation. Two more Speckled Woods were seen over the steps from the south leading down to the lower slopes.
Adur Spiders 2020
Adur Skippers

Welted Thistle, Wayfaring Tree
Lower Slopes

Horseshoe Vetch, Hippocrepis comosa, was scattered over the slopes but still only in small patches. I was surprised to see a Welted Thistle on the lower slopes, possibly for the first time ever. Cowslips and Bluebells were flowering south of the Reservoir, but the Daffodils were finished. Blackthorn had receded rapidly down to the last few flowers and was gradually being replaced by the newly flowering Hawthorn. Three large Slow Worms were searched for and found. A Skylark flew overhead and sang.

16 April 2020

Earlier than usual, the first Horseshoe Vetch, Hippocrepis comosa, appeared in flower on the lower slopes of Mill Hill, It was in the middle below the path, amongst the grass and Brambles, not where it is usually seen first. A Fox Spider, Alopecosa, scampered amongst the short grasses. There was a pair of what were probably Grizzled Skippers but these were not confirmed as they did not settle. A Brimstone Butterfly was on patrol, but it was not warm enough for butterflies. The first Milkwort also appeared. Cowslips were flowering on the southern top part of Mill Hill.
Dandelions on Mill Hill
Adur Spiders 2020

9 April 2020


An adult Common Lizard skitted over the short vegetation on the lower slopes of Mill Hill. On a hazy sunny very early afternoon, it was shirt sleeves weather reaching an air temperature of 20°C at 2:00 pm. Wayfaring Tree was flowering by the first bend in the path after descending the southern steps to the lower slopes. The scattered white blossom was the Blackthorn on the top and amongst the scrub.
Adur Thorn

Dog Violets

A Common Bee-fly visited the Dog Violets were scattered over the lower slopes, the land now dried after the recent dry weather. There were a few butterflies; a patrolling Brimstone and a few restless Peacocks.

28 March 2020

The upper car park is closed

23 March 2020

Sweet Violets

Sweet Violets were scattered over the lower slopes of Mill Hill, the land now dried after the weekend sunshine. Even the steps at the southern end were no longer muddy, where I immediately spotted a Brimstone Butterfly fluttering around.  In the very early afternoon a Peacock Butterfly flew energetically over the slopes below the path. On the southern top part of Mill Hill I found the same Adder as before but this was the only reptile. The main stands of Blackthorn were not yet blossoming, but there was one tree in full blossom at the top of the wooded slope. (The sepals were inspected to confirm the ID.)
Adur Thorn
Adur Violets

16 March 2020
After five months isolation from Mill Hill because of inclement weather, the sun finally came out on the muddy southern top part of Mill Hill Nature Reserve. And with the sun came my first butterflies of the year: at least two strong-flying Brimstone Butterflies skirting the still bare scrub, and secondly a Peacock Butterfly first spotted on a drain cover south of the Reservoir. I was most pleased to spot two Small Tortoiseshells fluttering over the thoroughly mown meadow (a good job) north of the upper car park.

Adder, Common LIzard
Slow Worm

Two large Slow Worms, a small slim Adder and a Common LIzard were all firsts of the year reptiles amongst some old logs deliberately placed on the southern part of Mill Hill. Small birds sang to each other from deep inside the bushes but they were mostly too well hidden for me to identify, although I recognised a pair of Blue Tits. A male Pheasant was not so easy to spot into the low light of the early afternoon. Clumps of Daffodils flowered on the southern part of Mill Hill. Green Alkanet was also seen in flower south of the Reservoir. In the top copse, the first flowers and leaves were seen amongst the budding Blackthorn.
Adur Thorn

12 March 2020

Adder on Mill Hill
Report & Photograph by Sean Stones

Autumn mowing at the top of Mill Hill meant that the grass was very short and this Adder moving around was easier to spot than it might otherwise have been.

