David Lazarus

[David Lazarus]

A species focus on the Heath Fritillary in Essex: status - highly threatened
28/06/2024 Site visit: South Essex woods

In The Heath Fritillary in Essex - 2015 report, produced by the Essex Wildlife Trust Biological Resource Centre, the collected data for adult trends showed that the populations in the four Essex woods in which the Heath Fritillary was introduced were still in decline and that the butterfly was severely threatened with extinction.

The report contains the following conclusions for each of the woods:

1. Hockley Woods
Population Trend: stable, following severe decline
Population Status: at risk

2a. Hadleigh Great Wood
Population Trend: severe decline
Population Status: severely threatened

2b. Dodds Grove
Population Trend: stable at low levels
Population Status: severely threatened

3. Pound Wood EWT
Population Trend: severe decline
Population Status: severely threatened

4. Thrift Wood EWT (SSSI)
Population Trend: severe decline
Population Status: extinct (2014 to present)
There are no plans for EWT to reintroduce the Heath Fritillary at this site despite the wood sustaining a population for 30 years up to 2013.

This leaves the three sites Hockley Woods, Hadleigh Great Wood & Dodds Grove, and Pound Wood with the Heath Fritillary continuing to be a highly threatened species vulnerable to extinction at all three woods in Essex. These are the three sites that I have collected data and observed the health of the Heath Fritillary and the patches of Common Cow-wheat Melampyrum pratense, an annual plant, on which it depends.

Nearly ten years later, the Essex Wildlife Trust this week released a news article entitled Highest number of heath fritillaries recorded where they state that the record numbers of 148 heath fritillary butterflies were announced in 2019, and that record was beaten in 2024 during which 218 were recorded at Pound Wood nature reserve in south Essex, making it the highest number the Trust has seen to date. [source: https://www.essexwt.org.uk/news/highest ... s-recorded].

I have visited 4 times during the last month with my penultimate visit taking place on Friday 28th June last week. Although the weather conditions were not ideal for this warmth and sun-loving butterfly, it was sufficiently good enough during the brief sunny intervals to collect data on adult numbers. My final visit next week will be subject to the weather with the forecast not great.

Hadleigh Great Wood has one tatty female left signalling the end of the flight period for 2024 at this site for another year especially given the cool, wet weather forecast for the next four days. I personally have not seen more than 4 at this site in only one colony of the two places left with sufficient cow-wheat to sustain a population. Others have found 12 or so. No one has found Heath Fritillary at Dodd's Grove and the glade is not currently in a state to attract further colonization.

Heath Fritillary female
Hadleigh Great Wood 28/06/2024

The news is far better at Pound Wood and Hockley Woods where the main colonies now reside. I counted 55 Heath Fritillary at Pound Wood on Friday down from a peak of approximately 100. At Hockley Woods I counted 59 which is down from a peak of between 200-250 individuals. Over the 3 woods, I would say the peak count for 2024 was around 350. I would question the count of 500 at Hockley Wood on one day as a significant exaggeration. I actually think the EWT's count of 218 was probably an over-estimation being double the amount I saw on two occasions during the peak flight period.

It will probably be no surprise to you that at both sites there were fewer males seen than on previous visits. There were some freshish-looking females at Pound Wood:

Heath Fritillary female
Pound Wood 28/06/2024

and this included some being pestered by males and some laying eggs:

Heath Fritillary female
Pound Wood 28/06/2024

But you are more likely to see this now at Pound Wood:

Heath Fritillary female
Pound Wood 28/06/2024

than a few of these:

Heath Fritillary male
Pound Wood 28/06/2024

But there is always the occasional beauty to behold:

Heath Fritillary female
Pound Wood 28/06/2024

It is much the same at Hockley Woods in the main four colonies within the South Essex Woods, with significant reductions in abundance and what is there containing a higher percentage of females that have been around for a week or so:

Heath Fritillary female
Hockley Woods 28/06/2024

with a few newly emerged ones:

Heath Fritillary female
Hockley Woods 28/06/2024

the odd dead one:

Heath Fritillary male
Hockley Woods 28/06/2024

but the majority are not looking at their best:

Heath Fritillary
Hockley Woods 28/06/2024

having said that, there is still a bit of activity going on:

Heath Fritillary
Hockley Woods 28/06/2024

It has been a joy and delight to be amongst this beautiful, delicate, and vulnerable species for the past month. The Heath Fritillary is one of my favourite butterflies and I cannot wait to do the whole thing again in 2025 and beyond.

