Plants of Ancient Downland
indicators on the lower slopes include Dropwort,
Ladies Tresses (upper plateau), Hairy
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,
Thistle, Dwarf Thistle, Squinancywort,
Flax, Small Scabious,
Basil. There are other more widespread
wild plants like the Mouse-eared Hawkweed,
Rough Hawkbit, Lesser Hawkbit, Bird's Foot Trefoil, Ground
Speedwell, Field Speedwell, Sweet Violet,
and Yellow Wort.
Wild Flora and Fauna on Chalk flickr
Adur Wild Flowers 2009
A large part (724 acres) of the downs including Mill Hill were presented to the people of Shoreham in 1937.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.
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
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
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
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
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.
Footpaths at Mill Hill
18 December 2021
ilex - Holm Evergreen Oak Tree
Upper Mill Hill
2 November 2021
Mill Hill from the south
A rambler reported a bright yellow Clouded Yellow Butterfly over the top southern part of Mill Hill. The dead vegetation on the upper meadows had been forage harvested since my last visit, but the dried grasses in the image below remained. I heard the whirring of a Pheasant taking off from the pasture to the east.
22 October 2021
Kestrel over Mill
Photograph by Ken Sillence
9 October 2021
Plateau at the upper part of Mill Hill
A Comma Butterfly visited blackberries at the top of the southern steps to the lower slopes where two Clouded Yellow Butterflies chased each other over a large area. Other butterflies were occasional Meadow Browns, a worn and damaged Adonis Blue, occasional Common Blues, a few Whites, and a few Small Heaths. A Common Lizard skitted across the winding path.
A Clouded Yellow Butterfly flew restlessly over the upper part of Mill Hill searching for nectar amongst the paucity of flowers.
16 September 2021
Hawthorn on Mill Hill
6 September 2021
Bit Scabious, Buddleia
Blue, Carline Thistle
Scores of House Martins flew to and fro over Mill Hill prior to emigration. A trek to the lower slopes was curtailed because of excessive warmth and humidity. Devil's Bit Scabious was seen flowering at the northern end. The usual gamut of butterflies included 40+ Meadow Browns, 12+ Adonis Blues, 8+ Chalkhill Blues, occasional Common Blues, frequent Whites, frequent Small Heaths, at least one each of Clouded Yellow, Brown Argus, Painted Lady (2), Red Admiral.
26 August 2021
Adonis Blue on Carline Thistle
A Kestrel hovered over Mill Hill until after a few minutes a dog appeared and it flew off. Scores of butterflies were disturbed over the lower slopes and for a few minutes when the sun shined in the afternoon this rose to nearly two hundred: 80+ Meadow Browns, 30+ Adonis Blues, 25+ Chalkhill Blues, occasional Common Blues, a few Large Whites, Small Heaths, at least one each of Clouded Yellow, Small Copper, Brown Argus and Treble-bar and Carpet Moths.
Meadow Vetchling, Ploughman's Spikenard, Lesser Knapweed
Ten species of butterfly were seen on the top of Mill Hill on a black cloudy afternoon: frequent Meadow Browns, occasional Common Blues, three Chalkhill Blues, a few Large Whites, Red Admirals, at least one each of Peacock Butterfly, Wall Brown, Painted Lady, a pair of Small Tortoiseshells and a Small White.
16 August 2021
Blue with Basil,
and breezy, an afternoon visit to the lower
slopes of Mill Hill was greeted by my first of the year and an extremely
bright Clouded Yellow Butterfly
sparring with the first of 35+ Chalkhill
of the butterflies on my half transect
were resting and needed to be disturbed to be seen. 100+ Meadow
at least three of the second brood male Adonis
at least two of Peacock Butterflies,
Wall Browns, one each of a good condition
Lady, Large White
and a Small Heath,
were seen in under an hour. On the southern steps, (where the Sloe
had turned dark) there were at least two
Woods. Add more Common
and mating amongst the long grasses on the top part of Mill Hill south
of the Reservoir plus Red Admirals
around the Buddleia.
Both the Kite-tailed Robberfly, Tolmerus atricapillus and the Hornet Robber Fly, Asilus crabroniformis skulked on the paths. Carpet Moths were disturbed. A Common Lizard skitted across the southern steps.
Notable flora included Ploughman's Spikenard, Carline Thistle, Wild Mignonette, and one spike of Autumnal Hawkbit (ID checked) with the more prevalent Lesser Hawkbit and Rough Hawkbit. And large patches of Hawkweed Ox-tonque on the lower slopes was new. Pineapple Weed was present by the gates of the southern car park.
Late in the afternoon, a brief visit to the top of Mill Hill hosted frequent Meadow Browns, Common Blues, Red Admirals, and occasional Peacock Butterflies and Small Tortoiseshells.
