Public Access Biodiversity Project Selby
Recorders: Meg Adu Hamdan, Chris Abbott and Nick Hall Walk Time 1 hour
A former barley field converted for biodiversity lies on the south edge of the Escrick glacial moraine on the northern edge of the Humberhead. The sandy silt soil was once part of Skipwith Common. Now an SSSI itrepresents what the Vale of York would have resembled before Intensive agriculture and drainage. It was converted to a bomber base in 1940's and retains the remains of ancient woodland although replanted with douglas fir and infiltrated by Sycamore. The edges bounding the meadow stil have some fine old Oaks and signs of Elm Coppice. The woodmeadow was designed to builds on its heritage as the area is famous for the rare MG5 damp grassland of the Lower Derwent close by. The transect is damp in the south area with reed and sallow regrowth and the route skirts the new meadow and its carefully planned copses of native trees and coppice areas. 40% is seeded as meadow with local provenance meadow mix seed. The route enter Bomber wood, an old dispersal area of the airfield still with its oak trees, then around the boundary of a intensive agriculture field into an improved hay meadow and then on into the PAWS woodland itself and returning along a shady dykeside that bounds the meadow. 1200 invertebrate species have been recorded and more arrive each year along with a new species of butterfly each year. It has benefitted in being close to the old North Seby Mine abondoned for nearly 20 years. Before it was left the coal shale spoil, mostly lime, was bulldozed flat creating a very lareg area of Open Mosaic tended by Hares and wild dear. It has abundant invertebrates including scarce butterfly species such as Dingy Skipper, 6 belted clearwing, Marbled White and Small Heath
The Meadow’s highlight in 2020 was the appearance of the Dark Green Fritillary seen on several occasions but not recorded on the transect. This species was also the highlight of Yorkshire with large numbers recorded and individuals turning up in gardens and appears to going through a migratory phase. In addition the Dingy skipper reappeared on several occasions plus a pair of Marbled Whites were seen by Chris Abbott. The summer downpours in the woodland ment the trees were washed clean of their honeydew, the major food source of some of our canopy dwelling species like the Hairstreaks and they revealed their presence for the first time at low level and occasionally, very unusually, taking nectar. Several Purple Hairstreaks were seen in Bomber wood . The large Wych Elm in the corner of the meadow did not yield any sightings.
Eight species were significantly down even after making some adjustments for the missed weeks. This is likely the effects of 2019 heat on survival of eggs and larvae and the absence of Painted Ladies which were recorded in good numbers in 2019.There was also a significant drop in Red Admirals which are also migratory. Comma and Peacock were down we think due to nectar shortage as this was not the case elsewhere. Small Copper joined Large Skipper with rather low numbers. Common Blue had a disastrous year. Gatekeeper was also down somewhat which could be attributed possibly to 2019 heat or the 2020 spring drought while its caterpillars were feeding up. 6 species showed an increase. Most notable was Small Tortoiseshell numbers were hugely improved returning to much more normal levels after several bad years. Nationally a similar picture was seen with some areas showing large gains but southern England continued with poor figures. This is thought to be much more to do with its parasites. Whites showed similar gains here and elsewhere. It was also better news amongst the Browns (apart from Gatekeeper). Meadow Brown had a super year and made up the numbers lost from the other species plus a lot more and are largely responsible for the larger total of butterflies reported. It achieved 4 weeks of numbers greater than 100 individuals compared to just 2 weeks in 2019. Looking at how individual sections of the transects faired we can see section 3 stands out ( that is the walk along the eastern boundary) and abounded in Browns. The main meadow sections of 1, 2 and 4 were similar but the agricultural field numbers were well down. Bomber wood had sustained nectar and was a solid performer through the season with the richest range of species much like Bishop Wood and numbers were similar in the other sections