One sadness was the amount of flattened vegetation. Unfortunately, I suspect most of this was the result of butterfly enthusiasts attempting to acquire the perfect shot while ignoring the fact that there was plenty of larva and pupa under their feet. Some of the areas in both Hockley Woods and Pound Wood had grass patches that had been trampled on resulting in significant loss of perching, basking, & roosting sites as well as places that the Heath Fritillary enjoy meeting the opposite sex. The Heath Fritillary also lays it's eggs low within the grass and plant litter close to the cow-wheat. Please, if you are going to the woods, keep to the paths or the visible trails through the cow-wheat, and don't venture off them into the vegetation even if it is grass or over plant litter - certainly please do not trample on the cow-wheat. And please watch your feet as they are low flying and regularly rest on the floor within vegetation and leaf litter.

Enjoy, and celebrate the fact that 2024 had a healthy emergence of Heath Fritillary in Essex.

[Padfield]

I'm right behind you on that one, David. The trampling of foodplants, nectar plants and anything else that might come between a photographer and that perfect photo is the main reason I never publicise my sites. They say, 'Take only photos, leave only footprints', but I believe you should try very hard not even to leave footprints (and certainly not body rolls).

Bizarrely, I think I might never have seen a heath fritillary, Melitaea athalia. I've never seen one in the UK, and all the heath fritillaries I've seen in Europe are within the range of the recently split Melitaea nevadensis. Maybe back in the Brenne when I was a schoolboy ... Anyway, I ought to make it a mission for next year! You have some great photos of the Essex heath frits.

Guy

[David Lazarus]

I ought to make it a mission for next year! You have some great photos of the Essex heath frits.

It would be my pleasure to show you the hot spots when you are next in Essex, Guy - message me when you are back in the UK. At the moment, I am with you about advertising the sites. However, in this case everyone knows where they are [to a certain extent] and when they are flying. The exact hot spot locations are not universally known. I want signage to be put up for next year saying please keep off the conservation area which others may say shows the hotspot locations. But I think there needs to be some balance by letting butterfly enthusiasts know about the health of this wonderful butterfly whilst emphasizing their role in being responsible for the conservation of this vulnerable and highly at risk insect, not only in Essex but the UK.

Thanks ... the photos are just a snap shot of week 4 post-peak. I have some absolute stunners from weeks 2 and 3. I was determining the percentage of sexes in the colonies. As you probably know they are easy to photograph when they are waiting for the sun to come out - I took photographs of each of the first 75 individuals [out of 81 in the colony at Pound Wood] that were easily reached along the paths and trails. I am hoping to complete a report of the season at some point - I will include some.

[David M]

Many thanks for that report, David. This is an exceptionally common butterfly in continental Europe so it's easy to forget how precious it is in our own country.

I hope these declines can be reversed.

[millerd]

Some excellent background info on the Heath Fritillary populations in Essex, David. I have regularly visited Both Hockley and Pound Woods over the last 15 years and have noted considerable fluctuation in numbers. I've also seen them at Little Haven (close to Pound Wood and along the same power transmission line: they were flying in the wayleave under the wires), but I think that colony died out. However, it's great to hear that numbers are up this year (something mirrored in the large colonies over in Kent in Blean Woods, I believe) and the declines noted in 2015 have been halted. Certainly on my visit to Pound Wood on 23rd June, there were plenty around.

Cheers,

Dave

[David Lazarus]

11/11/2024 Site visit: Friday Wood & Cherry Tree Lane

Friday Wood, Cherry Tree Lane

Friday Wood, part of the Roman River Site of Special Scientific Interest, is an ancient woodland, modified in places by plantations of conifers and sweet chestnut. It is part of the government's Defense Estates and hosts a military corrective training facility. There are also three working farms and private property restricting access in some places. Overhead electric pylons run straight through the centre of the area of interest.

It is composed of an intricate mosaic of habitats including secondary woodland and scrub interspersed with open grassland and heathland, with wetland habitats in the valley bottom to the south. Further south is Abberton Reservoir into which the Roman River drains, and where there is an Essex Wildlife Trust Nature Discovery Park.

The habitats within the Friday Wood and Cherry Tree Lane area are famous for the almost one thousand types of butterflies and moths that have been recorded there, including numerous rare species. It is one of the best sites for butterflying in Essex for both woodlanders and open ground habitat species.

It was my first visit in my quest to discover and map the main hot spots for sighting Purple Emperor, White Admiral, and Silver-washed Fritillary, as well as the Hairstreaks, and anything else that might appear during my visits.

I could have chosen a day with better weather conditions for my visit, but I was desperate to get out and about after days of what is becoming a disappointingly dull, wet, overcast July 2024. It remained grey overhead with sporadic sunny intervals. The light winds made it feel cooler than the 17C temperatures. Because of this the butterflies were inactive for most of the day, which made it easier to approach and photograph grassland species but frustrating to accomplish my main objective of tracking down the haunts of the premium woodland species.