Report by Sean Stones on Mill Hill Nature Reserve facebook

Mill Hill Bye-laws

Bringing into, or permitting to remain within the Reserve, any dog, unless it is kept on a lead or effectively restrained from worrying or disturbing any animal or bird or from entering any water trough


Mill Hill Wildlife Reports 2018 (Link)
Mill Hill Wildlife Reports 2017 (Link)
Mill Hill Wildlife Reports 2016 (Link)
Mill Hill Wildlife Reports 2015 (Link)
Mill Hill Wildlife Reports 2014 (Link)
Mill Hill Wildlife Reports 2013 (Link)
Mill Hill Wildlife Reports 2012 (Link)
Mill Hill Wildlife Reports 2011 (Link)

Adur Valley & Downs on facebook

Identification of Grasses (Link)
Mill Hill Grasses

A Nature Reserve is defined in Section 15 of the National Parks and Access to the Countryside Act 1949, as land managed for the purpose:

(a) of providing, under suitable conditions and control, special opportunities for the study of, and research into, matters relating to the flora and fauna of Great Britain and the physical conditions in which they live, and for the study of geological and physiographical features of special interest in the area; or
(b) of preserving flora, fauna, or geological or physiographical features of special interest in the area; or for both these purposes.

(Estimated numbers for Mill Hill Nature Reserve only are in brackets)

Chalkhill Blue (3000 +)
Adonis Blue (50 -100)
Dingy Skipper  (75)
Small Heath (250)
Wall Brown  (12)
Meadow Brown  (300)
Marbled White  (50)
Gatekeeper    (200)
Speckled Wood  (>50)
Green-veined White (2+)
Common Blue  (>4000+)
Small Blue       (5)
Brimstone        (8)
Small Skipper   (>50)
Large Skipper   (10+)
Grizzled Skipper  (20)
Brown Argus   (>30)
Green Hairstreak ( a few)

The other species may breed on Mill Hill, but there main breeding area will be adjoining fields or slightly further away. e.g. Small Blue (included above), Small Copper, Small Tortoiseshell, Green-veined White, Peacock, Ringlet, Small White, Large White, Comma, Holly Blue, Orange Tip. (=10). There are huge variances each year for most species.

The following are immigrants &/or hibernators:  Red Admiral, Painted Lady, Clouded Yellow.

The following have not been positively identified (because of ID difficulties):  Essex Skipper. This species is now included for a local field on the Adur Levels within 500 metres of Mill Hill.


The following was confirmed only in 2009: Green Hairstreak.

The following was confirmed only in 2014: Dark Green Fritillary

The next one is no longer found on Mill Hill but were there in the distant (1947) past: Grayling.
The next one has been recorded near Mill Hill in the middle distance past:  White-letter Hairstreak


The Silver-spotted Skipper does not appear to ever have occurred on Mill Hill. PS: There have been recent records.
The Silver-studded Blue has never been recorded from Mill Hill

The Short-tailed Blue was recorded as a single immigrant in 1956.

17 August 2009
A possible (unconfirmed) Brown Hairstreak Butterfly was spotted. A confirmed one was spotted nearby.

Brown Hairstreak and Silver-spotted Skipper have been confirmed from Mill Hill. The first is notoriously difficult to spot and was probably already there. The skipper may be a new addition, but it is small and not easy to spot, and there have now been numerous sightings

Adur Butterfly Page


History of Mill Hill

Aerial Map
Lower Adur Levels (MultiMap) including Lancing Clump and Mill Hill

Horseshoe Vetch, Hippocrepis comosa
First Draft of the Article for the Shoreham Society Newsletter

Link to the            Adur 2012 Nature Notes pagesLink to the Adur Nature Notes 2011            web pages

Link to            the Adur 2010 Nature Notes pagesLink to the Adur Nature Notes 2009            web pagesLink to the            Adur Nature Notes 2008 web pagesLink to the Adur Nature Notes 2007            web pages
Link to Adur            Valley Nature Notes 2003Link to the Adur Nature Notes            2004 Index pageLink to Adur Nature Notes 2005 Index pageLink to the Adur Nature Notes 2006            web pages