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The Butterflies of Essex
2024 Year in Review

Holly Blue Celastrina argiolus

Summary
Holly Blue is of Least Concern in the vice-counties of North and South Essex, and is considered the lowest priority when it comes to butterfly conservation. It is considered to be widespread throughout Essex, and is locally common within suitable habitat, although it undergoes large fluctuations in abundance from year to year in Essex, just like most other places in the UK. It occurs wherever there is plentiful Ivy Hedera helix and Holly Ilex aquifolium in partial to full sun, including woodland edge, rides, glades and other clearings. It is also a frequent occupier of parks and is a common visitor to gardens, two habitats that I enjoy their presence with a small colony established in my own garden for a few years. It has spread further north and eastward and recently seems to have greater abundance in the north-east of Essex, or at least higher recorded sightings. Holly Blue is the 13th species in my list of recorded sightings during 2024 with a total of 388. iRecord sighting records provide spatial and temporal distribution for the whole of the UK which suggests that the Holly Blue can be seen in nearly every hectad in Essex. The temporal distribution for the last 3 years also shows how much of a boom year 2023 was, with a reduced abundance recorded during 2024 lower than 2022:
A more localised analysis of recorded sighting spatial distribution is provided by looking at the Essex Field Club hectad distribution map which shows that they are most common towards the south-west of the county and north-east London. Most of the areas where sighting records are missing are low population density agricultural land on nutrient-rich soil towards the north-west of the county. The Dengie Peninusla and Foulness Island in the south-east along the Essex Saltmarsh Coast lack woodland and larval food sources:
The spatial distribution map for all sightings recorded on the iRecord website since 1984 is not so complete due to data collection methods only beginning to change to digital within Essex from about 2021. But it allows us to look at local trends and can be used as a baseline moving forward:
It does show that the highest densities of recorded sightings of Holly Blue were in the woodland habitats of Epping Forest, the South Essex woodlands, and the wooded areas in the River Roman SSSI, such as Friday Wood, as well as near me in mid-Essex in woods of the Danbury Ridge nature reserves.

A comparison of the spatial distribution maps of the boom and bust years of the last two years shows the following:
They both show similar higher densities of recorded sightings within the previously mentioned areas but there is a slight drop in densities over the whole of the vice-counties of North & South Essex.

The change in abundance of the Holly Blue during 2023 and 2024 is much more significant with a drop in occurence throughout the areas indicated above.
The above graphs show that recorded sightings were greater throughout the whole of 2023 compared to those recorded during 2024. The most significant difference is the drop in numbers of recorded sightings during the second brood of 2024 with a very poor occurence. This shows up more clearly with the temporal distribution graphs of abundance by month:
The graphs show a huge drop in recorded sighting abundance during June and July with an even higher drop of around 2/3rds during August 2024 compared to 2023. I certainly found that to be the case from my own experience of the species with Holly Blue occurrence being a surprise rather than something that was to be expected in suitable habitat.

As the locations are very similar, it might interest you to see where the recorded sightings occured with, for me at least, the most surprising site being RSPB Rainham Marshes:
I would suggest the sites with the highest totals are those with regular transects which occur on a weekly basis and do not reflect the actual numbers of individuals with double-counting occurring which I have found to be the case with my own transect (see below).

My own data does not reveal the experience I had of the Holly Blue during 2024. I noticed a massive difference between seeing Holly Blue on a regular basis and good numbers at any particular time during 2023, to seeing Holly Blue on an irregular basis with ones and twos the normal. My own little colony was very disappointing but this does not show up in the totals of recorded sightings - they were the same individuals seen on multiple occasions.
The above map shows the few sites that I came across Holly Blue with the highest density of recorded sightings being within Chelmsford and mid-Essex - mostly local as shown by the Abundance by Site table below:
These figures are just not accurate from my own observations. As I suggested above for all recorded sightings in Essex and North London limited to those on iRecord which contains all transect data, there are multiple sighting records for the same individuals. There was no way there were 68 Holly Blue in my local park or 50 in my own garden. I did not see more than 5 at any one time in my garden - there were no more than 10 over the whole season but they were counted weekly on a transect [which is one of the reasons I have dropped walking a transect]. I am more interested in totals of individual butterflies wherever I visit and make every attempt not to double count as well as other considerations to avoid errors and obtain a more accurate and precise data set. Data errors for Holly Blue are stark and more significant than most species. I would expect this to be the case for all recorded sightings. Unlike a lot of species, such as the Hairstreaks which are under-recorded, I think Holly Blue is over-recorded.