I arrived at around nine o'clock in the morning at the north east access point and put in a nine hour shift analyzing and evaluating the habitats, GPS mapping the most likely places to view butterflies, as well as looking out for and photographing the odd butterfly here and there. A very interesting day, despite the weather. Most importantly, perhaps, I continued to learn about butterflies and their habitats.

Not surprisingly, given the dull cool morning with dew still on the vegetation, the Ringlet was the first butterfly to take to the wing. The first of 68 Ringlet, continuing what appears to be a good year for them in 2024 here in Essex - at least, it feels like a better year than 2023:

Ringlet
Friday Wood 11/11/2024

As it was so grey and a little cool I kept to the open areas where a few butterflies could be seen. The first thing that caught my eye was how light the Meadow Brown were - much lighter than the very dark ones I see around my local patch to the south. I think these are some of the lightest I have ever seen anywhere:

Meadow Brown male
Friday Wood 11/11/2024

And this female is particularly striking, I think:

Meadow Brown female
Friday Wood 11/11/2024

I recorded 148 Meadow Brown in total across the site, this being the highest species count for Friday Wood. However, this is definitely a 500+ site given optimum weather conditions and the vast areas of open grassland.

The Gatekeeper numbers are continuing to rise in Essex as more of these beautiful butterflies emerge - 39 in total but once again this is a 300+ site with the amount of woodland edge, scrub, and adjacent tall grass to be found. I saw some stunning individuals with this very vibrant, dark male, that had immaculate white fringes, taking top spot:

Gatekeeper male
Friday Wood 11/11/2024

The morning could not be complete without a skipper density count whilst they were predominantly sedentary. No surprises, being Essex, that of the first 25 that I identified I did not find a single Small Skipper. This would be the case until the last moment before I headed home. In total I had 30 confirmed sightings of Essex Skipper including a male version of the ones with dark bleeding into the veins:

Essex Skipper male
Friday Wood 11/11/2024

At around midday a sunny interval descended and I quickly ran to an area I had identified earlier as a possible hot spot for Purple Emperor with a mix of Grey Willow Salix cinerea & Goat Willow Salix caprea scrub with Pedunculate & Sessile Oak standards Quercus robur & Quercus petrea respectively:

Friday Wood possible Purple Emperor hot spot

At this point in the wood there is a small open area at a dip in a ride which acted as a sun trap - south-facing:

Friday Wood 11/11/2024
Sallow scrub with oak standards, and flowering brambles

And it is here that I witnessed a dog fight between two male Purple Emperors. There were also three male Silver-washed Fritillary gliding around and investigating any insect that moved whilst settling on the brambles and taller herbaceous plants - but too far away from me to photograph. A little further up the hill to the east there were another couple of SWF as well as a passing White Admiral. As quickly as the full sun appeared, it was gone and pretty much for the rest of the afternoon also. And disappointingly that meant the end to any chance of recording any further sightings of the woodlanders.

To be continued.

[David Lazarus]

21/07/2024

My garden management is paying off at my mother's garden here in Chelmsford with a healthy colony of 8 newly emerged Gatekeeper so far following on from the little colony of Meadow Brown that are down to around 3 or 4 now. I witnessed some males taking a keen look at a beautiful looking female. This may be post cop as she was still in the same place within some ivy or perhaps just trying to avoid other males pestering her. She has some very interesting spotting:

Gatekeeper female
Garden on Chignal Road, Chelmsford 21/07/2024

And one of the males was looking rather handsome with a couple of extra spots too:

Gatekeeper male
Garden on Chignal Road 21/07/2024

The garden also had all 4 whites for most of the day, with 3 Green-veined White including a female, a female Small White - which seems a rarity these days - outnumbered by 5 or 6 Large White including a female ovipositing, and a couple of Brimstone, male & female.

Small White female
Garden on Chignal Road, Chelmsford 21/07/2024

Having said it was a rare occurrence around here at the moment, I did find a beautiful one the day before in Baddow Meads:

Small White female
Baddow Meads 20/07/2024

Star of the show though was this lovely lady and her 28 ova laid under a Variegated Nasturtium leaf:

Large White female ovipositing
Garden on Chignal Road, Chelmsford 21/07/2024

Large White ova
Garden on Chignal Road, Chelmsford 21/07/2024

Spring saw large numbers of Peacock and they are starting to emerge here in Chelmsford with a couple in my mother's garden as well as a few stunning Red Admiral:

Red Admiral
Garden on Chignal Road, Chelmsford 21/07/2024

And Comma have started well this summer with one in the garden as well as a few on the walk home:

Comma
Garden on Chignal Road, Chelmsford 21/07/2024

As nice as it was to see so many today, yesterday evening I saw an absolute stunner of the red tint kinda style that I love. He was also frequenting one of my favourite butterfly of the year's perch from the Spring - so it was really great to see his territorial replacement;

Comma male
Meadgate Fields Openb Space 20/07/2024

On the way home there were more stunning Peacock:

