Roach Hills
including Shuttocks Woods and surroundings
YWT reserve
Details
Recorders: Rachel Inhestor Altitude 90m Length 1918m time : 1hour
Lying at the top of the Magnesian Limestone ridge this transect includes SSSI site Roach Lime Hills and is partly unimproved calcareous grassland but there is encroaching scrub. Transect also cuts through broadleaved woodland and includes a public footpath which passes through farmland crops.
Sections
S1 Unimproved calcareous grassland and a little scrub
S2 an Arable Field
S3 edge of an arablel field with a hedgeline
S4 fottpath with calcareous grassland beyond the hedge linings also bordering Woodland
S5Calcareous grassland of teh SSI managed in sections by sheep
S6 Arable
S7 + S8 Wooded area on the edge of housing estate
S9 Scrubby area with patches of calcareous grassland.
Results 2024
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
Roach Hills was a tad better than the county average which is in line with dry sites this year. As with other calcareous sites Marbled White was up along with Ringlet as the habitat recovers from two years of drought. Small tortoiseshell suffered badly but was still seen here unlike many sites.
Results 2023
County wide 2023 results reflect the 2022 Heat and drought with Small Tortoiseshell and Peacock nearly halved for the second year against their 5 year average. Red Admiral arrived in force in July and took advantage of soft nettle growth of the rains and had their best year ever. Drought sensitive species on thin soils were badly hit, particularly Dark -green Fritillary and Northern Brown Argus but also Ringlet, Green-viened White and Small Heath. Less drought affected species along with the hottest June on record built even more on gains last year leading to Comma, Brimstone, Holly Blue and most Browns having a fantastic year reaching all time highs. A increase of 9% overall was mostly due to sheer numbers of Meadow Browns and Gatekeepers ment 2023 nearly pipped 2014 as best year in modern times. Most noticeable was the large differeces between moisiture retaining mineral soils of the valleys and thin, dry limestone or sandy soils. A large number of damp grassland, hedgerow and woodland dominated sites benefitted hugely with 3 sites seeing more than 50% increase . A smaller number of thin, chalky, sandy or craggy sites did badly some down up to 25%.
Roach Hills did well as part calcareous grasslands which were well down elsewhere but hedges and woodlands did well so only down 3%
It follows the county trends mostly with big increases in meadow Brown, Marbled White and Gatekeeper. Ringlet was universaly down as a drought sensitive species . Wonderful to see Wall return where in many places it suffered loses it also managed to increase its range! Its presence makes this transect even more intersting.