242 of my 388 recorded sightings occurred in Chelmsford which is a massive over-recording skewed by my transect data. Locally Holly Blue occur in good numbers with plenty of Hedera helix and Ilex aquifolium and I would regard it as common but not to the extent my recorded sightings would suggest.
My data for temporal distribution over the two broods show similar trends as the data sets for all recorded sightings on the iRecord website. I did not feel like I experienced a second brood - I am surprised I recorded 49 in August.

Highlights
I experienced more sadness than joy when it came to Holly Blue. I was particularly upset in the reduced numbers of my garden colony hoping they recover sufficiently to survive into 2025. It was good to see them fluttering around the ivy laden boundaries of the local park but Holly Blue Alley was quiet compared to the amazing numbers I came across during 2023 when I named the walkway through an extended ivy arch. I must add that there was a ridiculously large number of recorded sightings along a similar walkway near Holland-on-Sea with 100 plus seen on a single visit and large numbers continuing for some time. I am not sure these recorded sightings have been certified by the Essex Recorder yet to appear on the completed data set for the vice-counties of North & South Essex. Those figures as well as others for the north-east of Essex from Frinton-on-Sea to the Naze peninsula must be the highlight - one that I did not experience.

March 2025

March had warm temperatures but the 'feel like' temperature was a lot lower due to chilly, Arctic north-easterly winds. This caused a cold spell between two periods of warmer weather when the butterflies started to take to flight. The end of March was particularly good and even brought out early Speckled Wood, Holly Blue, and the smaller Whites started to emerge too. March was a month full of Peacock, Comma, and in some places, Brimstone which all topped 100, with Peacock topping 200 and Comma 150 plus.
I managed to see Large White and Green-veined White within March and the Speckled Wood sighting came on the last day of the month. Unlike elsewhere in the country, Red Admiral numbers were down and only started appearing during the latter warm period towards the end of the month. The most disappointing result was the low numbers of Small Tortoiseshell which was even lower than I hoped for with a conservative estimate. To not record 20 sightings of Small Tortoiseshell is alarming especially the very low numbers here in the floodplain of the River Chelmer.

Unlike some others, I missed out on Small White, Orange-tip, and Holly Blue, although Small White was seen on the 01st of April. In terms of numbers, 545 recorded sightings of 8 species during March is quite good, and hopefully will continue into April.
My first sighting of 2025 was a local Peacock in Meadgate Fields Open Space on the 04th of March with a trip to Hatfield Forest on the 06th being the only highlight during the first week - an amazing 50 Brimstone out of 70 recorded sightings with a pair in cop being the standout, probably for the month in fact. The year didn't really get going until the 20th of March with 100 recorded sightings reached on the last day of the month. Peacock began to come out during this period and started to top the list of species seen during the site visits throughout the county.
Hatfield Forest was by far the site with the highest recorded sightings with a superb 201 over three visits. Belton Hills NR snuck in during the last days of the month. Locally Lingwood Common was active but everywhere else locally was relatively quiet, especially the aforementioned lack of Small Tortoiseshell. Langdon Hills Country Park, which includes One Tree Hill [Hawksbury Bush, Johnson's Meadows, & Martinhole Wood], Northlands Wood, Willow Park, & Marks Hill Wood Nature Reserve, has not really started yet with a total of 62 recorded sightings. The Benfleet Downs, Hadleigh Castle Country Park, & Belton Hills Nature Reserve walk produced 96 recorded sightings in comparison. The three best butterflying sites in Essex are starting to appear within the data, these being:

Hatfield Forest [including Wall Wood] 213
Benfleet Downs to Belton Hills NR 96
Langdon Hills Country Park 62

Notable absences so far are the North Essex sites of EWT Great Holland Pits NR, Friday Wood & Cherry Tree Lane, and The Naze which I hope to get to later this week depending on the weather.