Peacock
Admirals Park LNR 21/07/2024

as well as the obligatory Essex Skipper, being Essex, in classic ES identification feature dipped in black ink pose:

Essex Skipper
Admirals Park LNR 21/07/2024

On my return home, I was delighted to find that the colony of Gatekeeper had expanded overnight from 3 to 6 - which is still a long way short of 2023's count of 19. After only a couple of days, the poor female is not looking as fresh as the one this morning but hopefully she is waiting for her ova to fertilize after all the activity:

Gatekeeper female
Garden on Meadgate Avenue, Chelmsford 21/07/2024

With the start of the week bringing more sites to visit, it was good just to be with the butterflies today - even if I could not keep bringing the iPhone out for a few photo opportunities [as you do].

[Wurzel]

Lovely looking Gatekeeper David The extra spots on the fore wing would make it a slight excessa and the extra eyes on the hind wing would be post-excessaI think How are you managing the garden - is it mainly planting or are you using a pruning regime?

Have a goodun

Wurzel

[David M]

Great view of the Essex Skipper, David. No doubt about that one!

[David Lazarus]

Great view of the Essex Skipper, David. No doubt about that one!

[David Lazarus]

Lovely looking Gatekeeper David The extra spots on the fore wing would make it a slight excessa and the extra eyes on the hind wing would be post-excessaI think How are you managing the garden - is it mainly planting or are you using a pruning regime?

I take the hands off approach Wurzel after designing habitats based on the semi-natural habitats we see when we are butterflying - obviously with the right plants for each of the species needs including larval food source, perches, basking sites, roosting etc., not just loads of flowers But I need to compromise for us humans too - who generally do not understand what I am doing. So for instance, I make sure the 'messy' wildlife friendly parts are 'framed' so the eye of humans can see some design and/or it looks cared for. But then there is what works, what does not - and many edits, adjustments, trial and errors..... and if that is not enough, I have to pretend I am a grazing animal in the open ground areas, and coppice, prune to let the light in etc., in the wooded areas.... but the prime asset for all our beautiful insects is a hedge!!!

but not straightforward, always monitoring and always learning from my mistakes which have been many over the years.

I also have two hedgehogs in their homes and provide them with what they need too - but my pride of place are the Gatekeeper whose colony peaked at 19 last year but sadly is only a third of the size. Perhaps because what I have done or not done to benefit them or the weather has hit them as much as they have hit the Meadow Brown.

It does not sound very 'hands-off' does it

Thanks for asking, and also info re: Gatekeeper aberration much appreciated, and also have a goodun Wurzel

[Wurzel]

"It does not sound very 'hands-off' does it " sounds awesome I particularly like the idea of 'framing'. One mans mess is anothers' complex beauty

Have a goodun

Wurzel

[David Lazarus]

On a hot, dry day with 26C temperatures and light winds I walked my transect regretting that I was out in the afternoon sun when it seems even the butterflies were struggling with the heat. Although it was quiet, with only 136 recorded, I was pleased to see the blues were in flight - late, but sufficient numbers to provide me with some hope that they will get through this difficult year.

The male Speckled Wood were in reasonable numbers but not comparable to the Spring brood:

Speckled Wood male
Meadgate Park 01/08/2024

There were only 12 butterflies active in the meadow at Meadgate Fields Open Space with just 6 browns which was disappointing. However, a male Common Blue was flitting around searching for females and pausing to nectar on Bird's-foot Trefoil Lotus corniculatus, which is abundant in this particular meadow, where it proceeded to rub its wings up and down like they do but it was too hot for it to open its wings completely:

Common Blue male
Meadgate Fields Open Space 01/08/2024

There was one skipper left to make it into August - probably a Small Skipper but too quick to catch up with - so, unidentified It was interesting to see the profile of the meadow change over time, especially when it came to skipper numbers and percentage composition. Essex dominated the meadow at the early stages and into the peak time first and second week of July when it was rare to catch up with a Small Skipper. However, they began to be more present as numbers of Essex decreased. And because the percentage of females increased, plus the fact they were all becoming increasingly worn and tatty, it meant identification became increasingly more difficult. It became a relief to come across a male with a prominent sex brand.

Across Baddow Meads I was surprised to see the skippers were still present - I even saw a couple courting - although there very few left now and those that I was able to check were female Small Skipper:

Small Skipper female x 2
Baddow Meads 01/08/2024

I was not finding any Essex Skipper, presuming the flight period had finished, when I came across this one and was reasonably confident that I had come across one - but not 100% decisive evidence either way.

