FOR THE 2004 REPORTS CLICK ON THIS TEXT
on Hippocrepis comosa (Horseshoe Vetch) plus
Message on Hippocrepis comosa
prostrate downland tetraploid race of Hippocrepis
comosa is not harmed by moderately
heavy sheep grazing and is resistant to moderate trampling, but doesn't
persist after ploughing or disturbance of the ground, or in areas grazed
Journal of Ecology Vol. 61, pp. 915-926 (1973).
Identification Notes (Link)
Biodiversity Calcareous Grasslands
Mill Hill (lower slopes) Flora Images (technical)
It was only on a sombre but warm, 12.3 °C mid-afternoon, January that I noticed a couple of small Holly Trees, without berries, on the steep slopes higher than the path that weaves its way through the lower slopes.
Mill Hill 2004 (with new map)
15 December 2003
On the path down to the lower slopes of Mill Hill, a Robin Redbreast put in a seasonal (they are present all the year) appearance. And a solitary thrush dug for worms in the short wet grass. From its pronounced yellow throat-breast colour, I think it was a Song Thrush. Incongruously, it was feeding much more out in the open than was usual for the normally timid Song Thrush. There were a score or more of empty snail shells, more than usual. I saw one solitary small Dog Violet flower, but an absence of any grassland fungi, although in the scrub to the north, one small tree provided home for a common woodland toadstool, possibly the parasitic Honey Fungus, Armillaria.
ID for a Hairy Violet by Michael Lush on UK Botany
Message about this Violet
Buffeted by the breeze, the expected Kestrel hovered over the lower slopes. After 50 mm of rain in the last three days, the grass was green and the paths muddy. The upper part of the lower slopes just below the ridge was thick with rabbit faeces. So thick, that if I wanted to sit down on the short wet swards of tufty grass, it would have near impossible to find a bit that has not been used as a rabbit latrine.
In the afternoon, an unidentified mouse fell out of the Hawthorn bush branches and after a fraction of second to gain its bearings, scampered off into the undergrowth (a patch of bare grey earth underneath the Hawthorn). It looked like a House Mouse to my untrained eye although it seemed about 10% larger with better groomed dark brown-grey fur. It could have been a Yellow-necked or a Wood Mouse? There was little or nothing of special interest: Blackbirds and Robin Redbreasts, but no butterflies. Sheep grazed in the field below the slopes of Mill Hill on the western side.
In the clear morning light I had another distant view of the "bird of prey" I saw a couple of days ago. The light was better and I really now think it is most likely a female Kestrel (which I thought it was in the first place). However, it still was a dark chocolate brown in colour, still seemed about to hover (it stalled in flight rather than hovered), but never did so, and spent part of the time chasing small birds amongst the bushes (which Kestrels do in autumn). The disposition of the tail in flight was Kestrel-like and the light underwing as well.
There were Blue Tits, Blackbirds, Magpies, Pied Wagtails, House Martins clearly noticeable, but no butterflies.
There were a pair of Stonechats amongst the Hawthorn as I looked down from the Mill Hill ridge on to the steep slopes below.
Its caw (call) was a cross between that of a Magpie and a Crow, but it looked more like an overlarge Thrush or Blackbird: a couple of Ring Ouzels, Turdus torquatus, looked a very dirty black with a white/grey breast as they chose Hawthorn bushes ahead of other shelter on the lower slopes of Mill HiIl. According to the Shoreham & District Ornithological Society 1988 "Birds of Shoreham" the peak month for migrating Ring Ouzels is October.
hawk was perched for at least a few minutes
on another Hawthorn
bush that stood out amongst the clump of scrub that forms and extensive
border of Mill Hill with the field on the western side further down in
the Adur valley. I took the opportunity to have a closer look (through
my 9 x 40 binoculars) at this dark brown raptor, partially silhouetted
in front of the low sun, that seemed to have a bulbous
head. Suddenly, it took off and descended Wagtail-like and disturbed
a couple of small birds in the stubble field below. Later, presumably the
same bird, was observed performing a low level glide and wing tilting,
(demonstrating more agility than I have ever seen in a Kestrel),
showing off the white underside with a large amount of dark edging to the
wing-tips, before it landed in another small Hawthorn
at the top of the ridge (my viewpoint was from a clump of turf in the centre
of the path through the Vetch Field (lower slopes).