As for the top three species in March, these are the sites that they were found:
Brimstone were in greater numbers than the other two over-wintering species early on, with Peacock taking over towards the end of the month. Comma have been relatively stable and in healthy numbers throughout March. As far as the day is concerned, Peacock could be seen from early morning, followed by Brimstone towards the end of the morning, and Comma active during the morning but basking territorially, perched most commonly on a bramble leaf, well into late afternoon when the most sightings were recorded. Brimstone numbers have dropped significantly since the sighting of 50 at Hatfield forest, mentioned above. Notable is the fact that 93 of the 112 recorded sightings of Brimstone have been at Hatfield Forest with very few recorded elsewhere. Out of 112 Brimstone sightings, I have only seen one female and she was attached to a male. Hopefully, my first visit to Great Holland Pits where I know where the Alder Buckthorn Frangula alnus is will change that. It also shows that if you want to see large numbers of Brimstone in Essex you need to go to Hatfield Forest during March.

it won't come as any surprise that each of the three most seen species were seen in highest numbers at the sites where the highest abundance of butterflies occurred. However, only 4 of the 8 species seen during March were seen at Hatfield Forest. With the emergence of Speckled Wood and Green-veined White this will change with the ride profile showing that these species will increase their percentage composition throughout April with the numbers of over-wintering species dropping off. The site with the most butterfly diversity so far is Benfleet Downs, Hadleigh Country Park, & Belton Hills with 7 of the 8 species seen, lacking Speckled Wood so far - and you can add an eighth with Small White yesterday, the whites starting to appear in good numbers due to the mass of Charlock Rhamphospermum arvense present and a field of brassica in the Hadleigh Farm area on the walk to Belton Hills. That should make things interesting soon as I have already seen a pair of Small White in cop, and two females ovipositing at the top of the hill in Benfleet Downs.

Highlights

50 Brimstone at Hatfield Forest including a pair in cop The number of Peacock & Comma The beautiful Small Tortoiseshell [hanging on] The first of the emerging Whites And a sighting of a Speckled Wood on the 31st of March

David Lazarus wrote: ↑Wed Apr 02, 2025 7:55 am...In terms of numbers, 545 recorded sightings of 8 species during March is quite good...

I'd say that for March those numbers are spectacularly good, David.

I saw around 100 and thought that was highly satisfactory.

The Butterflies of Essex
Site Locations

Hatfield Forest
Site visit 11.04.2025

Brimstone 63
Large White 9
Green-veined White 20
Orange-tip 35
Peacock 65
Comma 9
Speckled Wood 4

Total 205

This is the first time during 2025 that recorded sightings topped 200, with ideal site conditions of 20C [feels like 22C], little breeze, and full sun.

Current Ride Profile

Brimstone 31%
Large White 4%
Green-veined White 10%
Orange-tip 17%
Peacock 32%
Comma 4%
Speckled Wood 2%

Comparison to the previous visit made on the 04.04.2025: 152 recorded sightings

Brimstone 24%
Large White 3%
Green-veined White 4%
Orange-tip 1.5%
Peacock 57%
Comma 10%
Red Admiral 0.5%

Most notable aspect of the change on ride profile is the emergence of whites to increase their share of the composition at the expense of Peacock and Comma, with Comma numbers reducing significantly.

