Fri July 3rd: an 'average' year...

Walked the Knepp Purple Emperor transect this afternoon, for Week 4. Counted 32.

That makes 2026 an average year for the PE here, even if they burn out fast in the coming heatwave (which they may well do).  

They have been very hit and miss here this year - localised and episodic.

Today was my last day at Knepp.  Off home early tomorrow, to work Savernake and elsewhere...

Here's my signing off photo from Knepp - 

 

 

Thurs July 2nd: Hungover...

Struggled to see Emperors at Knepp today. It was too windy, yet again, but the two sap run trees which had been heavily favoured these last few days both drew blank, and most of the favoured male territories were empty too. Sap runs can suddenly switch off.

Conclusion: both sexes got so plastered during the football last night that they took the day off, hungover. I can't think of any other explanation...

The best I managed from today was this photo of a female sapping next to a Red Ad on the feeder tree next to the tree platform down Green Lane - 

Tomorrow's my last day here. Need to finish on an almighty high...

   

The Purple Emperor Rescues England

Watched the first half of England v DRC. Decided the cause was lost, so went out Emperoring on bike, listening to the match on the radio.

Both England's goals were set up by the Purple Emperor butterfly. Both goals resulted from magnificent 'tumbledowns' (mated female rejecting a wont-take-no-for-an-answer male). Here's Kane's winning goal -

Interestingly, there are still a fair number of fresh-looking males around at Knepp, and males are still 'sallow searching' (for females and female pupae).  

 

Tues June 30th: Apatura iris in cop

Briefly, as I'm too tired. A pair joined at 4.05pm on the shady leeward side of a feeder oak, just 25' up, after meeting in flight. No courtship (he didn't even ask her name...).

They remained together, motionless, wings closed, for a marathon 4 hours and 2 minutes. The average duration prior to this observation was 3 hours 42 mins, from a sample of 19 pairings (now 20). Gentlemen of England, Ladies even, we are outdone, by a butterfly...

We managed to show them off - and a lot more - to one of Knepp's famous Purple Emperor Safaris (estab. 2014) - 

All previous pairings I've seen have been in the tops of tall trees. Really good to see them so low down.  At one point I saw 6 males and 2 females in a vista by that feeder tree.

Onward!

 

 

Mon June 29th: Knepp Transect Data

The Purple Emperor is now at peak at Knepp. 

Today, I walked the Knepp PE transect. This runs down 2km of oak-lined green lane and takes around 2 hrs 30 mins to walk. Weather conditions were Good, with Emperors nicely active (a wind sprung up towards the end - Knepp is a surprisingly windy place).

I totalled 38, including 5 females. 

That's about par, suggesting that the butterfly is in average numbers at Knepp this year (though way down on last year's stupendous showing, which produced a record individual transect count of 80!). 

However, if another extreme heatwave comes over, they'll shoot over early (as happened last year, and in 1976) - in which case this year will become a below average year...

At last, some of Knepp's oaks are producing sap runs. Both males and female cluster around these 'feeder trees', which means they tend to disappear elsewhere. 

Here's some feeder tree action from 2025 -

  

Sun June 28th: The Wind Returns...

Far too windy at Knepp today, again, after a quiet and productive day yesterday. Most of the male territories were unoccupied today, windswept. There was, though, some good activity out of the wind, along east-facing and north-facing edges.

Elsewhere, the Emperor seems to be having a good year in Lincolnshire. Down south, numbers seem at best moderate, but we can't get a reading when it's either stultifyingly hot or blowing a gale...

Here's the wrong Emperor, the Emperor dragonfly, eating a Marbled White - 

 

Sat June 27th: Muggy, Still & Cloudy

Change in the weather, to warm, muggy cloud, with hardly a breath of wind. Perfect Emperoring weather! They love it, and are fully active.

Back at Knepp, after a week elsewhere. People had struggled to see PEs at Knepp during the heatwave, but that changed today: most of the favoured male territories were occupied, with males sailing around joyously, and some females evident. 

Three 'tumbledowns' were seen: descending spiralling flights with "Hi! I'm Andrew Tate" males circling around an "I'm washing my hair tonight" mated female. At the last second she will do a U-turn, hoping that he will crash land and smash up his top range performance motor. This behaviour was first observed by KJ Willmott at Bookham in 1983 - Heslop never saw it, nor me till Knepp. It's common at Knepp during the second half of the flight season.

Here's a female basking in a sloe bush yesterday -

And here's a more typical view of a female (again, yesterday): they spend hours sulking in sallows, all but out of view - 

Today, though, Sunday 28th, the wind has returned. Leeward, leeward and leeward...