Rain stopped play again in the afternoon, but not before I counted 40 restless male Chalkhill Blues on a quarter transect of the lower slopes of Mill Hill, plus a notable 20+ Peacock Butterflies attracted to the Buddleia in flower with a few Red Admirals and Painted Ladies and the usual gamut of Gatekeepers, Meadow Browns, Brimstones, Common Blues. Large Whites and 6-spotted Burnet Moths.
the afternoon sun, out came the butterflies
on the top of Mill Hill.
male Chalkhill Blues
was impressed by the scores of Round-headed
on the plateau south of the upper car park. Numbers were in the low
hundreds. The small umbellifer Burnet
Saxifrage and the Small
Scabious were also noted.
small amounts of Restharrow,
Mignonette and Yellow
3 August 2021
fluttered over the lower slopes of Mill Hill under a cloudy sky in the
afternoon. Frequent 25+ Gatekeepers,
25+ Meadow Browns,
30+ Chalkhill Blues,
including a mating pair,
were joined by occasional Large Whites
and at least one each of a Marbled White,
female Common Blue,
Peacock, and Small
Shell Moths and
Burnet Moths were seen. A Kite-tailed
Robberfly, Tolmerus atricapillus,
waited in ambush. There was one large brown
caterpillar crawling over the path. On
the top part south of the reservoir, I added a Brimstone
Butterfly. Painted Lady and Small
2 August 2021
Fleabane, Wild Parsnip, Dwarf Thistle
Lower Slopes of Mill Hill
a rain sodden and cloudy week, moderate rain curtailed my visit to Mill
Hill before any resting butterflies
were disturbed on the lower slopes. Dwarf
Thistle was common. The first shoots of
Thistle were seen. House
Martins flew over the downs.
At last, a handful of male Chalkhill Blue Butterflies fluttered restlessly over the lower slopes of Mill Hill.
Large White on Bristly
Ox-tongue, Lesser Centaury
(very small flowers) with Eyebright.
19 July 2021
on Perforate St. John's Wort, Wild Basil
Round-headed Rampion, Dwarf Thistle
the lower slopes in the sunshine where there were frequent butterflies:
Browns, Marbled Whites. Large Whites,
Skippers, a Red
Small Heath, but no Chalkhill
Notable flowers were hundreds of Wild Basil, frequent Round-headed Rampion, frequent Small Scabious, Common Centaury, Dwarf Thistle and Perforate St. John's Wort, Lesser Hawkbit.
On a virtually cloudless day the sun (25º C) burned anybody who ventured out of the shade. I still visited the upper part of Mill Hill in the mid-afternoon where two dozen butterflies fluttered around the attractive selection of chalkhill flowers amongst the long grasses south and west of the top car park. Marbled Whites. Large Whites, and Meadow Browns were all restless. There was at least one Small Heath, a probable Wall Brown and my first Painted Lady of the year on the middle slopes south of the copse,
Round-headed Rampion, Small Scabious, Pyramidal Orchid
Notable flowers were frequent and more than usual Round-headed Rampion, frequent Small Scabious, and Greater Knapweed on the exposed top of the hill. On the sheltered middle slopes the notables were Melilot, Lady's Bedstraw, Marjoram, and Field Scabious.
14 July 2021
Marjoram, Centaury. Squinancywort, Dwarf Thistle
A couple of Gatekeepers on the southern steps to the lower slopes were the first of the year, Other butterflies were occasional Marbled Whites. Large Whites, Meadow Browns, Red Admirals, a few Small Skippers, Small Heaths and one Wall Brown.
Marbled White Butterflies were very lively over the lower slopes of Mill Hill where I also spotted my first Small Skipper of the year. New flowers appeared on a cloudy humid afternoon. Small Heath Butterflies, pristine Red Admirals, large Meadow Browns, a Silver Y Moth and a 6-spotted Burnet Moth were noted as the first spots of rain were felt.
A Great Green Bush Cricket, Tettigonia viridissima, was spotted on the southern top part of Mill Hill for the first time.
Adur Crickets and Grasshoppers
Knapweed (white) and
Southern top part of Mill Hill
A Buzzard soared over a sunny (19°C) Mill Hill in the early afternoon. Butterflies were lively and frequent: Common Blues, Dingy Skippers, Small Heath Butterflies, Brimstones and Silver Y Moths over the lower slopes. A Holly Blue fluttered by the hedge by the southern car park to Mill Hill.
Butterflies fluttered over the sun-drenched (21°C) lower slopes of Mill Hill: 30+ male Common Blues, 4+ male Adonis Blues, frequent Dingy Skippers and Grizzled Skippers, my first Brown Argus and Cinnabar Mothof the year, frequent Brimstones, a few Small Heath Butterflies and a probable Wall Brown. By the flowering Hawthorn-lined road there was a Holly Blue. All the butterflies were restless.
the southern top of the hill, the first Greater
Bird's Foot Trefoil was seen in flower.
Common Bird's-foot Trefoil Lotus corniculatus is shorter and grows in dry grassland. Its stems are solid whereas the stems of Lotus pedunculatus are hollow.