Some interesting [preliminary] observations from the 5 site visits during the spring of 2025:
06.03.2025; 20.03.2025; 27.03.2025; 04.04.2025; & 11.04.2025

1. As would be expected, Peacock were up earliest [9.30], but perhaps more unexpectedly so were the Orange-tip, before Brimstone [10.30/11], and then the other two whites joined them. Brimstone and Orange-tip also flew to after 4 o’clock. Brimstone recorded sightings tend to be higher during 11.00 and 13.00, with Brimstone in flight into late afternoon at Hatfield Forest in smaller numbers. Yesterday, both male and female numbers were high during the afternoon, most notably females.
2. No Small White identified, but there were some possibles that were not recorded. There have been no confirmed recorded sightings of Small White during any of the visits during 2025, but they were recorded in 2024.
3. First Comma sighting of the day was at 3 o’clock, which was a great surprise, but most Comma sightings are recorded in late afternoon during all visits including the day when temperatures were low and the sun was not strong until late in the day
4. First Speckled Wood followed shortly after at around 3.10 - they were only seen along the ride through Street Coppice to Gate 38
5. Brimstone numbers were boosted from the previous high of 50 during the first week of March by the females actively searching and ovipositing on Alder Buckthorn Frangula alnus.
6. Peacock numbers have always been high except for the first week of March [3], when Brimstone and then Comma [during the cold spell] sightings were the highest recorded.
7. Orange-tip and Green-veined numbers are rising - first significant numerical total for Orange-tip during 2025 with 34 of the 35 being male
8. No Small Tortoiseshell at Hatfield Forest during 2025; none recorded during 2024
9. No Holly Blue sightings yet

Some images, with flight photographs for both sexes of Brimstone, a male Orange-tip, and a female Peacock oviposisting:

The Butterflies of Essex 2024 Year in Review
Holly Blue continued

South Essex

The following sites are where sightings of Holly Blue were recorded by me during 2024 within South Essex:
Baddow Meads, Meadgate Fields Open Space, & Great Baddow More than most of the other butterflies of Essex, I would see Holly Blue within residential areas, gardens, and along paths. There is one path running from Meadgate Fields Open Space to Baddow Road that runs through abundant Holly Ilex aquifolium and Ivy Hedera helix, which in places forms an arch. During 2023, this is where I saw a greater density of Holly Blue than anywhere else I visited. Unfortunately, this was not the case in 2024. As already mentioned, numbers of Holly Blue along my transect are highly inflated because of the weekly walk resulting in individuals being over-counted. Despite that, the abundant Holly & Ivy locally provides large areas of suitable habitat and consequently numbers are relatively high locally.

Baddow Meads - Holly Blue were seen on 8 occasions with the first sighting on the 17th of May. No more than 3 were seen at any one location on a single visit [twice - on the 17th & 27th of May], with a single sighting being usual. All sightings were first brood apart from one seen from the second brood on the 01st of September. Total: 16
Also, Chaucer Road Meadow [River Chelmer floodplain] Total: 2
Meadgate Fields Open Space - Holly Blue were seen on 14 occasions with the first sighting on the 29th of April. The highest daily total was 5 on the 02nd of June. Once again, all sightings were from the first brood apart from one seen from the second brood on the 07th of August. Total: 33
Garden on Meadgate Avenue - Holly Blue were seen on 27 occasions with the first sighting on the 15th of May. The same individuals were recorded multiple times, with the highest daily total of distinct individuals being 5 on the 18th of May, with 4 seen a month later on the 04th of June - estimated number of first brood individuals around 10 only. single sightings of second brood individuals took place between the 30th of July and the 10th of August with an estimate of 2 maximum for the garden colony. Total: 50
Meadgate Park - Holly Blue were seen on 23 occasions with the first sighting on the 18th of April. Once again numbers are exaggerated because of multiple visits during which the same individuals were recorded on more than one occasion. However, there is a south-facing Ivy wall which is ideal habitat for various species of butterfly, in particular the Holly Blue so there is no surprise that the highest recorded sightings were at this site. The highest daily total was 10 on the 18th of May at the peak of the first brood emergence locally. No more than a daily total of 2 were seen of the second brood which took place between the 03rd and 9th of August after which they disappeared. Surprisingly two fresh individuals were seen on the 16th of October. Total: 68
Other sites within Great Baddow including the aforementioned alley, Baddow Hall Park, residential walkways. One of the first sightings of the year was seen in the alley on the 14th of April. Total: 14
Overall total for the local area including Baddow Meads, Meadgate, & Great Baddow: 150
Lingwood & Danbury Commons, and the Danbury Ridge Nature Reserves The first Holly Blue of 2024 was seen at Lingwood Common on the 13th of April. The two commons and all of the Danbury Ridge Nature Reserves have wooded areas with abundance sub-canopy layers of Holly Ilex aquifoilium and Ivy Hedera helix. Despite this very few Holly Blue were seen across the whole of this expansive area. Most worryingly, like many species that you would expect there, not one Holly Blue sighting was recorded at Danbury Common.

