Embsay Reservoir 

Countywide, a bumper year that could not have been more opposite to 2024. Butterflies were seen, and flight conditions achieved, almost every day from March through to August. Butterflies boomed in the warmest  and sunniest Spring and Summer on record. Sometimes they were seen in clouds, mostly Large and Green Veined whites, either as migrants coming in from the sea along our east coast or in sheltered flowery places where they accumulated in huge numbers. Other species were behaving similarly with clouds of Speckled Wood and even an observation of a cloud of Purple Hairstreak above a tree. Yes, butterflies were swarming, a prelude and postlude to migration and dispersal and this year’s records clearly show this; they were on the move! So,it is no coincidence that it was the best year this century for Clouded Yellow. It wasn't just the sheer numbers, almost every species was absurdly early, averaging two weeks early! By the end of April abundance was already up 50%  with record counts of Peacock, Speckled Wood and Brimstone, with some transects recording  over 100 insects each week; remarkable as these were summer time numbers but we were still in April! An amazing 22 species were on the wing  by the end of that month, which is double twenty years ago and 30 species by the end of May with both Marble White and Silver-washed Fritillary had started to emerge. We had never seen a year like this! 

 It was also the driest year in a century. By early June plant growth slowed, lawns rarely needed a cut, soils cracked, crops wilted, verges went brown and no hay crops as grasslands were so short and sparse. There were consequences and the boom was certainly not universal with many doing exceptionally well while others were well below par. On thin soils the grass feeding ‘Browns’ which make up the majority of our summer species fared particularly poorly and in fact at Wharram Quarry, with almost no soil, numbers were lower than in 2024 as they were on Inglebrough’s Limestone pavements!  This was contrasted with the damp, deep moist soils in the river valleys where those  same brown species were booming particularly in part shade of our woodlands and hedgerows. 50% of our sites were up more than 40% and more than double last year’s total. The Blues and Small Copper bounced back from last year's disaster and boomed on the warm thin sparse swards. Small Copper earned its place as ‘species of the year’ by having not only its best year on record with an enormous third brood; 33 times higher than last year, which happened to be a record low. The exceptions were the Small Heath only managed to struggle back to average while the Small Tortoiseshell after a great start, and quite a good first generation the heat and drought caused them to go straight into hibernation and few were seen after mid June except in cooler/damper locations and is forced to higher altitudes to escape.Overall the year was up 30% against the 5 year average and has beat every year since the millennium! For 20 of our species this was either their best or second best year on record. Large White, Brown Argus,Dingy Skipper and Speckled Wood had their best year.