Sunday, July 30, 2023

Sat July 29th: Still Going...

I returned to Savernake today, and managed to see 8 more males. It was sunnier but much windier, which meant that territories on higher ground were scarcely occupied. I found two new territories on lower ground, one which held two sparring males. 

This might be my last Emperor of 2023 -

'In my end is my beginning...'

They are still going at Knepp, just. 4 were seen there yesterday, after a gap of several days.


Friday, July 28, 2023

Fri July 28th: Still Partying in Savernake...

A cloud-spoiled afternoon along Three Oak Hills Drive in Savernake Forest gave sightings of 9-10 males in four known territories. All bar one were torn and worn. 

Ten minutes of sun at The Dead Beech Glade produced a squabble of three males, and I also saw three in a vista at another territory further on from The Column.

Incredibly, two perched 1m apart. Here's the pic, taken from some distance below (Sav's Beeches are 90-120' tall). Spot the Emperors -

And here's a lone male perching - 

As usual, none was seen in The Column glade, which is only a secondary territory. Yes, that's where everyone goes to see iris in Savernake, and they occasionally do quite well there, but they walk past the best primary territory - the Dead Beech Glade at W3W gold.subtitle.applies - 

Depending on the weather, there's a few days left in Savernake...  

PE seems to be over now at Knepp - no sightings there since Tuesday 25th.

Monday, July 24, 2023

Mon July 24th: Final Sightings...

The Emperor season was hit by another bout of rain on Sat 22nd. I managed to see an OAP male over one of the favoured feeder tree oaks at Knepp an hour before the rain began. Red Admirals were feeding on the sap bleeds there. 

The Red Ad is, of course, staging a mighty bold bid to win Butterfly of the Year - and with a homegrown autumn brood to come...

Oddly, I spotted a male Brown Hairstreak perched on one of the favoured male perching sprays as steady rain arrived.

Since then, there have been single sightings at Knepp on Sun 23rd and Mon 24th, a sighting of a female in Bernwood Forest on Sun 23rd, and sightings on Billa Barra Hill in Leicestershire on Sun 23rd and Mon 24th.  

The race is on for the last iris of the Great 2023 Season (which wasn't great in East of England region, but was just about everywhere else, and was stupendous in Central Southern England). 

This Blog, of course, carries on all year round, covering adventures with the immature stages...

An unusually large number of eggs should have been laid this season, and larvae should be relatively numerous this late summer and autumn. Therefore, this is the year in which to look for new populations by searching for the immature stages. Herefordshire, here I come... ... ...



Friday, July 21, 2023

Fri July 21st: Herself

It clouded up at 1pm today, just after PEs had become active (late in their season they take the mornings off...). By 2pm it was very dull, by 3pm all species were grounded.

I watched a middle-aged female feed for nearly an hour on an oak sap bleed (the Hornets had stopped flying, too cool for them). Here she is -

She then fell off, before flying off upside down, careering across the glade and crashing onto a bramble patch, pissed. Her she is -

The forecast foul & abusive weather will end this season, ridiculously early (but sooner rather than later the Purple Emperor season will start in May)...

Thursday, July 20, 2023

Thurs July 20th: Final Hours at Knepp

I struggled to see 5 PEs at Knepp this afternoon, though it was rather too cloudy: one male in reasonable condition, two geriatric males and two females, one very much in her final hours. Here she is - 

I may not see any tomorrow...

What do you do when the party's over?

Find another party, and the Brown Hairstreak is just starting. Here's Knepp's first of the year, a male high up on Field Maple, this morning -

Wednesday, July 19, 2023

Wed July 19th: Slip-sliding Away...

The Purple Emperor season at Knepp, W Sussex, continues to slip slowly away, though there is still a few fresh-looking females around, and even the odd male, but they have become highly localised and intermittent in appearance. Here's one of today's males, active on the feeder tree oak in the SE corner of Bentons Gorse (for those of you who know the place) -


The BC Glos branch butterfly WhatsApp group today featured a photo of a freshly-emerged female being courted by a middle-aged male - in my home parish! The season is still going strong there...

Tuesday, July 18, 2023

Tues July 18th: Season Ending at Knepp...

As I feared yesterday, the 2023 PE season is ending rapidly at Knepp. It also sounds as though they're going over fast in Alice Holt Forest too, and probably elsewhere in central southern England.

