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

Barlow results pretty much reflect the county picture  with Red Admiral setting a new site record. Comma and  Gatekeeper alos did very  for teh second year. All the whites did poorly apart from Brimstone than boomed universally, Overall numbers were only down a tad so not bad for a brownfield site which has both wet and dry areas.  Biggest losers were Orange Tip and Common Blue while Cransebill Brown Argus, as elsewhere, had a great year. 

A rather disappointing year 5% down on th 5 year average with only Brimstone and Green Viened white up  and the rest of the whites down although this is following county trend . However Dingy Skipper made a spectacular return and has been doing well in a few locations where Birds foot trefoil flourishs, All the blues were  down but  Holy Blue stands out as on the majority of sites are way up.  Common Blue in particular  had another really bad year and  the trend since since 2019 has been unusually rapidly downwards  which could indicate site conditions.  All the Vanessids were  well down and, unusually, so was Comma but less so than the others down 15%.  In contrast Small Torts  were only an eighth of their 2021 boom count.  Speckled woods who were almost universally up barely held  ground. As with county trends all the browns did well particularly the Gatekeeper and Meadow Brown having record years.  Only Small Heath fell back as on most sites.  The real reason for the fall in numbers  overall is being woodlands  contains a large population of Vannessids which did particularly badly as they  did not produce a second generation, partly due to the heat but also due to poor nettle quality and higher than normal parasite  (Sturmia Tachinid Fly) It was simply a perfect storm! 

2021 was a very poor year for almost all species. Particularly bad were Large White, Comma and Speckled Wood. In line with other transects Small Tortoiseshell had a boom year and Gatekeeper and Meadow Brown had good years.  Unlike most other transects where Small Heath boomed here it had a poor year. 

Numbers are a little down after the previous two excellant years.  The drought of early spring 2020 may be partly responsible for some of the losses.  In particular a dramatic drop in Ringlet which favours damper longer grass or shade along with Green veined white which was also well down. Gatekeeper was similarly hit along with Small Copper. The excpetional was Brown Argus  and Small tortoisesheel had a bumper year as it did on many of our transects.