27 May 2021
Skipper, Round-leaved Cranesbill, Milkwort
Horseshoe Vetch, Adonis Blue Butterfly, Common Blue
The sun shined in the afternoon for the first time in over a week, I was able to confirm my first male Adonis Blue Butterfly of the year with frequent Brimstones but not many other butterflies on the lower slopes of Mill Hill. There were occasional amorous Wall Browns. a few Small Heath Butterflies, a few Dingy Skippers, Grizzled Skippers, and Common Blues (including a dark blue female). At the top of Chanctonbury Drive, there was the flutter of a Holly Blue and some Large Whites. Early Elderflower appeared.
19 May 2021
May Gallery on facebook
Swathes of Horseshoe Vetch, Hippocrepis comosa, covered the lower slopes of Mill Hill on a cloudy afternoon inimical for watching butterflies. In an hour I spotted to my first of the year Small Heath Butterfly and a few first of the year Dingy Skippers, at least three male Common Blues, a Brimstone Butterfly, a few Large Whites and Red Admirals. At the top of Chanctonbury Drive, the flutter of blue was a Holly Blue.
Hawthorn was beginning to flower in the hedgerows. Patches of Crosswort, Cowslips and Germander Speedwell decorated the area south of the Reservoir.
A Buzzard soared overhead mobbed by the frequent Crows. And a rather scruffy Jay put in two appearances.
Five o'clock in the afternoon is a bit late in the day for seeing active butterflies on the lower slopes of Mill Hill as most of them will have gone to roost. I managed to spot my first male Adonis Blue (not confirmed -subsequently thought to be a Common Blue), and my first of the year Small Copper visiting the abundant Horseshoe Vetch, Hippocrepis comosa. A flock of up to a dozen corvids, mostly Jackdaws. were persistently feeding on something amongst the short vegetation on the steeper slopes. A Peacock Butterfly flew down and I disturbed a handful of Grizzled Skippers. Hawthorn was beginning to flower. Cowslips were seen south of the Reservoir.
Cowslips, Dog Violets
Tripping over butterflies at Mill Hill today with a grand total of 14 species recorded. Dozens of Dingy Skipper & Grizzled Skipper, Green-veined White, Small White, Brimstone and a singleton Orange-tip doing the rounds. Wall are coming along nicely with at least half a dozen bobbing around, a female already ovipositing. A handful of Small Copper seeing off all-comers which included my first Common Blue of the year, around 6 males seen. Green Hairstreak also doing well, regularly getting stuck in with the multi species aerial brawls, again about half a dozen active. The afternoon brought out 4 or 5 fresh looking Peacock and like Abbots Wood on Wednesday, there were good numbers of fresh immigrant Red Admirals, a female was seen egg laying (from the state of some they must have come via Jersey!). A single Comma made a very brief appearance (unable to tell if it were an early hutchinsoni or a late hibernator). The day started off with a rare Sussex sight of a female Small Tortoiseshell avidly investigating some nettle on the edge of the horse paddocks on the south side of the Shoreham Bypass.
Horseshoe Vetch, Hippocrepis comosa
I only managed to spot eleven species of butterfly, the last seven on the lower slopes of Mill Hill: Red Admiral, Speckled Wood, Small White, Large White, Green-veined White, Brimstone, Wall Brown, Peacock, Grizzled Skipper, Dingy Skipper, Common Blue. I also noted a few pyralid moths Pyrausta nigrata. Blackthorn had ceased to flower.
Mill Hill Nature Reserve on facebook
22 April 2021
A few Peacock Butterflies visited the battered and frequent Sweet Violets and Dog Violets scattered thinly over the lower slopes of Mill Hill. A bright yellow Brimstone Butterfly fluttered by the Holly Tree, where the Wayfaring Tree had been hacked down by the conservation workers.
ADDERS ON MILL HILL (VIDEO)
by Tegan Newman
15 April 2021
Mill Hill (south)
Hill Wildlife Reports 2020 (Link)
Mill Hill Wildlife Reports 2018 (Link)
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)
Mill Hill Nature Reserve on facebook
of Grasses (Link)
Mill Hill Grasses
Reserve is defined in Section 15 of
the National Parks and Access to the Countryside Act 1949,
as land managed for the purpose:
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
SPECIES OF BUTTERFLIES DEPENDENT ON MILL HILL
(Estimated numbers for Mill Hill Nature Reserve only are in brackets)
Blue (3000 +)
Adonis Blue (50 -100)
Dingy Skipper (75)
Wall Brown (12)
Meadow Brown (300)
|Marbled White (50)
Speckled Wood (>50)
Green-veined White (2+)
Small Blue (5)
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.
following was confirmed only in 2009:
following was confirmed only in 2014: Dark
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
Skipper does not appear to ever have occurred
on Mill Hill
The Silver-studded Blue has never been recorded from Mill Hill
The Short-tailed Blue was recorded as a single immigrant in 1956.
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
History of Mill Hill
Lower Adur Levels (MultiMap) including Lancing Clump and Mill Hill
Vetch, Hippocrepis comosa
First Draft of the Article for the Shoreham Society Newsletter