Essex or Small Skipper
Baddow Meads 01/08/2024

On the face of it, it looks like the classic dipped in black ink, especially when viewed from over a metre or so. Even the images would confirm this. But my doubts started as I moved around the side - the undersides were not straw-like and had that more grey-like appearance. However, I have found from experience that this is not decisive. and once again, the undersides of the antennael tips appeared black and on the images viewed on mobile in the field. Okay, I thought perhaps an Essex - but it was quite clear when in the shade and zoomed in that this was indeed another Small Skipper despite the fact the orange undersides were not apparent until viewed at a particular angle:

Small Skipper female
Baddow Meads 01/08/2024

It really does show that in a field of Essex and Small where many of the Small Skipper do not have the bright orange on the underneath of the antennael tips, that 100 % confidence in identification is really difficult. And I think this is especially true at the end of the season.

And then happily I came across 5 male Brown Argus across the large expanse of the River Chelmer flood plain at Baddow Meads - not great numbers but in a few locations:

Brown Argus male
Baddow Meads 01/08/2024

This included at a location where I have not seen one before. It seems their local distribution has increased after a healthy 2023 but that numbers were less than half of those of last year:

Brown Argus male
Baddow Meads 01/08/2024

There continued to be fresh Green-veined Whites specimens:

Green-veined White female
Baddow Meads 01/08/2024

And back home this female Gatekeeper was one of only two of the eight that emerged left

Gatekeeper female
Garden on Meadgate Avenue 01/08/2024

The final sighting of note was another Jersey Tiger moth - my fifth of the year. For the last three years I have seen a single one in Chelmsford and mid-Essex, so it seems they are expanding their range further East each year:

Jersey Tiger moth male
Meadgate Fields Open Space 01/08/2024

It is probably the case that we will all have to accept the change to the profile of our local sites as climate change takes its effects on various species with wide ranges of success and failure to adapt to the change in site conditions, including extreme weather events.

[David Lazarus]

I decided to search for blues and browns yesterday [03rd August] as I was worried their numbers were down and there were a couple of places within the River Chelmer flood plain that I had concerned that a few colonies might not survive this difficult year. The sites in question usually have less than 5 anyway.

In the morning I managed to catch up with one of the male Gatekeeper in the garden. There has only been one Holly Blue from the summer brood which is sad but a male Speckled Wood has taken position. I think it could be the end of the Meadow Brown and Holly Blue colonies here and now I will have to rely on creating a series of habitats that will attract passing butterflies next year. Even though the Gatekeeper numbers were only a third of those seen in 2023, I think there are enough to keep going - so sad, trying to reach the 20+ mark after last year's record of 19 but just the 8 which is comparable to 2019-2021 so I need not get too disheartened. Have I done enough to support the colony - a new hedge from whips planted but this won't be suitable for a few years yet - but the open space, I don't know.

Gatekeeper male
Garden on Meadgate Avenue 03/08/2024

What was nice, and in keeping with 2024's ovipositing photographs, another species to add to the list - this time a Small White fluttering around and stopping to nectar on ragwort:

Small White female
Garden on Meadgate Avenue 03/08/2024

So I followed her to the leaves of a Horse Radish where I was able to catch up with her and snapped away:

Small White female ovipositing
Garden on Meadgate Avenue 03/08/2024

And she laid around 6-8 with 2 on the leaf shown in action above:

Small White ova
Garden on Meadgate Avenue 03/08/2024

It was a little overcast, with some sunny intervals, but a bit breezy which made it easier to find a few settled butterflies, such as this Large White. I think they have done pretty well around here like most of the whites in 2024:

Large White
Meadgate Park 03/08/2024

The Green-veined White had darker markings than the Spring - and numbers are quite good in the usual places but this year I do not think they will have a third brood:

Green-veined White
Meadgate Fields Open Space 03/08/2024

On my way to Meadgate Fields there was only a couple Speckled Wood and a Holly Blue, with only a couple each of Meadow Brown and Gatekeeper, so not a great start. There was also a Comma and a Red Admiral in the park.

When I got to Meadgate Fields Open Space things started to improve as I was coming across newly emerged male Speckled Wood at regular intervals with the linear ride and glade in particular showing good signs with a few Green-veined White as well which is to be expected having perfect conditions for them. But nothing else.

Speckled Wood male x 5
Meadgate Fields Open Space 03/08/2024

15 in total with at least one female, if not two, which is pretty good numbers for the size of the space and is comparable with the Spring.

More pleasing was to see a female Common Blue along with the male in the meadow which I think will secure the colony for next year. However, there were still no Brown Argus which is heartbreaking. There were 11 Gatekeeper but numbers are already dwindling, no Meadow Brown left with the Marbled White long since finished. There was one Small Skipper left and a few Six-spot Burnett buzzing around but very quiet now in terms of numbers. I am hoping to see a Small Copper soon.