I have identified this 'bird of prey' as a female
columbarius. (See the note below:
this identification is wrong!) This bird disturbed
the House Martins, so it is possible that these were the intended prey.
The bird seemed as large, if not larger than a Kestrel,
so the other possibility is that it was a female
subbuteo. (The Hobby
is both rarer than the Merlin and
it would have expected to have migrated south a month ago.)
I now think it is probably a Kestrel afterall.(17 October 2003). Observations of a hovering bird on 26 August 2004, now make me convinced that this bird was a Kestrel.
In the scrub, there were plenty of rustlings (as usual), and twice the source was discovered to be foraging Blackbirds. Dozens of House Martins flew to and fro. There were Meadow Pipits and Skylarks as well.
Butterflies were limited to two Red Admirals, one Wall Brown (in the Tor Grass area), and a very tattered Speckled Wood Butterfly in the scrub to the north.
Common Darter Dragonflies, Sympetrum striolatum, were widespread and at least a dozen were noted.
About 25 Common Darter Dragonflies, Sympetrum striolatum, and at least a couple of Migrant Hawkers, Aeshna mixta, were seen on the lower slopes of Mill Hill in the early afternoon. I had not expected more than an occasional butterfly, but there were at least two Wall Browns clearly seen - they must be the third brood - as well as two Meadow Browns with a female that settled, two unidentified white butterflies, as well as one strong flying Clouded Yellow Butterfly and there could have been two of them.
Still the summer lingers on, but the temperature of 17.1 ºC on a sunny day falls below 20 ºC, as expected in the final quarter of the year.
Fresh Wall Brown Butterflies some put in an appearance on the path down to the lower slopes of Mill Hill. They were still very flighty and would not settle long enough for a photograph. The small moth-like brown flying insects were discovered to be small female Common Blue Butterflies and there were larger male Common Blues as well, seeming much bluer in flight than when they settled (but not as bright as Adonis Blues, but I checked just to make sure*). One Small Heath settled with its wings closed and then a handful of Meadow Brown Butterflies were identified, not so easy with the first one that disappeared into the Brambles. By the stile that leads on to the overgrazed land, three Clouded Yellow Butterflies danced around each other, and I was pleased to see a large party of ramblers on this footpath which is so often blocked by cows. The return journey produced a Red Admiral Butterfly and a Large White followed by a Small White Butterfly.
Adur Butterflies Flight Times
From the Privet and Bramble patch in the lower centre, a blue male Emperor Dragonfly rose suddenly, and there were a handful of dull brown Common Darter Dragonflies.
(* Subsequent identifications in 2004 revealed that it is very easy to identify worn Adonis Blues as Common Blues. The former butterfly is slightly commoner than the Common Blue on the lower slopes.)
A mating pair, the dark blue male Southern Hawker Dragonfly* in tandem with the emerald green female, was a magnificent sight as they flew rapidly up the lower slopes of Mill Hill and quickly disappeared. The scores of House Martins all seemed to be flying from west and east up from the Adur valley on to the downs to the north of Shoreham. There were a handful of Common Darter Dragonflies as well. (*This was originally identifed as an Emperor Dragonfly but the ID has been changed.)
Late in the season, but on an exceptionally warm day for September at 21.8 ºC, the numbers and varieties of butterflies was expected to be small in order of first seen was a Wall Brown (4+), Large Whites (6+), Meadow Browns (15+), Small Heaths (8+), small Common Blues (12+) and one Red Admiral. There was a possibility of a couple of Adonis Blues in the northern part of the slopes, but these could not be confirmed.