Last weekend's gale was too much for them, and for the midsummer Hairstreaks...  They roost in the canopy, not on trunks and limbs - and get shredded.

I struggled to see 24 at Knepp today, which sounds a lot but isn't considering how big the population is and also that I know exactly where to look (where the male territories and sap run trees are). 

Just 8 were seen on the PE transect, down from 30 last Thursday.

The males now look like this -

Today's photo, of a very old and lethargic male down Green Lane. 

Most females are equally worn and torn, though I was pleased to see these two middle aged girls sapping together today -

Of course, it ended in handbags...


Monday, July 17, 2023

Mon July 17th: Counting Survivors...

Back at Knepp today. It was rather too windy (yet again!) but I managed to walk the PE transect. This totalled only 10 (including 3 females), down from 30 in less than ideal weather last Thursday. 

Allowing for the wind, this suggests that numbers may be down by 50% since just before the St Swithun's Day gale... 

But I'll find out tomorrow, when I'll have another, proper stab at the transect - it's supposed to be sunny, with only a light wind... ... ...

Males weren't holding territory before 2.30, probably because they were busy feeding up.

All told, I saw 20 PE today, most of them females. The majority were feeding up on oak sap and were torn and worn. None was in good condition - 

You might think that PEs would have the sense to roost out gales on the sheltered side of branches and trunks, but most try to roost in the oak sprays - and get shredded. 

My feeling, and I'll confirm tomorrow, is that there may well be less than a week of the season left at Knepp. Don't travel far to visit Knepp for PEs, you're too late: come next year instead.


Sunday, July 16, 2023

Sun July 16th: Vile Again...

Another rubbish day in the western fringes of the Empire, though the wind died down to Moderate strength. I'm heading back to Knepp tomorrow, where the weather's better.

Great to see a male high up over a veteran oak along the lane through Flisteridge Wood in the Forest of Braydon in NW Wilts, just before the sun was lost. This is the first record for this wood, though  another was seen recently in another of the Braydon woods, Webbs Wood (where I've previously found the odd larva). It's so hard to turn up small colonies...

The big news from today is that iris has at last been found in Wyre Forest, on the Worcs-Salop border - one male, found dead in a conservatory. This is the first record from Wyre, ever. It's by no means the first record of an Emperor being found dead in a conservatory.  

Doubtless some bright spark will say this was an introduction. Yesterday I received a didactic Tweet stating that all the Norfolk records result from introductions. Sorry, but I don't believe that, and would like to see the evidence... This butterfly is not that easy to breed, especially in the numbers necessary to establish a colony.  

Finally, here's a photo of iris feeding on banana skins, in the ecology students' compound at Knepp. This is only the second record I know of a Purple Emperor feeding on bananas, and like the first, it's a female -

St Swithun's Day 2023

 This time last year our Purple Emperors were sweating out the beginnings of the record-breaking mid-July heatwave, which saw 40.3C on July 19th...

Yesterday, St Swithun's Day, they were forced to hunker down and sit out a fully-fledged autumnal gale...

When the wind dies down, we will find out how well they have survived.

The survivors will be very hungry. Make for the sap run oaks...

Friday, July 14, 2023

Purple Emperors on Oak Sap

Emperors and Empresses feed, almost addictively, on small sugar-rich bleeds from distressed veteran oaks, especially during the second half of the flight season and in challenging weather conditions. 

Heslop called favoured trees 'Feeder Trees'. Here's a good one, from Knepp (the left-hand tree) -

The features are usually small whiteish bubbles of discharge, like this -

 Rot hole discharge, like this, are also favoured, but are much rarer -

Big runs of 'black treacle' from wounded trees are exceptionally rare, and dry up quickly. Many formed after the great storms of 1987 and 1990, after trunks twisted and broke in strong winds. Oozes from Noctule bat roosts are also good. 

Hornets, Red Admirals and Commas also visit these sap bleeds, along with a host of flies (hoverflies in particular). Watch for Hornet and Red Ad activity under the oak canopy, and watch them home in on the sap bleed. An Emperor or Empress may well be about...

However, feeding on sap runs is a high risk strategy, as Hornets readily predate Emperors. This is what happened to a large Empress at Knepp, 14/7/23 - 

This is a modern problem. I lived in East Hampshire from the mid-70s into the early 90s, and never saw a Hornet - not even in the long hot summer of 1976: they were common in and around the New Forest only. They colonised Alice Holt Forest during the mid-1990s. Likewise, they were absent from the landscape around Knepp until the mid-90s. 