Lingwood Common - Holly Blue were seen on three occasions with the first sighting on the 13th of April, with two second brood seen singly on the 14th of July with the last one on the 19th of August. Total: 3
Danbury Ridge Nature Reserves - Holly Blue were seen on only one occasion, the 20th of May, when singles were seen at Little Baddow Heath and Scrubs Wood. Total: 2
Danbury Village - within the residential area of the village. Total: 2

EWT Maldon Wick Nature Reserve Once again, it is more noticeable how few Holly Blue were seen at sites that have large areas of suitable habitat and larval food sources. I did not visit as often as I would have liked and Holly Blue was not my target species as it was not at Danbury, but even so, numbers were disappointing.

EWT Maldon Wick NR - Holly Blue were seen on two occasions only, the 10th of May and the 23rd of June. Total: 6
Also, residential areas of Maldon village. Total: 5

Thrift Wood Best known for being one of the sites where Heath Fritillary were introduced, it proved to be short-lived and the wood is mostly very poor for butterflies although it has a clearing within the centre, and the woodland edge has suitable habitat for a number of species. Once again, despite ample Holly & Ivy numbers were lower than expected.

Thrift Wood - Holly blue were seen on a single site visit on the 02nd of June. Total: 7

Fen Creek, Marsh Farm Country Farm, & South Woodham Ferrers
The River Crouch estuary is not a habitat that is suitable for Holly Blue with only a few from the third brood seen around the residential areas close by during the trek around the Essex Saltmarsh Coast.

Fen Creek & South Woodham Ferrers residential area - Holly Blue was seen on a single occasion on the 13th of September. Total: 3
Hockley Woods Hockley Woods was one of the few places where numbers were good, distributed evenly throughout the main rides and along the south-facing woodland edge. The wood has wide rides. clearings, and glades with ample Holly and Ivy which supports healthy colonies of Holly Blue. Sightings were relatively good despite this species not being a target species in the home of the Heath Fritillary.

Hockley Woods - Holly Blue were seen on 5 occasions with the first sighting on the 24th of May. The highest daily total was 12 on the 09th of June. The last sighting was on the 04th of July, with no visits during the second brood. Total: 25
Pound Wood & Hadleigh Great Wood
As with Hockley Woods, Pound Wood and Hadleigh Great Wood are the South Essex Woods where Heath Fritillary were reintroduced. I visit to monitor Heath Fritillary numbers and searching for Holly Blue is not my focus. Despite suitable habitat, numbers in both woods were low.

Pound Wood - Holly Blue were first seen on the 08th of June with a further sighting of a first brood on the 17th of June which was the day when the daily total across both woods was at its highest [5]. Singles were only seen at Pound Wood with the final one, a second brood on the 15th of August. Total: 3

Hadleigh Great Wood - Holly Blue were only seen on a single occasion on the 17th of June. Total: 4

Two Tree Island The Essex Wildlife Trust nature reserve of Two Tree Island within the Hadleigh Ray which flows into the Thames Estuary, is reclaimed land south of Leigh-on-Sea which is now used for recreational purposes and nature. It is part of the Essex Saltmarsh Coast and the reserve favours the conservation of birds. The west side is mostly open grassland with scrub, whereas the east side is mostly scrub with trails throughout and favours a wide range of butterflies, including Holly Blue. I do not visit often.