7 September 2003
Just one female blue butterfly was spotted briefly with a plain chocolate brown upper wing, but I still cannot be sure if it was an Adonis Blue or a Chalkhill Blue, despite managing a photograph shown on the left. (Even if I had a butterfly net, I might have left it at home on an unpromising time of the year for butterflies). The butterfly on the Carline Thistle in the photograph below (second from the left, click on the image to enlarge and view the butterfly) is probably the same species. A half a dozen Meadow Brown Butterflies were identified on the lower slopes as well as at least one unidentified (to species level) Cabbage White Butterfly.
Blue Butterflies of Shoreham
Adur Butterflies Flight Times
On the Saturday of Shoreham Air Show, Mill Hill was closed to cars so there was only about a hundred people on the hill at one time, and apart from a couple of blackberriers, and one dog walker, the parched lower slopes were empty. The first blue was the bright blue of the Common Blue Butterfly, but the Adonis Blues soon appeared and the final count was 25. It was easy to get the species mixed up as the female blues that had orange spots on the upper hindwing (see the photograph on the right) were Chalkhill Blues. There was at least a pair of Chalkhill Blues in pristine condition, but all three species of blues were about in the same numbers, but Common Blues and Chalkhill Blues were mostly worn and battered, with one third females.
puzzle was a brown butterfly that looked exactly like a Brown
Argus. There was no hint of white roundels
on the upper wing and was just like the specimen seen and photographed
on 23 July 2003 with orange spots neatly
arranged on both the upper wings. There just a hint of blue colour, if
anything less than shown in the photograph on the earlier date (click
on this text). (Alas this butterfly flew off when disturbed by what
looked like a larger female Chalkhill
PS: Brown Argus Butterflies were discovered and confirmed in August 2004.
Yellow Butterfly flew from north to south
late in the afternoon. Meadow
Butterflies, including many large females,
and Small Heath Butterflies
were very frequently seen, with numbers of both exceeding fifty. A few
Whites fluttered past rapidly.
A male Common Darter Dragonfly buzzed over.
Although overcast, I was disappointed to count only twelve Adonis Blue Butterflies. Chalkhill Blues were more numerous at thirty and probably many more, Meadows Browns were noticeable, possibly fifty plus, Small Heaths, sixty plus, a single Clouded Yellow and a handful of Small Whites.
20 August 2003
one static spot there would be 30 to 50 butterflies within a radius of
two metres. Mostly Chalkhill Blues,
but Common Blues,
and a handful each of Painted Ladies,
Whites. The blue
with brown on their wings were males as they chased the females. All the
butterflies were more flighty and restless than when it was cooler. I looked
until I found a Small Heath Butterfly
in the short grasses. This small butterfly does not open its wings but
aligns its body at an acute angle and is now easily recognised. This may
be one from the second brood which is not due until August.
On an overcast, cool, with brief sunny spells, light rain at times, it would be thought of as unpromising day for butterflies. However, the whole of the lower slopes of Mill Hill were alive with the amorous flutterings of an estimated 2,000 + Chalkhill Blue Butterflies reaching densities of three every square metre (two males and one female) on plenty of occasions. On my restricted transect the count came to 250 (within two metres each side of me, partly estimated* as there were so many). The lower slopes cover nearly five acres of ground so the guesstimate is a conservative one. This year, the numbers must approach the historic records of thousands of Chalkhill Blues reported in the past. Some (50+) specimens were halfway between the colours of each sex, i.e. predominately blue, with a substantial brown tinge. (* Subsequent counts have indicated a probable underestimate.)
Only 200+ Chalkhill Blues on the lower slopes of Mill Hill, an appreciable fall from the abundance of yesterday. A Wall Brown was also a first from the lower slopes nectaring (not often seen with this butterfly) on Stemless Thistle and other flowers. At a rough estimate there seemed to be about three Chalkhill males to each female. On some of the females the upper wing orange spots were very clear which is not always the case on Mill Hill. The very bright blue was the odd Common Blue Butterfly. The possible discovery of a Brown Argus Butterfly was rejected as more likely to be a female Common Blue. A Brown Argus was discovered on the Slonk Hill southern embankment but even this one is not 100% certain (picture below on the right).
