Bishop Wood FE


Owned and managed by Forestry commission

Site details

Recorders: Nick Hall and Mary Ratcliffe Length 4260m Walk time : 1 hour 15 mins

Bishop Wood just north of Selby has always been an important ancient woodland site. Named after Cardinal Wolsey the archbishop’s palace stood at nearby Cawood At just under 1000 acres it is easy to lose your whereabouts when walking. Owned by the Forestry Enterprise and operated commercially it is the largest wooded area in the Humberhead Levels. There are still extensive tracts of Oak, Poplar, Ash and Sycamore but commercial fir trees blocks dominate the northern half. The forest is being quite intensively managed to return to a original state with thinning around established oaks, ride widening, and periodic areas cleared for Birch regrowth to encourage the red list Argent and Sable moth. This year follows a very busy thinning year last year with clear felling conifer copses and replanting with native trees mostly Oak in about 12 locations on the north side east half. This is a first for the forest and has created large open areas in addition to the thinning and ride widening sees strong Violet growth.

The wood is a favourite place for our woodland species with high numbers of Comma, Peacock and Brimstones but also many other common species. There are a small number of Wych elms and White Letter Hairstreak is seen and Purple Hairstreak can be locally abundant. Brown Argus is found on its alternative host plant Dove’s Foot Cranesbill. There is a colony of Dingy Skipper along the railway which cuts the western edge where Birds Foot trefoil (BFT) abounds. This railway service road on the east side of the track is a particularly good area to observe many species of butterfly and is a mass of primroses in March. The west side of the track is also a mass of Primrose, BFT, Agrimony and Violets but is rarely visited by people. The transect covers a network of the wider rides whose junctions on the northern half (S5) where Birch regrowth is prolific is particularly good for seeing Argent and Sable moths. About a third of the transect includes denser overgrown rides lined by ancient sallow coppice and grey willow and their hybrids where Honeysuckle forms the lower canopy and the floor is liberally covered by Dog's Mercury, Bluebell, Wood Anemone, brambles, and patches of Dog Violets. Highlight species include the majestic Silver Washed Fritillary that arrived in 2017 and is happily settled with form valezina seen for the first time in 2020.


S1 is mixed coniferous blocks and mature deciduous being thinned to encourage Oaks and where Purple hairstreak is seen in sunny pockets and Speckled Wood and GV White. There is a cluster of Elm where it meets the railway line road. S2 is along the railway side and abounds with herbs and is a special favourite with Brimstones Peacocks, and Silver Washed fritillaries. S3 we make our way back into to shady rides back to the main road where we started. Crossing the road into S4 a well lite ride has more species with Comma a nd Ringlets. S5 starts at a road junction with sallow and birch regrowth and this open ride with good nectar is often the favourite place to see peacock, SWF and Comma. particularly at its end near the logpile where Argent and Sable is commonly spotted. S6 is a wide shady ride with and after a couple of clearings you take the Path back towards the south dep in the wood and very shady to Pringles Bridge which has good violet areas and is anothe rfavouruite of our woodland species. S8 return via Park nook road which is wide bracken filled ride often used by Brimstone, Comma and Silver Washed fritillary

