East Lothian Butterflies 2019 Part 1

There was a very clear correlation between the weather and number of butterflies seen in East Lothian in 2019. After a reasonably mild winter there was an unseasonably warm week at the end of February with temperatures reaching 16 degrees. Then it was cold again until the end of March. At the end of April we experienced an even warmer week with temperatures of 26 degrees. However, we still experienced a few hard frosts in May. The remainder of the year was quite reasonable, but it was interspersed with very heavy rain showers. The butterfly season ended abruptly at the end of October when the weather turned cool and wet.

Other than a couple of hardy Peacocks that appeared in January, the warm week in February brought out a flurry of species. We had seen seven species before the end of February, which must be a record for East Lothian. Things then went very quiet until the third week in March when the butterfly season truly started. Most species did very well in 2019, probably as a result of the very good weather in 2018 allowing the early stages of the butterflies to survive in good numbers. However, from July through to September there were occasional very heavy periods of rain which had a dramatic impact on butterfly numbers.

Despite having fewer people recording butterflies than the last few years we had a record 20,598 butterflies recorded in 2019 (16,875 in 2018). This was helped considerably by the enormous number of Painted Ladies that arrived on our shores in June and July, but even without them we had almost as many butterflies as in 2018.

Peacock, Aglais io

The first butterfly recorded in East Lothian in 2019 was a Peacock seen at Aberlady Local Nature Reserve on 11th January. A second Peacock was seen at Levenhall Links three days later. Peacocks have been recorded in increasingly high numbers over the last seven years, with 2019 being the best year yet. Numbers peaked in mid August, but then dropped very quickly again to single figures by the start of September.

Small Tortoiseshell, Aglais urticae

The Small Tortoiseshells waited until the warm week in February to show, with the first record being on the 17^th. They have been declining in numbers over the last few years. However, 2019 saw a bit of a revival in numbers when the new generation emerged towards the end of July. As usual, they quickly disappeared with many of them heading into hibernation surprisingly early in the season.

Comma, Polygonia c-album

The number of records of Commas has gradually been increasing since they were first recorded in East Lothian in 2001. However, they declined significantly 2016 presumably as a result of the lousy summer. Since then they have been picking up and in 2019 the recovery continued. The first Comma was seen on 25th February and, like the Small Tortoiseshell, their number peaked for a week at the end of August and then very quickly they disappeared. It will be interesting to see how many return next spring after their hibernation.

Painted Lady, Vanessa cardui

The big story of 2019 was the arrival on our shores of an enormous number of Painted Ladies. These came in two waves. The first at the beginning of June when we were amazed at the number of Painted Ladies being seen. But that was nothing compared with the number that arrived at the end of July when they were seen in their hundreds. Some of these would have been the young of the previous arrivals, but most of them were seen flying in from the sea. They were also noted flying in a very

definite westerly direction and records were received from all over Scotland including the Outer Hebrides.

I was interested to learn that Painted Ladies had done similarly well in the USA in 2019. So, on both sides of the Atlantic conditions must have been just right throughout the lives of four or five generations of butterflies.

I received records of 5395 Painted Ladies in 2019, a big difference from an average of about 80 over the last six years.

Speckled Wood, Pararge aegeria

The exceptionally mild week in February also brought about a remarkably early record for the Speckled Wood. In fact two were seen on February 26th basking in the sun on the coast at Prestonpans. There was another record on 22nd March. We normally wouldn't expect to see a Speckled Wood here until the middle of April, which is when we started to see them again in 2019. I can only imagine that the three early records were individuals that had benefited from the long summer of 2018 and had formed chrysalises late in the autumn.

The spring populations appeared in higher numbers than in previous years and I was expecting to see bumper numbers later in the summer. However, the heavy rains that we experienced appeared to knock Speckled Woods quite hard.

There were fewer Speckled Woods recorded in 2019 than in the previous year, but they are still doing well in East Lothian.

Small White, Pieris rapae

After such a great year for Small Whites in 2018 I was expecting to see great things in 2019. And it was a good year, but just not as good a year as last year! In 2018 we had records of almost 3500 Small Whites, but in 2019 we recorded 950. However, this is still good when compared with the average for the previous five years of about 360.

The first Small White seen in 2019 was on the 27th February. A good five or six weeks earlier than we would normally expect. The rest of the season was much as expected with a summer population about five times as great as the spring population.

Red Admiral, Vanessa atalanta

The first Red Admiral record of 2019 was on 27th February. This was most likely an individual that had survived the mild winter. There were a few more records in March and April, but it was the first week of June when they started to arrive on our coasts, about three days ahead of the first wave of Painted Ladies. There was another spike in numbers at the end of August, which could have been the next generation. Red Admirals continued to be seen in good numbers until the end of October.

Orange Tip, Anthocharis cardamines

Orange Tips did very well again in 2019. This was probably a result of the great year they had in 2018. They were fortunate that their flight period was before the heavy showers started, so the weather was kind to them.

The first Orange Tip of 2019 was seen on 31st March, about a week earlier than normal.

Green-veined White, Pieris napi

The first Green-veined White was also seen on 31st March. The spring population was a lot larger than average, with the summer generation just being a little more than normal.

Large White, Pieris brassicae

The Large White has never been as numerous as the Small White or Green-veined White. 2019 was a fairly average year for them, which is a little surprising considering how well they did in 2018. The first record was on 11th April and they were recorded through to the 28th September.

I'll continue with the rest of the butterflies seen in 2019 in my next post.