Also, Heslop (lead author of Notes & Views of the Purple Emperor, published 60 years ago) doesn't mention Hornets at all, despite working the Bentley Wood area (SE Wilts, close to the New Forest) and knowing the butterfly's fondness of oak sap.

Here's a Hornet on a sap bleed -

Here's a photo of happier moments, from 14/7/23 -

Wind and Rain...

The jet stream has jumped south and is running right over the Empire, bringing wind, cloud and rain. Curse and crush it! This is an old-fashioned July...

On Wednesday, I managed to see a male in my local wood back home in Glos, then two males sparring at what is at present the only known reliable male territory in the county (near Daneway Banks, of large blue fame).

Back at Knepp on Thursday, in variable weather, I managed to see 58 Purple Emperors including 15 females. They were desperate to get going, and made the most of any sunny break. 

They were also very hungry and were sapping like mad, like these two females - 

and this torn female - 

They were getting pushed off the sap bleeds by Red Ads and Hornets. A good way to spot sap bleeds is to watch for Red Ads flying under the oak canopy, and Hornets.  The Red Ad is making a big stab at winning Butterfly of the Year...

I managed to cobble together the PE transect, for Week 4 of the season. This totalled 30, but I would have got >36 had the weather allowed. 30 is excellent for Week 4.

They are ageing fast. No good specimens were seen, though some of the females were in reasonable condition. 

The gale forecast for Saturday 15th (St Swithun's Day...) is likely to reduce Emperor numbers considerably. My guess is that the season at Knepp will end around July 25th, though it may persist a little longer at some of the 'later' sites.  

Males have stopped coming down to feed on the rides, nationally, and are now stopping flying during the mornings. 

Finally, great to hear Knepp's Purple Emperor safaris being lauded by Martha Kearney on Radio 4's Today programme this morning (6.55, 14th July). Knepp's been running them for ten glorious years... 


Tuesday, July 11, 2023

News from the North

Whereas the Purple Emperor has emerged in surprisingly good numbers down south, it seems to be having rather a shocker in the northern parts of its realm, and also in much of East of England region. It's hard to tell as smaller populations are difficult to monitor - away from central southern England, many populations are close to or below what IRP Heslop usefully termed our 'observation threshold'.

Confession: this is almost the opposite of what I thought would happen! I predicted, on this Blog, reduced numbers in the Southeast region, due to the impact of last summer's drought on sallows, eggs and young larvae, but a good year in the western and northern reaches of the Empire where there was a bit more rain last summer.

The Empire's western fringes seem fine; e.g. good numbers in Savernake Forest, despite the loss of rideside sallows. 

There also seems to be considerable disparity in the timing of the flight season. The season may only just be getting going in Notts - although the populations there may also have crashed. The first male was seen in Sherwood Forest only on Sunday July 9th, a pristine male.

Nationally, we are having a long spell of poor weather right now - cloud and wind associated with a slow-moving area of low pressure, making this an old-fashioned July. Canopy-dwelling butterflies are very hard to work in windy conditions, even when the sun appears. 

By the time the weather improves, it may be too late for many smaller populations...  Hang on in there and use whatever sunshine we get well...

Monday, July 10, 2023

Doings: Sun July 9th

Rather too windy over much of the Empire. Yet another day for leeward edges, only.

Great to see a photo on Facebook of a pristine female taken at the London Wetland centre at Barnes on July 7th. I visited the Centre in 2017 and felt it was suitable then. 

This butterfly is Everywhere, albeit in low numbers: Look (up, leeward) and Thou Shalt Find...  

A good count in Savernake Forest by Dave Law: 15 sightings along Three Oak Hills Drive including two groundings (suggesting it's still relatively early in the flight season there - Sav's a 'late' site), with six males active in the Dead Beech Glade (halfway up 3OHD on the E side, a much better site than The Column where everyone goes...).  

I saw five at a new site on the edge of Swindon-where-the-shadows-lie, then retired home to watch the glorious end of the Headingley Test Match...

We're still getting rather mixed messages from Fermyn Woods, Northants, with many visitors being rather disappointed. Odd that no aberrations have been reported from there, in a midsummer in which a few 'Black Admirals' and aberrant Silver-washed Fritillaries are being seen, plus a nice aberrant Comma in the West Midlands yesterday.  