2022 Results: Gatekeeper and Speckled Wood boom while Small Tortoiseshell and Peacock bust

Overall 7% down on the 5 year average was mostly down to the lost generation of Tortoiseshells and Peacocks and to some extent Ringlet although these big losses were compensated in large part by the boom in Speckled Woods. The golden Skippers were both down as elsewhere. Birds-foot trefoil is growing profusely in the chalk roads along the railway-side road this year after its regualr srape so both Dingy Skippers and Commonm Blue had their best year but does not reflect a trend rather a highly managed habitat of the forest. Brimstone was up mostly with good numbers overwintering from the boom the year before. Large White was down, like elsewhere, and Small White up but these two species do show alot of variation site to site and year to year. Green-viened White was up while on most sites were down possibly refelecting this is a wet stronghold of this species. The damp loving Orange Tip was also up. As everywhere else the Vanessids were down especially Peacock even though all species overwintered well, failed to have a summer generation. As everywhere else Comma had a good year with a strong hutchinsonii generation, although they disappeared into hibernation very quickly in the second generation. Bishop Wood is well known for being teh heartland of the counties Silver-washed Fritillary population was well down on last year. However, considering at least half their rides had cleared during extensive thinning operation by Forestry England which greatly reduced the violet population although we can expect this to bounce back strongly next year proving how dynamic forest habitat under management, with a strong human influence on its proceedings . As with the Green-viened White Speckled Wood had a bumper second brood revelling in the heat. Gatekeeper as elsewhere also boomed but Meadow Brown was down as was Ringlet . Argent and Sable was recoded on two weeks with 3 individuals seen which is about normal but not as good as 2019.

Transect reports 2020

2021 Another good year despite the poor start with Brimstone and Silver-washed Fritillary booming

Although total numbers were down against 2020 over the three year average it was up near 10% which is a surprise considering how bad the spring weather was which then created a significant delay in the main season. The spring saw very high emergence from hibernation of Brimstone although the summer brood numbers were a bit down numbers were still 4 times higher. Orange Tip was also at good numbers almost double previous years. Amongst the white Large and Green-veined White were average , but Small White saw a noticeable rise almost exclusively in the second generation. Small Skipper saw quite a drop as did Large Skipper to a lesser extent. The hairstreaks were alos somewhat down but this might well be due to other factors.

Red Admiral was down again and Small Tortoiseshell boom continues with a strong 2nd and third brood. peacock emerged from hibernation well and then suffered a disaster with a peak of less than 20% of 2020 good year. Comma also had a bit of a disaster with numbers halved. They were compensated for in numbers by Silver- washed Fritillary who seemed to boom after all the forestry thinning operations and ride widening these last 18 months. Their number nearly quadrupled. and was the commonest specie sin the forest for 5 weeks on the trot. Speckled Wood also benefited a little. The other Browns also faired well with meadow browns increasing significantly. You can speculate that the lush grass growth from ample rainfall this year has benefited quite a number of species and has compensated for the atrocious spring weather and delayed emergence. Gatekeeper bucked the trend of elsewhere and was down but boomed on the majority of transects

Argent and Sable moth showed again after a poorer year in 2020 unless it was missed during lockdown but not quite a good as 2019 An extensive survey was carried out by volunteers and concluded that the main concentration of the population is centred on S5 down to the log pile but also to the east by the side of the dike proved a hotspot and Hammersike either side of the log-pile and the path west from the main car park


Bishop Wood saw a remarkable 42% increase in overall numbers of all species! The highlight was a good many White-letter Hairstreaks were seen for the first time. Silver washed Fritillary had a early start and a late finish although numbers per week were probably 20-30% down. Purple Hairstreak was seen in good numbers along with more Dingy Skipper along the railway side (S2) However things were much influenced by a large new area of nectar plants including Primrose, Dog Violet, Birds Foot Trefoil and Agrimony followed by Knapweed, Teasel, Fleabane, Marsh Thistle, Meadowsweet, Marsh Valerian and Angelica along the railway side (S2) which has grown after being cleared in late 2018 ( S2). This abounded with life throughout the season and saw huge numbers of Peacocks (400 peak) in the last 2 weeks of July along with the Whites and other species. The summer downpours ment the trees were washed clean of their honeydew, the major food source of some of our canopy dwelling species like the Hairstreaks revealed their presence for the first time at low level and occasionally, very unusually, taking nectar. In addition the foresters moved in with heavy plant and the wider chalk roads were scrapped and reinforced with fresh chalk, which meant most of the nectar plants on the ride sides were lost. This greatly reduced butterfly numbers of some species while others simply moved to the railway side. This is very much reflected in the sections counts