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

Upper Dunsforth was somewhat down on the county results but similar to other damp  lowland sites. It is significantly worse than the previous worst year in 2016  and  sadly zero Small Tortoiseshells were seen.

Upper Dunsforth saw  a similar increase in Overall numbers to teh county average.  It also follows pretty closely the county trends across the species. The big losers were those sensitive to drought namely Ringlet and Green Viened white. On teh other hand after last year heat numbers really built up for Meadow Brown, Gatekeeper, Holly Blue , Speckled Wood , Comma and of course Red Admiral all of which  had their best year ever here and across the county.  Wall Brown wasnt seen this year but be assured it is having a good time and still spreading in the Vale of York although due to drought numbers were down.  Its lots of respects a spectacular year but not universally. 

A  poor year in the drought with  many species suffering in particular big falls in the Vanessids but also the Whites,

 Peacock and Small Tortoiseshell really suffered  and none were seen after early July. 

Comma in common with the county trend boomed on the summer (hutchinsoni)  generation 

Although Speckled Wood  and Ringlets suffered  the rest of the browns in a large part made up for the other losses particularly Gatekeeper which tripled. 

Overall  -12% down was not so bad! 

Its great to see the Wall back and trying to establish of which can be seen in other localitiees too

In the long term numbers are decreasing slowly  of the more common grassland species which does suggest some deteriation 

A poor year  27% down on teh average  Almost all species  down on the average by 30-50% . Large Skipper was absent for the first year. 

Biggest loosers werepeacock and speckled wood. Winners were Ringlet up slightly and gatekeepr boomed as it didi in almost all locations . 

The Tortoishell boom has fizzled out! but continues apace eleswhere

Great to see the Wall back

A close to average year although lower than 2019 with its  invasion of Painted Ladies. There was some reduction in Smal Skipper and Ringlet but the wet site seems to have come through the drought of spring 2020 pretty well. As with many other areas there was a considerable booom in Small Tortoiseshell.

Some adjustement were made for the first weeks missed during lockdown:   Brimstone +4. GVW +5,  Orange tip  +52, Peacock +15,