Big Bang Day in Fermyn

Oates's diary for 15/7/2013 -

Mon July 15th    St Swithin
Cloudless, still and very hot. 27C. Hazed over a bit after 6pm.
Lady & Souther Woods, Fermyn Woods. 8.10-3.15 & 3/50-7.10.
Stupendous day in which I saw a probable 127 individual Purple Emperor, including one ab lugenda male, a weak ab iolata briefly (male) and witnessed a pair in cop, from start to almost finish (she was one of only 3 females seen). Purple Emperor started here on Thurs, there was a good emergence yesterday but today was Big Bang Day, the main male emergence day, and the weather was perfect – possibly a bit over-perfect as they were still active when I gave up, expired, after 7pm. It was so hot that they had a modest siesta mid afternoon, from 3.00-5.00 when they became active again, with a fair few descending to the rides for afternoon tea. For the record, I met up with Doug Goddard & Andy Wyldes and John Woolmer.

Males were already up and about, high up on the trees, when I entered the woods just after 8am. I had 9 sightings of at least 7 individuals down the W Ride, 8.12-9.05. Initially they were all high on the oaks where they’d roosted, but they gradually started flying lower and lower. Some inspected pine trunks for sap.

Just after 9am they started descending to the rides in search of moisture and Lord knows what else – the W and E rides had been quite heavily baited by various folk, mainly with diluted shrimp paste, but plain water proved almost as good in this heat. Sadly, I didn’t manage to keep a tally of the number I saw down on the ride surface today, but it was at least 50. All were pristine. My first grounded male was at Poplar Corner at 9.10, then 4 down along the heavily baited N end of the E Ride ca 9.15, and several others shortly afterwards.

Chaos with a capital C descended at 10.10 when a group of us spotted a pristine ab lugenda male down on the E Ride N end, between Poplar Corner and the E Ride Summit. But he was wary and short off southwards. I followed and flushed up 4 grounded males before I lost him, then got distracted by 5 males down on diluted shrimp paste baits at Log Cabin T Junction. Later Doug Goddard got a reasonable photo of what may well have been the same male, down on the W Ride mid morning.

Between 10.15 & 10.30 I saw 15 males down or low between Log Cabin and Poplar Corner (ca 300m). I then counted 22 in 30 mins along the ½ mile W Ride, of which 20 were down on the ride. At 10.50 I saw a weak ab iolata male in flight along the E Ride, but lost it amongst a couple of type males. Around this time I twice saw a pristine male with very weak purple scales (all angles) down on the ride at E Ride Summit. Neil reckons these un-purple males purple up later in the day. I’ve bred this butterfly for nearly 40 years and have never known them change colour. This male was seen again in the same spot at 6.41.

From 11.30 males were on the ride surface in much lower numbers, and were actually outnumbered by butterfly photographers. By noon only the odd male was down. Most had gone sallow searching, and I saw a lot of that (from ~10.45). I searched some of the territory rides, seeing 5 males along High Seat 382 Ride, including 2 sallow searching. One was on the deer seat itself.

At 1.08 I spotted a male following a female 18” behind her high over the entrance to Lyveden Way Ride, but they flew off into tall maiden oaks and were lost. A classic courtship flight. I’m sure they paired there.

En route up to HS 381 Ride ca 1.15 I passed 2 males and 1 female down on the ride, and saw 2 more males sallow searching. HS 381 Ride then produced 9 males, including two pairs of battling males in the usual favoured territories. Shortly after I found a couple of males in the Scots Pine Territory by E Ride Summit. This territory is only used in very hot and still weather.

I then went to see what was going on over the Lady Wood Head poplar stand. There seemed to be 4 males active on territory (I saw 4 in flight at once, but only clashes of two at a time). Then, at 2.38 a female flew along the poplar line and was immediately accosted by first one then two males, whilst two other males decided to clash and chase nearby. She immediately led the two to the end of a Scots pine spray some 10m up, above the ride opposite the middle of the poplar line, in 70% shade, and instantly joined with one male – whilst the other tried to muscle in. The pair in cop settled wings closed, motionless apart from being disturbed by the 2nd male, who eventually calmed down and settled wings closed nearby. He skulked off at 2.56. Previous pairings I have watched have lasted for ca 3 hrs 45 mins, so I left them to it just after 3, intending to return at 5pm.

I decided to return to the cottages, for afternoon tea and a shower, as activity was quietening right down. En route I saw 3 more males down on the W Ride, including a massive one which probably equated to Heslop’s ab maximus – only I’ll never know for the criteria for determining it as maximus is whether it fits on a 3½” setting board or not.

I returned at 5pm. The pair in cop was still in cop, motionless in the same spot, wings closed, at 5.12 but sometime between then and 5.23, when I next checked, they had separated. So the pairing lasted a mere 2 hrs 33-45 mins – and hour short of the norm. Maybe they got disturbed?

Males started to descend to the ride again at 5.15, but just before 6pm it started to haze over, so they took to the trees again. I saw 3 chasing over the Poplar Corner Oaks at 6.25, whilst looking for Purple Hairstreaks there.

At 6.41 the pristine unpurple male I’d seen twice during the morning around E Ride Summit descended again, looking unchanged. Fermyn is the only place I've seen this odd colourless form.

It hazed over properly around 7pm, when I saw my last iris of the day – at Neil Corner, where I’d seen my first. Shortly afterwards I gave up and went back to the cottages for a meal with Japanese artist friend Tomoko Take.