Identification Notes about the Brown Argus
Chalkhill Blues compared
July 2003 on the left with the orange spots (ab. postaurantiaextensa?) and August 2001 on the centre from the upper slopes
The image on the extreme right is the Brown Argus
For comparative female Common Blue image, click on this text
Variations of Chalkhill Blues (Cockayne)
I returned to Mill Hill in the early evening and I was surprised that on the lower slopes, the abundance of Chalkhill Blues seen at midday was simply not on view any more. There were still plenty of Chalkhill Blues around but I only counted about thirty and most of them were hiding and only rose into flight because I disturbed them. (Do the Chalkhill Blues on the lower slopes disperse quickly to find longer grasses for roosting and nectar plants?) On the approaches to the Vetch Trail from the south a handful of Wall Browns left the chalk path and half a dozen 6-spotted Burnet Moths buzzed around the Knapweeds.
There were a couple of Magpies and Jackdaws searching the slopes for food.
Over 300 Chalkhill Blue Butterflies were observed fluttering around and copulating on the lower slopes of Mill Hill and they were to be seen on the sunny day at a conservative average of one butterfly every two square metres. At this prevalence, I got the impression that I was constantly about to step on one.
Over the five acres (the area was measured later at 6.4 acres) of the lower slopes this would give a figure of 2,500 butterflies, and the 25 acres of upper slopes would have supported hundreds as well. On reflection this number is an overestimate as the Chalkhill Blues were not evenly distributed. It would be fairer to say this was the density for an area of about one acre and four acres were only at about one per four square metres (conservative estimate veering on the low side) plus another minimum of 200 on the other slopes. So I arrive at a number count of 1,200 Chalkhill Blues. This is near the peak number for this emergence as over the next few days the butterflies disperse to looks for better nectar sources and roosting sites in the longer grasses. The concentration of butterflies is near the bramble bushes at the bottom of the slope.
Phil Weller reported Marbled Whites from the long grass on the ridge. The lower slopes supported Meadow Browns (50+), Gatekeepers (30+), and Small Heaths (only one identified positively).
The grass and herbs still remained very short like a rough lawn, and the lack of tall grasses meant that the Round-headed Rampion was only occasional and the nectar source, the Greater Knapweed was only in small clumps. Clustered Bellflower, Campanula glomeratum, was discovered in a small patch at the southern end of the lower slopes near where the pathwinds its way around the Wayfaring Tree.Nectar sources, except in the hedges were exiguous.
Butterfly List (Full Report)
Chalkhill Blues Conservation Advice
Butterfly Transect Method
Moving Images (CD-ROM only)
Chalkhill Blue Butterflies on the Waterworks Road, Old Shoreham numbered at least five and they could be seen immediately, on the margins amongst the ferns, just north of where the road passed under the A27 Flyover. There is a distance of 700 metres from the breeding areas (Vetch Trail) of the Chalkhill Blue with a full grown Sycamore, Hawthorn and Ash wood in the intervening space. The butterflies flew against a breeze from the south.
14 June 2003
By the stile on the border of Mill Hill public land (area overgrown with scrubbery) and the Old Erringham grazing land (TQ 207 076), a sleek slate blue-grey raptor flew in a silent gliding arc on my arrival, and then disappeared. I was looking down on the bird of prey from above, a rather unusual viewpoint and I noticed the streamlining of the tail feathers very clearly. My first thoughts were Sparrowhawk, but this bird seemed to have a different flight pattern and seemed slightly larger than the male Sparrowhawk. This bird could be the rare Hobby, Falco subbuteo. Estimates of the British summer population of this bird could be only 500 breeding pairs. (I hope that is not a Kestrel, both looking and behaving oddly!?) (2005: Later observations of an agile Sparrowhawk in this area, really points to this hawk as being favourite.)
the Vetch Trail the absence of the vast yellow expanses of Horseshoe
Vetch was my instant impression. The grasses
were still the short springy turf and quickly a blue
butterfly fluttered by.
