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

Flatts Lane is following a fairly steady decline, halving over a decade, and this year follows that trend with only a very few species following the county trend and booming mostly Meadow Brown.  One of biggest declines is in Small Skipper that has dropped from hundreds to low teens and is of concern that teh habitat has changed fundamentally.  Here Wall Brown follows the county trend of Increasing and although almost everywhere thsi year it decreased here it increased !  Great to see the Grayling back in numbers not seen for nearly ten years. The Vanessids have been very poor for 2 years now following the county wide crash but hopefully after this wetter summer we might see a resurgence next year with usually Peacock leading the way. 

A good year with a big jump of 22% in numbers overall  but with some big winners and losers as in many  transects this year. The Skippers and Whites other than the Orange Tip were   losers and only the Comma amongst the Vanessids showed a slight increase compared to big loses for both Tortoiseshell and Peacock, as on all transects.  However, the Speckled Wood showed a strong increase which was nearly universal across Yorkshire which recouped most of the losses so far. Wall also had a good year with a 8 fold increase over last year  and double the average.  Apart from the Small Heath,  which had a universal poor year, the real winners which boosted the years total were the browns in particular Ringlet

An average year and only 3% down from the 5 year average  with 2018 and 10 being exceptionally good it was isgnificantly better than 2020. The trend with the golden skipers continuews to be going down with lareg skipper hanging on The whites had a good year  with orange Tip in particular having a very good year. In addition Small Coppter and common blue were both up . The  Small Tortoiseshell boom continues. but teh othe Vannessids did poorly. The damp loving  Speckled Woods and Ringlets both had good years and compensated for many of teh losses in teh other species.   The other browns did rather poorly including surprising Small Heath

 2020 Showed a small decrease with a dull wet summer.  However,  the  White's,  Small Tortoiseshels and Small Copper showed  increases . A drop in the grassland species  of Meadow  Browns and Small Skipper and the disappearance of Large skipper could be due to the drought conditions of spring 2020.   The reduction of  S4 grassland species is very noticeable  as the habitat becomes less favourable. Wall Brown is maintaining its numbers while Small Heath shows a slow increase