I then went into Baddow Meads on the hunt for Common Blue, and more importantly Brown Argus, and found that the annual hay cut had taken place. The Common Blue summer brood had only recently emerged and now the flower-rich grassland alongside the Chelmer Road Bridge had been cut so short it reduced the two large patches of lush Bird's-foot Trefoil Lotus corniculata to a flattened plant with nothing else but cut grass surrounding it - far from ideal:

Bird's-foot Trefoil (Lotus corniculata) patches post-cut

I did see one male Common Blue fly by, and a few Meadow Brown and a couple of Gatekeeper. The Marbled White did not quite make August.

But I found the Brown Argus I was looking for, and they were in a little group of 6 males so a bit of a relief even if numbers were severely down:

Brown Argus male
Baddow Meads 03/08/2024

Then I had the usual test of identifying the remaining skippers, and they all appeared to be Small Skipper - females and very worn - half-a-dozen at most. One even took advantage of a garden escapee:

Small Skipper female
Baddow Meads 03/08/2024

And another on the Ragwort which iRecord Butterfly app identified as 99% Essex Skipper from this view - but it was Small Skipper with dark brown undersides of the antennael tip:

Small Skipper female
Baddow Meads 03/08/2024

So a reasonably successful afternoon despite low numbers - a female Common Blue and a thriving, if tiny, Brown Argus colony.

[David Lazarus]

A species focus on the Wall Brown in South Essex: status - Priority Species

As in many places throughout the UK, the Wall Brown has seen a dramatic decline in Essex in recent years. The distribution has seen a severe reduction with local extinction at inland sites where they were once common. Essex is an agricultural county. With the change to intensive farming over the last 70 + years and the increase in new developments on green land, plus the destruction of habitats, notably field margins adjoining hedgerows, the Wall Brown has suffered to the point where we could question whether it will ever recover. Is the Wall Brown lost to inland sites? Has it been pushed to the brink of extinction outside of its current range along the Essex coastline?

We all agree that 2024 has been a difficult year for butterflies in general, and most notably for habitat specialists. Here in Chelmsford, as a person who regularly goes out in the field to collect data, analyse habitats, and observe what is going on, it is heartbreaking to see the continued decline in numbers. Notably for me at the Essex sites I visit, Meadow Brown and Gatekeeper numbers are down. So what about another brown - the Wall Brown?

In recent weeks I have been coming across a lot of tatty Wall Brown. What is interesting for me is that they are appearing at the same places that I observed them earlier in the year. And more importantly these places are INLAND. It got me thinking. I thought I would do a little bit of research to have a look at the trends for Wall Brown in distribution and numbers throughout the South Essex Vice County.

I am restricting my analysis to the data collected on iRecords, which for the Wall Brown goes back to 1976 in the Vice County of South Essex. In the period for sightings recorded on or before 2013 there were only 151 sightings. These were restricted to 3 coastal sites only - Two Tree Island and Benfleet Downs both on the River Thames Estuary in the Leigh-on-Sea area; and one more site Barking Riverside, in East London, which has only one recorded sighting in 2011. Basically, two areas very close to each other on the southern coastline of South Essex. That is the place people have visited to record Wall Brown numbers in the whole of the South Essex Vice County and nobody came across a single Wall Brown inland and recorded it on iRecord in the period from when records began in 1976 to 2013

Wall Brown distribution map for South Essex recorded on or before 2013

The following are the distribution maps for subsequent years showing the annual sightings recorded on iRecord for the Wall Brown in the Vice County of South Essex:

Wall Brown distribution map for South Essex 2014
3 records

Wall Brown distribution map for South Essex 2015
22 records

Wall Brown distribution map for South Essex 2016
15 records

Wall Brown distribution map for South Essex 2017
40 records

Wall Brown distribution map for South Essex 2018
10 records

Wall Brown distribution map for South Essex 2019
30 records

Wall Brown distribution map for South Essex 2020
40 records

Wall Brown distribution map for South Essex 2021
37 records

Wall Brown distribution map for South Essex 2022
82 records

Wall Brown distribution map for South Essex 2023
125 records

Wall Brown distribution map for South Essex 2024
123 records so far

In comparison to the distribution of the Wall Brown from 1976 to 2013, the last 10 years 2014-2024 has seen an expansion of the range of the Wall Brown inland and further north within the Vice County of South Essex:

Wall Brown distribution map for South Essex 2014-2024
527 records

On the face of it this seems great news.

But I am not entirely convinced that this is great news. Firstly, we have to bear in mind the dramatic decline of numbers and distribution of Wall Brown in South Essex in the first place. So these records and the distribution maps generated from them represent the Wall Brown's recovery. But does it? There are certainly more people adding records of their sightings these days as mobile apps make recording easier. Are more places being visited by more people who are interested in recording their sightings? You might also add that Wall Brown sightings can be quite easily overlooked with assumptions made that they are 'just' Meadow Brown, Gatekeeper, or even Speckled Wood.