Two Tree Island - Holly Blue were only seen on a single occasion on the 28th of August. Total: 3

Benfleet Downs I only visited Benfleet Downs during the later months of the season whilst searching for Wall during which time I came across a few second brood Holly Blue. With more often visits during 2025 throughout the whole summer, I would expect to see many more as the woodland areas through which the trails and bridleways pass, are ideal habitat for Holly Blue.

Benfleet Downs - Holly Blue were seen on two occasions, the 28th of August and the 17th of September. Total: 2

Langdon Hills Country Park
As Holly Blue numbers are expected to be low during the spring of 2025, I will be keeping my eye out for this species at various locations within the Langdon Living Landscape. In particular, the wooded areas of Northlands Wood, Willow Park, Marks Hill Nature Reserve, as well as One Tree Hill have ideal habitats for all woodland specialists and I hope Holly Blue show some signs of recovery at these places.

One Tree Hill [Hawksbury Bush, Johnson's Meadows, & Martinhole Woods] - Holly Blue were seen on 8 occasions with the first sighting on the 11th of May. The highest daily total of 7 were seen on the 25th of June. Most sightings were first brood, with the final sighting, and only one of the second brood taking place on the 17th of September. Total: 21
Willow Park - Holly Blue wee only seen on two occasions with singles of each of the two broods, on the 19th of May and the 13th of September. Total: 2
Northlands Wood - Holly Blue were seen on 3 occasions, with 3 first brood on the 25th of June, and singles of the second brood on two occasions, the 13th of August & 17th of September. Total: 5
Also, 2 were seen within the residential area of Basildon. Total: 2
RSPB Rainham Marshes
Rainham Marshes is a site that, on the face of it, does not seem to be that suitable for butterflies but surprisingly hosts a number of species that would not be expected, This includes the relatively high numbers of Holly Blue within small areas of woodland and scrub.

RSPB Rainham Marshes - Holly Blue were seen on only two occasions when searching for other target species. First brood were seen on the 17th of July, and second on the 17th of August with this date being the time of the highest daily total of 14. Total: 16

The Butterflies of Essex 2024 Year in Review continued

North Essex

The following sites are where sightings of Holly Blue were recorded by me during 2024 within North Essex:
Hatfield Forest

Surprisingly, there was only one recorded sighting of a Holly Blue throughout all of the site on the 26th of June. Total: 1

River Can, River Chelmer [north], and North Chelmsford
Along with the areas of the floodplain south of the River Chelmer to the east of Chelmsford, the area north, and north-west Chelmsford, provided the most recorded sightings. This included my mother's garden which is a garden full of Holly & Ivy and supports a healthy colony.

Garden on Chignal Road - Holly Blue were seen on 11 occasions with sightings of both first and second brood. The first sighting was on the 30th of April with the highest daily total of 7 on the 29th of May. 27 first brood were recorded up to the 18th of June. Only 3 second brood sightings were recorded from the 06th of August with the final sighting taking place on the 16th of September. Total: 30
Admirals Park Local Nature Reserve - Holly Blue were seen on 5 occasions with the first sighting on the 07th of May. The highest daily total was 4 on the 08th of May. The final sighting was on the 18th of June. Total: 9
Chelmer Valley Local Nature Reserve, Newland Grove Local Nature Reserve, & Little Waltham Meadows Nature Reserve - Holly Blue were recorded on a couple of occasions on the 09th & 12th of May. Total: 10
Also, a further 10 were seen throughout the residential areas of Chelmsford.

Overall Total for Chelmsford & mid-Essex [including areas within both vice-counties of North & South Essex]: 269 out of a total of 388 recorded sightings within Essex EWT Great Holland Pits
The north-east of Essex seemed to have more Holly Blue sightings of both broods than in the south and mid-Essex during 2024. Great Holland Pits is a site that has suitable habitat for supporting a higher population than I saw, but I was not targeting Holly Blue while I was there.

