Countywide, after a warm winter  April turned  cold, very wet and dull and everything just about stopped and it was near impossible to transect walk all month. By May  there were already  losses  among our spring species being  down a third in numbers.  June brought Arctic winds, a complete reversal of  the Hot June of 2023 when nine  species reached all time highs here and across the UK.  For the  first two weeks of this June  temperatures  were 8’C cooler than  in 2023 around  a frigid  9’C  with  only 5 good days of sun at the end of the month.  The  first three weeks of July had  the same theme of  cool and damp with 5 warm sunny days at the end. Transect walking for many  was very difficult.  The  persistence of the cold and damp over such a long period had a devastating effect with numerically two thirds of our butterflies in the critical later stages of their development; mortality was very high. It was  also one of the longest June  ‘Lulls’  lasting from late May to the beginning of July. When the main flight  season did arrive it  was  slow to build up  and there was no usual peak. Better weather in August helped  save the second generation and very unusually numbers actually went up at the start of September.

  Losers

        For many species it was a triple whammy after  the heat and droughts of the previous 2 years and  last July’s poor flight period this year made it a perfect storm. Overall, annual numbers were down 41% against the average and 45% down on last year.  Half our species were down more than 50% and a quarter down more  than 70%. The Lycaenids, Vannesids and the Fritillaries were amongst the worst affected. Many transect walkers did not see  a single Common Blue, Small Copper, Holly Blue, or Brown Argus until late into their 2nd broods..  Four of our long term declining species Common Blue, Small Heath, Small Skipper and Green-veined White  had  their worst year ever recorded. 

The Winners and less bad losers 

      Northern Brown Argus  had an exceptional year up near 50%  Other species bucking  the trend were Brimstone and Marbled White. The  damp  loving Ringlet on many limestone/dry sites  were up a half  while on most wet sites they fell by a half.  However if it wasn’t for Ringlet holding up the overall numerical losses, this year would have been significantly worse. It often happens when Meadow Brown has a very poor year, like this one, Ringlet does proportionally better, and vice versa in a warm year. 

It has all happened before… many times.    

It was our worst year since 2016 but nearly as bad as 2009  when numbers  were  down 50%.  2024 comes after a run of 6 relatively good years since 2018  along with  rapidly rising temperatures including 2 of our hottest summers which were followed by two of our best butterfly years in 2019 and 2023. It is  likely 2024 was a blip

Lea Green did well to show and increase of 4% in numbers as so many calcareous grasslands suffered badly anything up 25% down.  The pattern of increasing numbers continues and builds on a cracking year last year!  Northern Brown Argus  was down 30% which was about typical this year and 70% down on Dark -green Frillary was pretty universal too.  In fact most trends here follow the county ones with huge increases in Red Admiral, Brimstone and Meadow Browns balanced out by equally big drops in Ringlet and Small Heath which are drought sensitive.  Great to see  Green Hairstreak have its best year in over 20!  and Wall have a superb year its highest on record here and double teh previous best, last year!  The county is seeing a remarkable resurgence of thsi species across all landscapes.  Speckled Wood exploded and Scotch Argus had another great year.  Brimstones  arrival just 2 years ago and already numbers are excellant. A remarkable site seeing remarkable positive changes.  If last year had not been quiet so dry thsi year coudl easily have beaten 2013-14 high point for this site.

The best year since the 2013-14 big peak  and numbers have nearly doubled in twenty years  with teh site becoming more calacareous grassland. Northern Brown Argus has nearly doubled along with other grassland species with Meadow Brown near trebling. Brimstone was seen for teh first time this year and Orange tip  looks like it is trying hard with a big jump in numbers this year . Small Skipper  doubled over last year and had a good summer  and large skipper seemed to suffer in teh drought as it did back in  2018-19. Northern brown argus dropped back from its average after an exceptional year last year and follows teh pattern elsewhere of suffering from drought.  we should expect to drop even lower next year as a consequence, Although Small Tortoieseshel held its own while it has been near universally down elsewher Peacock halved in line with teh county, again suffering under the drought. Dark green fritillary has dropped back in numbers in teh last 10 years and was quite low this year at about a fifth of the peak which reflects teh changing habitat.

last year speckled wood boomed but fell back thsi summer under less good moist conditions. Its great to see teh wal lback these last two years after a gap of nearly 10 years. Scotch Argus has been seen spasmodicallly since 2013  but becake resident in 2019  with this year alos being quite good.  The Meadow Brown and Ringlet both boomed  doubling or treblling on last years numbers enjoying the warm June weather and reaching numbers not seen since 2013-14  while Small heath, as it did almost universally, fell back slightly.

2021 sees a improvement over 2020 but not quiet as good as 2019 an exceptional year.  The biggest improvemnt have been in Northern Brown Argus and Scotch Argus having bumper years . Small Heath along with Meadow Browns were up  and it was great to see the Wall returning browns

A pretty good year with the scarcer species holding up well with only  Ringlet  showing a decrease after the long hot summer of 2019 and drought of spring 2020 . Common Blue and particularly Small Tortoiseshell had a very good year.  NB alot of the data is based on estimates as walk frequency was low.