Are there more Wall Brown in South Essex or are more experienced recorders monitoring numbers and distribution more effectively? Perhaps the Wall Brown were always inland within South Essex but at low numbers that remained unseen and/or people were unaware that they were there.

I would like to think that changes in habitat management especially when it comes to the aforementioned field margins and hedgerows have contributed in the Wall Brown's attempt to recolonize areas that were lost. I have been delighted to come across the ones I have found and would like to think that in at least a couple of places at Langdon Country Park near Basildon and the Danbury Common and Ridge Nature Reserves near me in Chelmsford, that they have always been there but have gone unrecorded. I am hoping that this is the case elsewhere in North & South Essex and that I will find them.

And if this is a recovery of the Wall Brown in South Essex, I look forward to monitoring the continuation of this in the coming 10 years or so. I would also like to see improvements in the results of current conservation work practices, and to see more projects contributing to the restoration of lost habitat, and the enhancement of what remains, resulting in greater numbers of Wall Brown at more sites across the county.

All images were produced by using Open Street Map and iRecord data. Any mistakes are mine alone for which I apologise.

[David Lazarus]

Wall Brown sightings inland within South Essex continued

I have been fortunate to locate Wall Brown inland including at sites where they have not been recorded before on iRecord. Their app. even 'warns' that this butterfly is not recorded in your area. I think they will need to update their app. as Wall Brown will continue to expand their distribution inland. Hopefully they will find suitable habitat if conservation work is carried out and farmers are urged to set aside land especially south-facing woodland edge field margins.

Here are the locations where I have seen Wall Brown in 2024:

Wall Brown 2024 sightings - South Essex

This week I plan to add to this distribution map by visiting Walton-on-the-Naze, Wallasea Island, Hadleigh Castle Country Park & Two Tree Island, and if the weather remains good, perhaps Ramsey Marsh as well - a tour around the Essex Coast by public transport and walking miles.

To add the details, my first Wall Brown sighting in 2024 was at One Tree Hill within Langdon Hills Country Park on the first of May during the time I was searching for the elusive Essex Grizzled Skipper - the Wall Brown was an extra bonus and a complete surprise [actually it made up for 8 hours of fruitless searching for the elusive Grizzlie]. Only a record shot though as it was very active and would not settle for me:

Wall Brown female
One Tree Hill 01/05/2024

I returned after some poor weather to continue the fruitless search at One Tree Hill on the 11th May. It was a fantastic day, hot with plenty of sun - perfect for Grizzled Skipper - and what joy I had when there were five fresh-looking Wall Brown along the ride above Johnson's Meadows West, including a beautiful female. And this time they were very amenable to an iPhone 11 Pro stuck in their face:

Wall Brown female
One Tree Hill 11/05/2024

Wall Brown male
One Tree Hill 11/05/2024

Again, I visited One Tree Hill on the 19th May to find three of the five Wall Brown still going about their business as well as the elusive Essex Grizzled Skipper categorized as Grizzled Skipper Male 003 - just the 12 hours plus to find one tiny butterfly within a huge hay stack Happy Days!!! Plus 130 Small Heath - a very successful site survey that I was very proud of. Back to the Wall Brown:

Wall Brown
One Tree Hill 19/05/2024

Wall Brown male
One Tree Hill 19/05/2024

Grizzled Skipper Male 003
One Tree Hill 19/05/2024

okay - slipped in Grizzled Skipper Male 003

And now we come to the first of the surprising moments. Very much inland during a visit to the Danbury Ridge Nature Reserves in mid-Essex close to my local patch at Chelmsford. On the 20th May while walking through Pheasanthouse Farm NR I came across a Wall Brown - it was very much a wtf moment I had to at least get a record shot but it kept flying around the place, landing but moving before I could get there, and this went on for a good half-an-hour. Finally, very much from long distance hoping I could creep up to get a more professional happy snap, I at least got something:

Wall Brown male
Pheasanthouse Farm 20/05/2024

And if this wasn't surprising enough, 4 days later while on a visit to Hockley Woods on the 24th May there was another one - what is going on, I thought:

Wall Brown male
Hockley Woods 24/05/2024

On a final Grizzled Skipper search to One Tree Hill on the 6th June, after some really awful weather, during which I had to accept that we only had 5 Grizzled Skipper sightings in 2024 , I at least came across my final Wall Brown of the spring and early summer:

Wall Brown male
One Tree Hill 06/06/2024

And now I come to this month's sightings in August 2024. The first sighting in late summer was on a farmer's lane between Northlands Wood in One Tree Hill and Great Sutton Wood where it was perching on an old wooden gate:

Wall Brown male
Northlands Wood 13/08/2024

A couple of days later at Hockley Woods on the 15th of August there was another tatty male in the field margins which had plentiful nectar-rich flowering plants still while everywhere else in Essex seems to have had a close shave removing significant communities of butterflies at the same time:

Wall Brown male
Hockley Woods 15/08/2024

And after another couple of days another sighting at Rainham Marshes while searching for the elusive Essex Brown Hairstreak - I seem to be searching for other species when I come across a Wall Brown as a consolation prize. No Brown Hairstreak on this occasion but another tatty male, making it three tatty males in six days. This one should be classified as half a Wall Brown:

Wall Brown male
Rainham Marshes 17/08/2024

And finally, the Wall Brown that really started me thinking about how the distribution of the Wall Brown is expanding northwards and eastwards into mid-Essex from the coastal stronghold of Leigh-on-Sea. The first recorded sighting of a Wall Brown in Danbury Common:

Wall Brown female
Danbury Common 19/08/2024

In 2023 there were 54 sightings from the 01st of August to the 01st of October with the majority of sightings at those sites I am intending to visit this coming week.

2024 has proved to be the best year for the Wall Brown butterfly since records were recorded on iRecords database despite the weather conditions that have reduced numbers and distribution of many of the UK's butterfly species. Another success story to cheer our hearts with the Heath Fritillary and the Peacock that had over-wintered. Not all bad.

[David Lazarus]

Butterfly sites in South Essex

Below is a map showing the location of my favourite sites within the vice-county of South Essex visited during 2024 where I completed site surveys and target species counts:

Important butterfly sites within South Essex

Target species counts were taken at the following locations:

Grizzled Skipper can only be found at site 1 Johnson's Meadows
Heath Fritillary can only be found at sites 2 Hockley Woods; 3 Pound Wood; & 4 Hadleigh Great Wood
Brown Hairstreak can only be found at 5 Claybury Park & 6 Rainham Marshes
Wall Brown can be found throughout the length of the Essex Coastal Saltmarsh & River Estuaries including 6 Rainham Marshes; 7 Thames Estuary Path; 8 Canvey Wick; 9 Benfleet Downs & Two Tree Island; 10 Wallasea Island & the River Crouch Estuary; 11 Bradwell Waterside, Denbie Flats, & the River Blackwater Estuary
Purple Emperor - White Admiral - Silver-washed Fritillary can be found mostly at important sites within North Essex but also at Danbury Ridge Nature Reserves - mostly 13 Lingwood Common & 14 Little Baddow Heath; as well as the South Essex Woods - 2 Hockley Woods, 3 Pound Wood & 4 Hadleigh Great Wood; and some sites within Langdon Hills Country Park & Epping Forest not shown.

[David Lazarus]

Butterfly sites in North Essex

Below is a map showing the location of my favourite sites within the vice-county of North Essex visited during 2024 where I completed site surveys and target species counts:

Important butterfly sites within North Essex

Target species counts were taken at the following locations:

Purple Emperor - White Admiral - Silver-washed Fritillary can be found at 1 Great Holland Pits; 4 Stour Wood; 5 Friday Wood & Cherry Tree Lane; 6 Hatfield Forest

There is much of North Essex that I have not yet explored.

[David Lazarus]

Top 5 butterfly sites within Essex

Below is a map showing the location of my top 5 favourite sites within the whole of Essex visited during 2024 where I completed site surveys and target species counts:

The five locations for seeing butterflies within Essex
that gave me the most joy during 2024

Johnson's Meadows and Hatfield Forest were by far the most overall best sites I visited in Essex during 2024 with so many amazing experiences and happy memories created. It was a toss up for me between Hockley Woods and Pound Wood - both provided such wonderful moments with the Heath Fritillary during a successful year. The Essex Coastal Saltmarsh and the extensive trek around the sea wall and coastal paths were perhaps the most rewarding experiences for me during 2024, with the unexpected surprise of a butterfly haven along the Thames Estuary Path near East Tilbury that took first prize. And then I wanted to choose a local site - Baddow Meads & the River Chelmer floodplain and the Danbury Ridge Nature Reserves were the standout locations with Lingwood Common coming out on top because of finding the Purple Emperor congregation trees.

There were so many locations that missed out, most notably Great Holland Pits and Friday Wood & Cherry Tree Lane which are outstanding places to see butterflies within North Essex; and Claybury Park/Rainham Marshes for Brown Hairstreak; as well as Wallasea Island and Benfleet Downs which are also outstanding places to see butterflies within South Essex.

There are probably lots of other places within Essex that I have not discovered yet. 2025 will be a busy year for me with numerous visits to my top five sites planned, and depending on the time of year a great deal of tracking down target species and monitoring their numbers as well as the health of the habitats they occupy. A lot of work - but super rewarding

[David M]

I love how thorough you are, David, and yes, 2025 ought to be rewarding given the hard yards you've put in this year.

Good luck!