Tues July 8th: OMG, they're going over!

Yes, incredibly, the Knepp Purple Emperor season is very much on the wane, already. 

I did the Knepp PE transect today. I expected to see 25-30, but struggled to count 11 in perfect weather conditions (last week's count was a record 80).  

They've plummeted.

However, it's clear that males aren't occupying territories much in this heat, so I probably under-recorded. 

Also, both sexes are clustering around 'feeder trees' producing oak sap, and there are few of those along the transect route this year.  

One tree in particular is proving immensely attractive, with 2-6 adults (both sexes) ever present. There are 51 people in this photo, admiring Emperors getting plastered on Patrick's Tree -

Also, Empresses have the habit of going shading in hot weather, often for long periods. Here's a middle-aged female who went shading in a bramble bush for over an hour today -

My advice is don't travel long distances to visit Knepp this year, and don't come at all after the coming weekend, they'll be over. If you do come, visit Patrick's Tree, along the White Route (but note that it doesn't function in a SW wind).

Mon July 7th: Windy Sunshine...

A useful drop of rain here in Sussex, yesterday afternoon and again around dawn. Then a few hours of grot. Then windswept sunshine.

The first Purple Emperor of the day appeared with the first glimmer, at 11.07, around the most favoured feeder tree, 'Patrick's Tree'. Prior to then, I'd only seen singletons of Meadow Brown, Gatekeeper and Purple Hairstreak.

Patrick's Tree was on top form, with 2-6 Emperors and Empresses (mainly Empresses) ever present. The highlight was this near-pristine female basking low down on the main trunk -

Elsewhere, the butterfly was hard to find. I've got a strong feeling that the Purple Emperor is very much on the wane here, but I'll find out tomorrow, in better weather (too windy today), when I walk Week 4 of the Knepp PE transect (a 2 mile long single species count with a mighty big recording box, established in 2014. It's Kosher).  

The Knepp season may tail off fast in the coming heatwave...

 

Sun July 6th: Rolling Thunder...

The rolling thunder review at Knepp. No lightning, but myriad rumbles and three hefty afternoon and early evening showers. Some warm sunshine in between though, from late morning.

Good to see a 3-4 day old male feeding on one of the tracks, probably the last to do so this year. Also, a little sallow searching still going on, suggesting that there are still some females to emerge - and we watched a pristine female.  

Again, though, most Emperors and Empresses were feeding on oak sap. This frayed-around-the-edges male had imbibed too much sap, and fell out of the feeder tree to crash land on a ragwort flower. 

 

Note that his tongue was not out and he was not feeding. 

This day half a century ago, the first males of the season were just emerging in the woods to the north of Knepp. Fifty years on, the Emperor started here on June 15th and the season is halfway through...

I used to regard July 6th as National White Admiral Day, when camilla was well out and resplendent. Of course, with earlier emergences they're now well past peak by that day. Here's a somewhat battered male from today - 

Sat July 5th: Gloom, Drizzle & Oak Sapping

Can't remember when we last had a poor day...

But today was grotty at Knepp: as dull as Peterborough (or anywhere else) on a Blue January Monday, with pulses of drizzle.

However, the Emperors carried on feeding in all but the worst of the grot. I managed to see about ten females and half a dozen males, all on or around oak sap feeder trees. 

The place to be was Patrick's Tree -

The best photo I managed was this -

Males have been scarcely using territories all week - except when territories are close to feeder trees. In cloudy weather, when males are on territory, one good way to find whether there's a male present is to send up a drone -

The Emperor sallies forth and attacks the drone, but the downdraught pushed him back, unharmed. Here's a drone (and a distant Easyjet) in a classic canopy gap territory.  

  

 

Independence Day

Back at Knepp today. It took some time to find where the Emperors were - few males were on territory (a bit windy, but even many sheltered territories were empty) and only a few were sallow searching (very soon, they'll stop doing this altogether, and take the mornings off). 

It turned out that most males and many females were busy feeding on the oak sap trees. They are desperate for sustenance in this heat. Here's today's best photo, showing five feeding together - 

This is the first time I've managed more than four in a feeding vista. At one point at saw seven on that short bough length. They are forever being disturbed by fascist hornets when feeding on sap.  

It may be that this weekend's shift to cooler, moisture weather will bring a behavioural change, and males will become more territorial.

Also good to see Purple Hairstreak (in excellent numbers this season) feeding on brambles and ragwort flowers, something they only do in heatwave conditions - 

Other news. Great to hear of a Emperor in the New Forest, a female at Broomy Plain last week. There are very, very few recent records from The Forest, but do people look there?  

Great Emperor seasons are judged by Emperors turning up in unexpected places off piste, like Broomy Plain...

 

3rd July Update

Not too much news at the moment. I've been at home working local sites, with small populations, but am heading back to Knepp tomorrow. The Emperor may be a trifle past peak there... 

Emperor males have stopped coming down to the rides to feed at the earlier emerging sites, like Knepp, though they should be doing it for a few more days at the later-flying sites. This weekend may be the last chance to see them on the ground at places like Fermyn. 

We are hearing of more and more records of both sexes feeding on sap bleeds on oaks in this hot weather. These bleeds are hard to spot as they're small features - not huge splurges of black treacle running down a tree trunk.  Watch for hornet, wasp, greenbottle and Red Admiral activity, as they also love oak sap. Here's a female at sap - 

Soon, probably midweek at Knepp, the males will suddenly stop sallow searching during the mornings, and become afternoon butterflies...

Tues July 1st: Welcome July...

34C in London...  Broiling throughout the Empire.

At Knepp, Neil and Kat spent the day counting Emperors over as large an area as possible. They totalled 283. Now, that's about 100 less than the peak full day count of 2018, BUT the site was far more open then - in particular, sallow thickets are doubled in height since 2018, which greatly reduces sightings of females and sallow-searching males.  

They also walked Week 3 of the Knepp Purple Emperor transect. This totalled 80, by far the highest week count in a single-species transect which has been running since 2014 (the highest count in 2018 was 66). 

Unless the weather collapses badly, and the Knepp Emperors get blasted away - as happened last year - 2025 will comfortably better 2018's transect tally. Then, the six week transect total was 200, we're on 164 already, with three weeks still to come...

On the debit side, as we predicted, males have stopped coming down to feed on the Knepp tracks. Both sexes are getting seriously tanked up on oak sap instead (for those who know Knepp, Patrick's Tree is providing numerous photo opportunities).  

I was in Savernake, where I counted 17 along Three Oaks Hill Drive, including an egg-laying female who seemed to lay one egg on the shaded underside of a vertical leaf (too high up, couldn't see it). I'd expected more than 16 males, but they were suppressed by heat and a total calm. Nonetheless, I think that's a record count for 3OHD, though I've never counted there religiously.   

One male was feeding on The Column (an 18th century excrescence), which they do in hot, calm weather. Here's The Column - 

and here's Himself feeding on it (before he flew off to smash things up) -