Wheldrake Ings YWT
Lower derwent Valley
York
Site Description
Recorders: Sarah Robinson , Emily Clarke, Fiona Bruce, Terry Ram, Richard Leathley Distance: 2689m Walk Time Approx: 1hour 30mins
Part of the lower Derwent valley reserve and its treasured MG5 grassland the site is often flooded in winter.
In summer its meadows are awash with Great burnet, Meadowsweet, and Meadow vetchling.
Sections:
S1, relatively low counts of common species
S2 generally has one of the highest counts and along with S4 tends to be the favourite area for Orange Tip and Small White S2-S3 is also teh area favoured by occasional Dingy Skipper, Common Blue, Gatekeeper and Wall, Small Copper and Small Heath
S3 along with S4 tend to be the favoured area for the Vanessids
S4 in more shady areas with Speckled Wood appearing and is also favoured by Meadow Brown and Ringlet
S5 Meadow Brown can be most numerous
S7 has a low count
Results 2024: Insufficient data
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
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%.
At Wheldrake Ings overall numbers were down on the average largely due to the very poor performance of Peacock and Small Tortoiseshells which are often the two most abundant species on this site. Even so they were marginally up on last year and the first signs of recovery after big fall in 2022. Across the other species there is a good deal in common with county trends with Ringlet dropping back on last year universally. The big winners were Comma, Red Admiral, Meadow Brown, Gatekeeper Speckled Wood and Brimstone all of which had record breaking numbers across the county. It could have so easily been a record breaking year here only held back by the vanessids!
Results 2022:
A big increase on the last two years but still quite a way behind the good summers of 2018/19 which stand out at a modern day highpoint and 11% behind teh 5 year average there were lost of ups and down in common with most sites as a consuence of the heat and drought. There is a surprising big difference between years at this site which seems to be not unusual on floodplain habitats .. every species either does extrememly well or extrememly poorly . This is certainly true amongst the whites however this year as with most localities both the Brimstone and Orange Tip are up average . Small Skipper counts are always very low which is a surprise for such a grassalnd site but the majority of the site is cut for hay. Dingy Skipper is likely visiting occasionally from surrounding sites like the North Selby mine close by. Holly Blue returned after a absence of two years but not quite back to average and this species has been seen returning to many sites in the spring generation. Small Tortoiseshell was well down on the recent years boom but no nearly as much as other sites with good numbers in June and then zero in August and the second generation failed completely. Similarly with peacock just low numbers seen in July and then nothing and was responsible for much of the losses for teh year. In contrast Comma boomed almost everwhere and a very strong showing here but then again nothing later. Similar to other sites speckled wood had an excellent year particularly in September. Gatekeeper also thrived as with other sites and was almsot universally up . Meadow brown was a tad down on average buit stil way up on teh previous two years nearly doubling as did Ringlet.
Results 2021:
This riverside route is subject to much annual variations of water levels but also of butterfly species with ocassional explosions of some in good years like 2017-2019 foloowed by crashs.
There were huge peaks of Peacocks and Meadow Browns in 2019; then Whites in 2018 so the regular floods do seem to be the key factor. For example Meadow Brown 448 in 2019 and just 15 in 2020 but there was extensive floods in February 2020 and you can guess the larvae were drowned
Following the riverbank and does mean there is often good quantities food plants for Orange tip and Small White both of which are occasionally in very high numbers. Comparison with the 5 year shows 2021 in a bad light of almost eveything down but there are exceptions which fit very well with Yorkshire trends. Small Tortoiseshell continues to boom and Small Heath is showing a strong upwards trend. Biggest loosers are Comma and Peacock. Also missing in 2021 are the occasional visitors/breeders of Small Skipper, Dingy Skipper, Holy Blue, Brown Argus, Painted Lady, Common Blue, Wall and Gatekeeper.