It was an oldish Adonis Blue Butterfly and I only counted three in an small area, compared to 20+ Small Heath Butterflies, a few Small Tortoiseshells and some Small Skippers (at least two weeks and possibly a month early: after considerable thought it is unlikely that they were misidentified). (PS: The obvious ID would be Large Skippers.)
The Horseshoe Vetch flowers have diminished. I did not venture down to the lower slopes, but on the rabbit-warrened steep slopes with the springy turf, beneath the ridge, the only butterflies seen to be in flight in the early evening were a handful of orange (upper wing) Small Heath Butterflies.
The Adonis Blue Butterflies have disappeared from the lower slopes of Mill Hill and the vast expanse of Horseshoe Vetch has now receded.
A yellow flower covering of the meadows was dramatic. In the foreground on the ungrazed slopes, the dominant plant was Horseshoe Vetch, although a few Cowslips were present. However, in the far field which has been grazed heavily by both sheep and cows the dominant yellow is from the Bulbous Buttercup to the exclusion of other flowers.
A walk on lower slopes of Mill Hill this morning through the Horseshoe Vetch meadow brought sightings of about 30 Adonis Blue Butterflies with five Cinnabar Moths and Small Heath Butterflies with five Blue Damselflies as well.
On the Mill Hill lower slopes (Vetch Trail) the following butterflies were spotted in order of conspicuity:
Blue 50+ (mostly males observed)
(counted, some could have been counted twice)
Brimstone x 2
Peacock x 2
Small Copper 4+ (my first record from Mill Hill)
Small Heath 6+
Dingy Skipper 12+
Grizzled Skipper 3+
Speckled Wood one (in the scrub)
was just one Cinnabar Moth spotted
amongst other day-flying moths, in the expanse of
Horseshoe Vetch and other plants in flower
including a few Cowslips
(mostly blue, some were purple: I am not sure which species?). All the
plant species are indicative of a classic chalkhill meadow. The Carline
Thistle is an unusual plant of the chalk with the leaves dying
in the spring.
On the lower Horseshoe Vetch covered slopes visited yesterday. A few Small White Butterflies were conspicuous but it was the other butterflies that proved to be of interest.
footpath winds its way through the yellow Horseshoe Vetch (just beginning
Viewpoint from the south
The lower field is meadow. The fields to the north near Old Erringham are pasture.
Put the cursor over the above image for the butterfly locations
were many more blue butterflies
around, at least 30 seen, some flirting and others chasing different species
off the Horseshoe Vetch
flowers. I still have these down as Adonis
The possibility of Common Blue Butterflies as well was not ruled out, but unlikely.
Blue Butterflies Identification page
Conservative numbers of the other butterflies actually seen on the lower slopes were as follows:
Dingy Skipper 15+
Small Heath 15+
Orange Tip one (my first record from Mill Hill)
Wall Brown 4+ (on the paths between the scrub near the Triangle)
Cinnabar Moth one
Pyrausta nigrata Moth several
I followed the Vetch Trail on the lower slopes of Mill Hill towards Old Erringham on a sunny May Bank Holiday Monday. Several acres of the steep slopes were graced by the yellow flowers of the Horseshoe Vetch (the food plant of the Chalkhill Blue and other butterflies.) Wild Privet threatens to incurse.
vivid blue colouring of just the one Adonis
Blue Butterfly was startling as it chased
away a Small Heath Butterfly
from the flower of a Horseshoe Vetch. The
underside wing of the Adonis
was heavily pigmented with brown. The Small
Heaths settled with their wings closed, but
it seemed that were about to open them, but they never did. The Painted
Lady was a battered specimen with parts
of its wing missing.
The Dingy Skippers with at least 25 scattered over a wide area were the commonest butterflies in flight, but I saw a handful of Grizzled Skippers and the red of the single Cinnabar Moth was most striking when it fluttered around just above the rabbit-cropped plants.
were Speckled Wood Butterflies
and there was one Red Admiral
that followed me in the dense scrub incline or several of them.
(26 May 2003)
Lower Slopes: Extra Images
Mill Hill 2004 (with new map)