EWT Great Holland Pits - Holly Blue were seen on 3 occasions with the first sighting on the 02nd of May. The highest daily total of 6 occurred on the 22nd of June. The final sightings of second brood Holly Blue took place on the 26th of August. Total: 9
Holland Haven Marshes & Country Park
Holland Haven is not a site that I visit very often, and only on the way for Great Holland Pits to The Naze. On the single occasion I was there, I recorded surprisingly good numbers for the 2nd brood. Further south along the coast towards Clacton-on-Sea is a footpath that runs passed Eastcliff Sports Ground in Holland-on-Sea where very large numbers of Holly Blue were seen regularly.

Holland Haven Marshes & Country Park - Holly Blue was seen on a single occasion on the 26th of August. Total: 9

Walton-on-the-Naze & The Naze
Given that large numbers were seen in this region, I saw very few Holly Blue in comparison and that included not seeing any Holly Blue at the Naze. The few sightings I did see were in the residential area and along the esplanade at Frinton-on-Sea.

Walton-on-the-Naze - Holly Blue were seen on two occasions with a few 2nd brood only seen on the 26th of August & the 15th of September. Total: 3
Frinton-on-Sea esplanade - Holly Blue was seen on a single occasion on the 26th of August. Total: 1

Stour Wood & Copperas Wood
Two sites that support woodland specialists, I would have thought that both woods would provide suitable habitat for larger numbers than I saw on my single visit.

Copperas Wood - Holly Blue was seen on a single occasion on the 24th of June. Total: 1

Also, singles were seen at Great Notley Country Park on the 08th of August, and in the residential area of Tiptree on a visit to Tiptree Heath, where none were recorded, on the 23rd of June.

The Butterflies of Essex
Site Locations

Baddow Meads
Site visit 24.04.2025
After the excitement of Grizzled Skipper, Brown Argus, & Small Heath within the meadows at Langdon Hills Country Park, it was back to some sort of normality with the usual suspects. I spent an afternoon walking a circuit around my local patch within the floodplain of the River Chelmer. It was just cooler than the warmth needed for most species to take flight with a chill gentle breeze making it feel cooler than the actual air temperature. It meant that there were less butterflies in flight, and the recorded sightings per species reflect this. It was cool enough for Peacock to enjoy their time during the sunny intervals and they regularly popped up on the path adjacent to the nettle patches as I was walking passed. When I set off at 11.30, it was the Speckled Wood that were in good numbers within the woodland clearing at Meadgate Fields Open Space. After this I saw few butterflies for the first couple of hours or so as only those which have adapted to the cooler and changeable weather with lower light levels than during the warmer months, such as the Peacock, were in flight.

This meant that it turned out into a female day. With very few males in flight to bother them, females took the opportunity to look for the most suitable plant to lay their ova on. As such, it turned out to be quite an interesting afternoon with few males seen until the temperature was high enough for them to appear, and this was not until late afternoon.

First was a beautiful little Orange-tip fluttering between the Garlic Mustard Alliaria petiolata on the banks of a stream flowing through the farmer's fields of the eastern parts of the floodplain. The habitat is very suitable for several species as I mentioned during a previous post. Not only are there large patches of Garlic Mustard for Orange-tip and Green-veined White, the large patches of Nettles Urtica dioica along this stream favour Small Tortoiseshell and Peacock also. I have not seen Comma in this part of the floodplain but I would have thought they would benefit from this habitat too. Close by are the ponds of The Mill Carp Fishery with Willow species around their banks and shrubs around the boundaries - these include Hawthorn Crataegus monogyna on which I am hoping to find Green Hairstreak, and Alder Buckthorn Frangula alnus favoured by Brimstone.
This location was where I found the female Orange-tip ovipositing.
And the ova was placed on a small leaf at the top of a flowering stem adjacent to an opening flower bud:
Close-by I found a female Speckled Wood ovipositing on the tall grass left along the boundary fence of the pond but I did not want to disturb her while she was actually laying. She was also a stunner, a lot darker with brighter yellow/gold markings than the ones I normally see locally within Meadgate Fields Open Space which is about a couple of miles away. Unfortunately, my iPhone does not really capture the contrasting colours that can be seen by eye:
The others were seen on the northern banks of the River Chelmer closer to the city where there are no agricultural fields nor the damage done to the plants around the field verges by herbicides sprayed by farmers to prevent the encroachment of nettles and brambles, and other 'weeds'.

