The whole of Nottinghamshire featured in this event, but by the time word had got round, most had completely missed out on what was a truly remarkable event. Fortunately, this event is likely to occur again in August, as butterflies resulting from the invasion, emerge and begin to return south again.

The last time a large return migration event like this took place was back in 2003, which followed on from a much less spectacular Spring arrival. August 2009 is therefore, likely to break all modern records.

The event had been largely predicted earlier this year, with huge counts of Painted Lady pupae noted in fields around the Atlas Mountains in Morocco. Comments were made on the Migrant Recorders Network Discussion Yahoo Group at the time and in early April, large numbers of Painted Ladies started to move through southern Spain. Painted Ladies (mostly singles and twos) began being seen in the UK during late April and early May. More substantial movement was noted through Cornwall during the second week of May and along the southern UK coast on May 21st. Corresponding to this, was a single Painted Lady at Eakring Flash on May 22nd, was the earliest ever recorded from here, but there was no coverage possible at Eakring on May 24th/25th, during which millions of Painted Ladies arrived. We did note them passing through wooded glades in Sherwood Forest, but had no idea of the scale of the event at the time.

Movement over the next few days was limited through unsettled and windy weather, but began again when warm, sunny weather returned. We were once more in Sherwood Forest when a constant stream of Painted Ladies were moving north on May 28th, following every contour of the trees and ground. Purposely moving to the open farmland of Red Hill at Eakring, we began to systematically count Painted Ladies as they moved over a cornfield. Counts were made during the afternoons of three consecutive days and the results are shown in the graphs below, along with written accounts made at the time.

Movement in the south of the UK was also still strong on May 28th, but decreased dramatically the day after and there were no large counts reported from southern areas after May 28th. It was interesting to see that the main wave of Painted Ladies was obviously continuing to move north through the country and observers in Yorkshire and Lancashire were to see their highest numbers on May 29th and 30th.

A total of 1 414 Painted Ladies moved north through Eakring on the afternoon of May 28th. We watched across a 100 metre stretch of open field between 15:20 and 17:20h, completing counts every five minutes. There were three five minute periods when three figure counts occurred, with a maximum of 140 Painted Ladies through between 15:50 and 15:55h.

There was some evidence that numbers were higher when it was sunny. Even given the Cumulus nature of the cloud this afternoon, periods of cloudiness were brief, but movement was significantly lowered and several Painted Ladies were noted being tempted to halt movement by dropping into the cornfield.

Painted Lady butterflies continued to move through Eakring on the afternoon of May 29th, although in much reduced numbers than the previous afternoon. Movements today were generally straight WNW, but there appeared to be a definite south-easterly movement into the wind today, something that was not noted yesterday. A total of 728 Painted Ladies were recorded.

We again made counts of five minute periods from 14:25-15:50h. There was also a distinct decline in movement throughout the watch. Numbers peaked between 60 and 70 per five minutes, between 14:35 and 15:05h, dropping to between 38 and 45 from 14:55 and 15:30h. The last four five minute counts produced counts between 12 and 21, so there was a clear drop in movement.

Painted Ladies still continuing to move through Eakring this afternoon. A one hour sample count, again divided into five minute periods, produced a maximum of 24 through between 16:05 and 16:10h.

The majority of butterflies were heading more or less into the wind today and going north-east, but there were smaller numbers which continued to fly west. 191 through in an hour, would still represent an amazing Spring count, away from 2009.

It was widely expected that there would be much larger numbers during the Autumn, than there were in Spring. This turned out not to be the case, but some movement was evident in early August and perhaps much earlier than would have been expected. In fact, it was in line with a larger southerly movement, which occurred back in 2003, although circumstances were different as there had been no massive Spring influx into the UK.

At Eakring, the first were noted on August 6th, when three went south. This was followed on August 8th by a further 12 south, but movement proper, seems to have commenced on August 9th and featured several other species.

Totals for a two hour count on the 9th included 93 Painted Lady, 109 Large White, 47 Peacock, five Small White and three Red Admiral all heading south-west across open fields. Movement for all species was direct. Peacock is not a species known for it's migratory tendencies, but was seen in numbers, during similar movements in August 2003.