Ellerburn
Bank YWT
Thorton le Dale
Site Details
Recorders: Ian Popely, Graham Oliver and Paul Cogan Distance : 925m Altitude: 145m Walk Time: 45mins
Ellerburn Bank is a 3 ha. grassland site sloping south-east on oolitic limestone on the southern edge of the North York Moors near Pickering. Despite its modest size, it is one of the most extensive areas of unimproved limestone grassland remaining in the North York Moors . It was notified as a SSSI in 1983 and has been managed as a nature reserve by the Yorkshire Wildlife Trust (YWT) since 1966, having been informally managed for nature conservation perhaps for the previous decade. The flora and fauna of the site is exceptional for the region, with over 150 species of plant recorded including large displays of Cowslip in spring, orchids in early summer and Gentians in late summer . Flowering plants of regional note include Dropwort, Woolly Thistle, Saw-wort, Fly Orchid Ophrys and Greater Butterfly Orchid. The site is noted for its extensive Lepidoptera fauna , including butterflies of regional note such as Dark Green Fritillary and Dingy Skipper Erynnis tages, and the site also supports a population of Glow-worm Lampyris noctiluca. Management of the reserve currently consists of low-intensity winter grazing by Hebridean sheep and rotational scrub clearance.
Sections
The upper, northwestern margin borders an agricultural field and consists of a Bronze Age earthwork (a double ditch and bank) partially covered with Hawthor and Blackthorn scrub, S4 (record bank side only ) and S5 whilst the lower, south-eastern side bordered by forestry S7, consists of a patchwork of taller grass and Gorse following the lowest path. S1 follows the north east boundary dry stone wall and is favoured by Wall brown and Dingy skippers and lizards. The southern edge is sheltered and changes to isolated gorse bushes S3 returns to teh entrance and S4 follows the ditch southwards.
2024 Results
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
Ellerburn Bank was down rather more that the county average. Losses were across the board although teh site speciality brown Argus was down near 90%. Some vannesid did wel lwitH Comma doing well and Peacock which prorportionally was not bad in fact numbers were double last year as they continue to recover in common to most sites. In contrast not a single Tortoiseshell was seen. In addition no Dingy skipper were seen. Losses among the damp loving browns were high particularly Small heath, while dry loving Meadow Brown did better which is a legacy of the two previous drought years. Speckled wood also increased and Silver washed was seen again for the second year.
2023 Results
County wide 2023 results reflect the 2022 and 2023 spring 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 mositure 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%.
Ellerburn Banks calcareous grasslands are succeptible to drought and although drought resistant species prospered those there were not significantly decreased . Overall numbers were down 11% whiel county waise were up 9% but it was a mixed picture. The big winners were Marbled White and Meadow brown that have thrived in last years hot summer and this year very hot June. Speckled wood did surprisingly well as they did across the whoel of Yorkshire in likely their best year ever along with Brimstone and Red Admiral. Drought sensitive Ringlet and Small Heath suffered badly but Common Blue was even worst . Wall and Dark-green Fritillary suffered badlyeverywhere . The vanessids all did badly ( apart from Comma) and only in the dales did we see the beginning of recovery of these species.
2022 Results
Small Skipper is having a bad time in Yorkshire but here it it significantly worse possibly due to the dry nature of the site and it follows the county pattern of the 3rd year of decrease. Large skipper although better than last year is also on a down. Dingy skipper follows the county pattern of being a bit down on the good years, Brimstone again follows county trends in being up . The whites dont follow the county trend being well up on this site while down in the county. However Orange Tip was well up as in the county trends . Small Copper showed a loss as in the majority of sites. Brown Argus was down on this upland limestone site as it was on other rockrose sites while the migratory form was well up on its alternative foodplant cransebill down in the lowlands. Common Blue was also down but held its ground on other sites. All the vanessids were down apart from Comma which was well up and follows trends across the county with neither Small Torts or Peacock producing a second generation and later having a very grim time, Dark Green Frits were also down as in other parts of the county. Speckled Wood boomed as they did elsewhere particularly in later broods. Meadow Brown boomed and Ringlet was well up more so here than in other sites . In common with the county Small Heath was down along with Marbled White,
2021 Results
Overall numbers were down somewhat compares to the boom years of 2018-19. The large skipper did not reappear after a rapid fall last year and even teh Dingy skipper was down possibly the effects of last years drought spring. Green viened white had a good year as tehy tend to enjoy a wet summer. Small Copper was also well up but Brown Argus had its best year since 2018 . common blue in contratst continued a trend of decreasing . The vannessids in common with most transects had a bad year particularly Comma. Speckled woods and most of the browns were down apart from Small Heath that had a boom similar to other transects and Ringlet had its best year for some years. Unfortunately Wall was not seen thsi year after better numbers last year but we know they tend to hate wet summers like 2020-2021.
Things in general still in good shape.
Results 2020
After two cracking good years numbers have fallen back only marginally and held up well during teh poor summer of 2020 but it may well have benefitted from the long hot dry spring. Skippers were down along with Green viened white and Speckled wood which could be related to the spring drought but its great to see the Wall back in good numbers and Small Tortoiseshell after years in teh doldrums have a boom year along with Small copper and to a degree Dark Green Fritillary. A good deal of estimating had to be done for the spring species so its difficult to comment . Overall things look in good shape.