In fact, numbers seem rather disappointing north of the Thames generally, with the exception of the Oxfordshire / Bernwood area.  

Low pressure is forecast for this week, which will make things difficult.

Finally, I'm pleasantly surprised by how few sallows died in last summers heatwaves and drought. Here's one from outside Knepp's main area -


Saturday, July 8, 2023

Sat July 8th

A cloudy - but, at last, calm - day, punctuated by a hour's worth of thundery rain around midday. It was supposed to clear up nicely from 2pm, but glimmered and glowered instead. Emperors were nicely active during the glimmers.

At Knepp, the Purple Emperor season is starting to age, as testified by this old boy, struggling to feed amongst the wet grasses, albeit  after doubtless playing a prominent role in the Partygate scandal -  

He'd been to visit the ecology students' compost loos - 

But I was shown a photo of a near-pristine male, who'd probably emerged there yesterday, saw a couple of freshly emerged females, and the males are still avidly searching the sallow stands for females. All this indicates that the Knepp season is far from ending - they'll be good for a couple of weeks BUT DON'T VISIT KNEPP AFTER JULY 23rd, they'll be over - and they've stopped feeding from the track surfaces.  

I'm heading back to Glos and Wilts for a few days.

Friday, July 7, 2023

Doings: Fri July 7th

 Knepp. Neil counted 141 there yesterday, finishing at 7.30pm after a good evening flight, including 18 females - 7 of them involved in tumbledown rejection flights with males, and serial violence against Bullfinch, Great Splatted Woodpecker, Wood Pigeon, Chiffchaff and assorted titmice.

I was there too, but didn't do so well and saw virtually no violence. Males were assiduously searching the sallow fields for females during the morning, which suggests that females are still emerging there. They will stop doing this very soon though, and start taking the mornings off. Be warned. And the males have already stopped descending to feed on the tracks. 

Neil and I both walked the Knepp PE transect, 15 mins apart. He and his brother totalled 52 (the third highest count on record, and best after 2018) - but with two counting; I totalled only 43 (one counter) but under-recorded towards the end, as they suddenly conked out in the heat at 3pm.

A lot of feeding on sap runs. Look out for aggregations around veteran oaks, then spot Red Ads and Hornets visiting the small sap bleeds. At one sap run, we had three females perched close by, plus at least two males in the air close by - all had been booted off the sap bleeds by Hornets.

I've no idea what goes on in the mind of the Empress - 

Elsewhere, Rev John Woolmer saw only 8 in 4 hours in the main Fermyn Woods block, 9.30-2pm, and met others who had had similar experiences. His conclusion is that the FC's felling of rideside sallows has adversely impacted on the PE, but maybe the season is more advanced there than we think and the males are stopping descending to the rides? However, Fiona Barclay fared much better, counting 12 in 45 mins.

Great that Ian Surnam turned up PE at Coleorton Hall near Ashby de la Zouch in Leics. This is where Coleridge & Wordsworth had their spectacular bust up...

Nationally, the butterfly is now AT PEAK, and seems to be having a very good year nearly everywhere - the exception seems to be the East of England area and much of the region north of the Thames. 

Thursday, July 6, 2023

Sighting at Southrey Wood

Had an enjoyable hour or so in the company of Richard Smyth at Southrey Wood today, which is part of the Bardney Limewoods National Nature Reserve, located in central Lincolnshire. This is a wood that I have searched and searched and searched for Purple Emperor on many previous occasions, not only this year, but in the preceding two years as well. All prior attempts to find Purple Emperor there have been fruitless, but today we recorded one male, which was low down, only a foot off of the ground, probing a Small-leaved Lime Tilia cordata tree, which was covered in a sticky residue.

The photo shows that the butterfly is extremely fresh, but the left hindwing has curled up on the inner edge near to the body.

My thanks to Richard for making it a very memorable day!

Thurs July 6th: Back at Knepp...

 Back at Knepp. The sun came out to play for the afternoon, but with it came a Moderate SSW wind, which died down after 4.30 to allow a nice evening flight. 

The Emperor is now at peak season here. Females are still emerging (a mating pair was seen today, involving a freshly emerged Empress; another pairing was seen yesterday). 

Males are still active in the mornings, and searching the sallows for girls, but have almost certainly stopped descending to feed from the tracks.  

I'll count them tomorrow, which is supposed to be hot and sunny, and hopefully with less wind. This should be my peak season count. Watch this space...

