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

Green Hammerton had a pretty good  up 6% and close to the county average but still a tad down on last year. Species trends follow the county trends fairly closely with the big winners being Gatekeeper and Meadow Brown and big losers Peacock and Small Tortoiseshell. As eleswhere there were record numbers of Brimstone, Holly Blue and Comma. Speclkled wood saw a bit of rise although elsewhere it broke records to its best year ever.. Red Admiral also had its best year since the 1990's and showed strongly on all transects apart from those at the highest altitudes. Great to see Wall clinging on even in this bad year for this species. The site trend is still for steady strong increase in total numbers. 

A massive increase in numbers on this developing site with almost all species increasing.  The big winners were Gatekeeper and Speckled Wood which universally boomed across Yorkshire . An increase in Gatekeeper of 10 fold  in 3 years is remarkable. Common Blue is also benefitting from the improving habitat and Wall Brown has been returned as has Large Skipper. Holly Blue exploded as it has done universally. Bad news is short but Peacock had a very poor year with only a very small summer generation. Unusually Small Tortoiseshell  has nearly held its ground against last years boom and is at very high numbers  For most of lowland Yorkshire Tortoiseshells crashed and some sites saw none after June which was the same at this site with the second generation basically 'cancelled' as the first generation hibernated immediatly  in the heat.  Meadow Brown was well down on the last 2 years but held onto average

As with many transect this year sees a big rise in Gatekeeper numbers as the species recovers from  drought in early 2020 but all the browns have benefited  to make for the best year so far.  As elsewhere the Vanessids have had a bad year particularly Comma apart from the Small Tortoiseshell whose boom these last two years continues.  The cabbage whites also had a pretty good year. Unfotunately Wall has not returned.  Holy Blue was absent and had a disasterous oear as it did elesewhere. Small Skipper has maintained it  numbers after a rapid rise in the last two years  but Large Skipper remains absent

2020 saw small skipper creeping in in numbers into Helenfield and the near disappearence of Large Skipper. Small White  had a good year and Orange Tip were in good numbers again along the lanes and on the woodland edge. Small Copper had a good 2nd brood.  Tortoiseshell and Peacock saw a good rise in the maturing woodland and the Browns maintained rising numbers  The migrant Painted Lady and Red Admiral had a poor year