First up was a female Large White ovipositing on some of the agricultural escapees, Brassica spp. such as various mustards & rape from the surrounding farmers fields, used as cattle feed.
Once again I did not want to disturb her unnecessarily as she would take some time before she had finished laying her 20 or so ova on the underside of this Brassica leaf. Just down from her was a Small White doing the same. This time, I could not get close enough to her to catch her in the act.
And a little further down was the third of the whites, a female Green-veined White that was fluttering around low in the undergrowth attempting to find the position of her ideal plant. I managed to get a flight-shot only, and left her to it:
By this time it was nearly 4 o'clock and the afternoon became warm with full sun and a lower breeze, almost still in places. The habitat had changed from earlier with large areas of Nettle and Poison Hemlock Conium maculatum [a exceedingly beautiful plant with large fern-like foliage and more delicate-looking flowers than the earlier-flowering Cow Parsley Anthriscus sylvestris found along woodland edges]. Small Tortoiseshell, Peacock, & Comma love to perch on the top of these leaves and can be seen basking in the late afternoon sun as they were yesterday - unusually side-by-side:
I came across two or three female Peacock ovipositing but none in the act. Some were still looking resplendent:
Having completed a five hour walk with butterflies along a 12 mile round trip, by late afternoon it was time for the sunbathers, and surprisingly some busy bees:
Not a bad count in the end, nearly 100 recorded sightings with 37 Peacock, 31 whites, numerous females of 6 species ovipositing, 5 more Red Admiral arrivals to the nettle-paradise, and another 3 recorded sightings of Small Tortoiseshell to make 37 within the floodplain of the River Chelmer.

I can now take a break before probably the busiest week of the season so far during the upcoming week if the forecast is to be believed - that will start things rolling with the Spring Festival along the Thames Estuary Path near East Tilbury being one of the highlights, I expect.

Once again, some happy days to come, hopefully, with at least one new species of 2025 expected, one of my favourites, those little blighters, the Wall, and you never know - Painted Lady & Clouded Yellow.

Peacocks still showing impressively I see, David.

Make the most of your break as things look set to warm up again very soon.

The Butterflies of Essex
Site Locations

Thames Estuary Path
Site visit 30.04.2025
It is time to walk down the Thames Estuary Path south of Mucking Marshes Landfill to observe the first brood Wall at their peak. There are now males and females on both sides of the seawall, and all in pristine condition.
In addition there are very good numbers of both male and female Orange-tip - again on both sides of the seawall. If anything, there were more females on the river side of the wall.
With Green-veined White still in good numbers as well.
I was also pleased to see so many Small White.
Peacock numbers are finally reducing and they are starting to look tatty.
A bonus was a couple of Small Tortoiseshell at Stanford Warren Nature Reserve - not in great condition but still pleasing to see.
I took a look at the late afternoon activity at One Tree Hill on my way home where I found Common Blue had started emerging, Small Heath numbers were growing, and another Brown Argus sighting - a male.
A very good day with over 200 recorded sightings again - and a morning ticket to the Spring Festival was a lot more chill, my kind of day. With the start of next week not looking good, the next couple of days are looking like a good time to see Wall at their best.

The Map Grid Reference you want to be heading for is TQ69397870 - a 200 metre south-west facing length of seawall - a very special place and a habitat butterflies obviously love.