The Suffolk Argus northern Scotland and East Anglia were slightly drier than average for the year. The provisional UK sunshine total for 2019 was 1455 hours, which is 106% of the 1981-2010 average. Eastern areas fared best relative to average, getting within the top ten sunniest years for some areas. February was the second sunniest on record for the UK. (www.metoffice.gov.uk)
Brimstone enjoyed a “statistically significant positive 10-year UK trend, of 108%”. The long hot summer of 2019 seemed to pay some dividends with many grass loving butterflies enjoying a good year. The three golden skipper species (Essex, Small and Large) all held their own and Meadow Brown and Ringlet showed small increases on 2018. However, despite having a great year in 2018, summer woodland fliers seemed to struggle and both Purple Hairstreak and White-letter Hairstreak saw numbers fall along with those of White Admiral. Both Purple Emperor and Silver- washed Fritillary remained at a similar level to 2018.
3. Residents, Winners & Losers (See Annex A- Scarcity for species seen in Suffolk in 2019). For me, 2019 felt like a rather average butterfly year but I was very interested to read the annual report from the UKBMS which identified 2019 as the 8th best year out of the UKBMS recording series covering 44 years. It was also the best year in this series since 1997, with just over half of species (53%) showing a higher population index compared to 2018.
Sadly, 2019 was not a great year for some species with Common Blue, Silver-studded Blue and Grayling (see below) all struggling in Suffolk. Disappointingly, these three species also struggled at a national level 4. Early & Late records. (See Annex B- Suffolk Butterfly Species Earliest and Latest dates up to end 2019).
The year promised a Painted Lady invasion and although it was a very good year for this species it wasn’t a classic year and certainly fell short of what we experienced in 2009 (see below 5. Migrants and Rarities). That said, Painted Lady was the fifth most abundant butterfly in Suffolk for the year behind Peacock (4th), Large White (3rd), Red Admiral (2nd) and Small White (1st).
A review of Annex B provides for first and last records reported for each species seen in the year. This information sits alongside the Earliest and Latest dates recorded for each species as county records. Only one new earliest date was achieved in 2019 and this related to a White-letter Hairstreak being seen on 18th May (Sandy Drove, Icknield Way), beating the previous earliest date for this species of 30th May 2015. A Swallowtail sighting on 3rd September became Suffolk’s latest.
Garden favourites Peacock and Small Tortoiseshell both enjoyed year increases from 2018. Of note, numbers of these species recorded from Butterfly Conservation’s Big Butterfly Count increased considerably with Small Tortoiseshell up 167% and Peacock up 235% on 2018 results. Both species also recorded their highest number of records since the Count commenced in its current form in 2010. In Suffolk, to me Small Tortoiseshell remained scarce and disappeared early to hibernation. An interesting paper is available to read on this behaviour, written by Malcolm Hull from the Herts & Middx BC Branch. See link https://hertsmiddx-butterflies. org.uk/SmallTortoiseshells.pdf
Of note, last year’s table contained an error for the earliest date for Orange-tip. This was reported as 16/02/2015 whereas it should have remained at 9th March 2014. That said, Orange-tip was seen later in 2019 with a new latest county date recorded of 8th August and suggests a partial 2nd generation. 5. Migrants and Rarities. Overall, 2019 was generally poor for migrants in respect of the variety and extreme rarity of species. However, migration was to some extent significant in respect of Painted Lady, Red Admiral and Small White.
The warm weather experienced early in the year certainly helped a number of spring species with Brimstone doing particularly well in Suffolk. Nationally, according to the UKBMS report 6