Here's Herself getting plastered on oak sap today. Note the small white bead - this is what they feed on -

Wednesday, July 5, 2023

Wed July 5th: with a hey-ho the wind and the rain...

Another day largely lost to poor weather. Too cloudy here in Glos, though it looked a bit brighter to the south in Wilts. 

Further east, in Hants and Sussex, good PE activity during the few sunny spells that came along there, though the wind was disruptive - a day for a lot of hanging about and working sheltered east-facing edges, only. 

Males are still emerging and coming down to the ride surfaces in Fermyn Woods, and should still be doing so this weekend - but don't visit after this Sunday if you want to photograph / see males on the ground there, they'll stop coming down.  

They've probably already stopped coming down at Knepp, but I'll find out when I return there tomorrow.  

The good news is that the humungous female I bred, from a larva rescued ahead of ride-side sallow felling by our most beloved forestry body, successfully hatched. I pinned her out 4m up as I didn't want to release her at Knepp, which doesn't need additional Emperors. She was one of four I reared this year, as my 'thermometer': a male and three females. 


Tuesday, July 4, 2023

Tues July 4th: Rain Stops Play

Rain prevented little if any play today over much of the Empire, especially in Gloucestershire, Wiltshire and Hampshire. Some play was possible in some of the northern parts of the insect's range, e.g. Leicestershire, Northamptonshire and Lincolnshire.

Interesting, and odd, that the butterfly still hasn't been seen in Sherwood Forest, Notts, this year... The forest suffered a severe drought last August.

Emperors should erupt tomorrow, after two day's of enforced inaction (weather permitting).

We still don't know what numbers are like in many northern and eastern localities.   

Monday, July 3, 2023


Weep for the 2023 Purple Emperor season, and Pray, hard! 

Purple Emperors, the males especially, are highly vulnerable to being smashed to smithereens by gales. They roost in treetops, like this -

Or worse, hanging from the underside of oak leaves...  If they had any sense whatsoever, they'd roost on the sheltered, leeward side of oak boughs and trunks, but they don't...

Today's Fresh to Strong SW winds will have shredded many an Emperor, and blown many more to Kingdom Come (wherever that is...). 

Teste 2020, when a gale that ran from June 27th to June 29th blasted them away. We were finding maimed Emperors on the forest floor, like this -

We'll find out the extent of the damage when the wind subsides and the weather improves, as is forecast. Fingers' crossed, we may just have got away with it...

On the big picture, there is an unusual degree of disparity between the state of the flight season at Knepp and other sites in the deep south, and elsewhere. North of London it seems still too early to determine what numbers are like (apart from in the Bucks / Oxon woods, where iris is always relatively 'early'). 

Norfolk Empress

3rd of July. Took my first trip out to seek Emperors this season, kept local and visited Foxley Wood. Conditions not ideal but when the sun did shine plenty of activity from Camilla and Paphia but nothing purple until this lady dropped in. I think this is my first sighting of an Empress on the ground. As we say in Norfolk she was a "gret ol big mauther". No males spotted.

Sunday, July 2, 2023

Sun July 2nd: Cloud and Wind...

Another day dominated by cloud (Stratocumulus with sunny breaks) and a moderate to fresh West wind. Difficult working conditions, with a lot of hanging about waiting for a break. Emperors erupted with every break.  

They're starting to get tanked up on oak sap - 

Congratulations to Knepp Castle Estate, pioneer rewilding site and home of the UK's largest known Emperor population, which has now been successfully running Purple Emperor Safaris for ten glorious years! He's today's Safari group getting wowed by His Gloriousity (joined by one or two other folk who were passing by) -

We've got another three days of indifferent weather, then another anticyclonic spell is due to start next Thursday. That will see Peak Season period at most Emperor sites...


Saturday, July 1, 2023

Sat July 1st

A rather too cloudy start to the month at Knepp in Sussex, but Emperors erupted there whenever the sun came out.

Good to see two mating pairs: one just finishing (they got busted up by a rogue male, as happens) in oak at 11.50; the other paired right at the top of a tall Corsican Pine tree at noon, we left them there - 


We are having serious problems with marauding hobbies at Knepp this season. Three of the wretched birds seen today. They took three Purple Emperor males, who attacked them. Here are some bits -

Finally, iterum atque iterum, in these westerly winds, go leeward: work east-facing edges.  Leeward, leeward, ever leeward, even if it's in shade. Emperors gather on the leeward side.