East Lothian Butterflies 2020

For the last few years I have been coordinating the butterfly records from the Countryside Rangers and volunteers in East Lothian and then sending them in to Butterfly Conservation. 2020 was a very unusual year in more ways than one. The coronavirus, weather and my move to the Scottish Borders all impacted on butterfly recording.

After a reasonably mild, but wet winter the weather was wonderful from March until June. Coupled with the good summer of 2019 this resulted in a few early records, such as Small Coppers being seen on the coast near Dunbar on 7th April, the earliest record in Scotland.

Unfortunately in early June we had some very heavy showers and the wet and cloudy weather persisted for much of the rest of the year. I am sure the poor weather later in the summer impacted on the number of butterflies we saw.

The Covid-19 lockdown came into effect in March, meaning that we were not able to travel, other than for essential reasons. Luckily many of the East Lothian Countryside Volunteers took up the request to record the butterflies that they saw in their gardens or while they were taking their daily exercise.

The transects took a real hit, though, as it wasn't possible for people to travel in order to undertake these surveys. Only the John Muir Country Park transect was walked all season and two other transects were walked from July until September. There are normally nine transects regularly walked in East Lothian.

But, thanks to everyone's efforts we received 1,858 ad hoc records of butterflies in 2020, a bit down on the average of 2,200, but much better than it could have been. The number of butterflies recorded varies year on year, but has averaged about 13,000 over the last few years. In 2020 we only recorded 5007 butterflies. Undoubtedly the lack of transect records has contributed to this, but some species didn't appear to do very well last year, particularly those that we normally see in good numbers after June.

Because of all of the variability in 2020, it would be wrong to directly compare the figures with previous years, but there were still some very interesting results.

The spring populations of Large Whites and Small Whites, appeared to do well, but the summer generations were smaller than we are used to seeing. This appeared to correspond with the weather conditions during each generation. The ever-reliable Green-veined Whites, though, did well throughout the year.

After the bumper numbers of Painted Ladies we saw in 2019, it seemed odd that we had so few records last year. In 2019 we recorded 5,395 Painted Ladies, but in 2020 we only had 18 records. The number that arrive on our shores depends on how well they have done in North Africa and southern Europe earlier in the year, but it is interesting to see the dramatic difference there can be each year. You would imagine that with so many returning from the UK in the autumn of 2019 that there would have been a good stock to start the 2020 season with. Possibly there was limited food available in North Africa, maybe the weather in southern Europe wasn’t so good and, of course, we would normally expect to see large numbers appearing on our shores in July, when the weather was particularly rainy here.

The big story of 2020 was Holly Blues. For the last few years we have received one, or occasionally two, records of a Holly Blue in East Lothian. These records have usually been from a 5 kilometre stretch of the coast, leaving us to suspect that there was an undiscovered colony in a large garden or other secluded location in the area. Then in 2019 two colonies were discovered in the village of Gullane, right in the middle of that area.

In the spring of 2020 we we received records from that same general area, but also from further along the coast and from 5 miles inland. Then in July and August we had several more records from all these areas and a bit further afield. By the time we received the last record on September 6th, 90 Holly Blues had been recorded in East Lothian. It was an amazing expansion in their range and most of the sightings were from places which are regularly checked for butterflies so they would have definitely been seen in previous years if they had been there.

Two Large Skippers were spotted, one inland and one at the coast. I suspect that there are more of them around, but they tend to whizz from flower to flower and are often difficult to spot.

There was a mass arrival of Red Admirals at the end of June, but numbers were lower than expected later in the year. I guess the weather didn’t help, but I noticed that many of the caterpillars in my garden were attacked by parasitic wasps and perished. I wonder if the same happened in East Lothian?

However, Peacocks and Commas also seemed to do less well later in the year, suggesting that it may have been more to do with the weather.

In contrast, Small Tortoiseshells had a really good year, which is good to see. There is quite a lot of national concern because their numbers have been declining over the last few years. Let’s hope this is the start of a renaissance for the species.

I only received one Green Hairstreak record in 2020. The Covid restrictions meant that it wasn't possible to check most of the site where they have previously been recorded, which are all quite remote.

It was great seeing Wall Browns continuing to do well. It is ten years since they were first recorded in East Lothian and they can now be found almost anywhere in the county.

Meadow Browns and Small Heaths both appeared to do very well in 2020 and it was surprising to receive so many records, as they are not what you would consider to be garden butterflies.

I didn't receive any records of Northern Brown Argus in 2020. I am only aware of four colonies and three of those are not in places that people would have been able to visit during lockdown. There is a colony on a coastal golf course, where I only saw one Northern Brown Argus in 2019. I hope that they are still there and just weren't spotted by people walking past.

We had 23 species of butterflies recorded in 2020 in East Lothian, which is fantastic given the restrictions we were all under.

I am very grateful to everyone who contributed records last year. I hope it won't be too long before we are seeing butterflies again in the spring and I really hope that restrictions will have been lifted enough for us to be able to get out and see them.