The Duke of Burgundy was found historically in coppiced woodland where it used the primrose exposed by coppicing for egg-laying. Over a period of years the coppiced area become overgrown and the butterfly will move using forest rides to newly cleared coppice areas.
Coppicing has declined dramatically from the twentieth century onwards but at the same time there were changes in the management of chalk and limestone grasslands which had been historically used for sheep and cattle grazing. Many pastures were ploughed and used instead for the growing of cereals but ploughing of steep hillsides is not possible and many hillsides were left ungrazed as scrubby grassland with cowslips. This provided an alternative habitat for the Duke of Burgundy during the twentieth century. There were estimated to be about 200 remaining Duke of Burgundy colonies in England at the end of the century with only about twenty remaining ‘woodland colonies’.
The national distribution of the Duke of Burgundy is shown on the map above. It’s remaining strongholds are on the chalk downlands of southern England but it is also found in two areas in northern England-on the limestones of Morecambe Bay in Cumbria and on the southern edge of the North York Moors. Unfortunately ungrazed chalk and limestone grasslands are subject to rapid succession to scrub and trees in particular hawthorn, hazel, and ash which will lead to the loss of colonies. ‘Countryside stewardship’ schemes designed to halt this process encouraged the removal of scrub and intensive grazing regimes often involving the sheep which resulted in a habitat which is unsuitable for the butterfly due to the loss of shelter and sward heights which were too low.
The Duke of Burgundy began to decline rapidly throughout its range in the last part of the twentieth century suffering a 46% decline between 1995-1999 and 2004-2009 and became one of the five highest priority species for Butterfly Conservation. There was a major Butterfly Conservation project in Southern England which began in 2011 called ‘Dukes on the Edge’ which sought to address the decline in the Duke of Burgundy. This developed innovative schemes to halt the decline on the southern chalk downland in particular the changing of stewardship schemes to replace sheep with controlled winter grazing by cattle coupled with controlled scrub management. These approaches have been particularly effective in Sussex where the butterfly has literally been brought back from extinction. Butterfly Conservation believes that the national decline in the number of Duke of Burgundy colonies has been halted from 2010 onwards.
Howard Frost gives a detailed account of the historical records of the Duke of Burgundy in Yorkshire in ‘The Butterflies of Yorkshire’ There were records up to the 1870s from places along a ridge of Jurassic limestone which stretched from near Doncaster in VC 63 to near Tadcaster in VC 64 but all subsequent Yorkshire records have come from the ‘Tabular Hills’ on the southern edge of North York Moors in VC 62 where a band of Jurassic limestone runs for about 30 miles from Sutton Bank near Helmsley through Kirbymoorside and Pickering to Scarborough in the east.
The Duke of Burgundy always appears to have had a limited distribution within this area. Parks and Kirtley reviewed all the available historic records from this area in 1994. There is a 1956 record from Kirbymoorside and two records from the Scarborough area the most recent being from Silpho Quarry in 1978 but apart from this almost all hist historic and current records come from two areas, one north of Helmsley and the other north of Pickering (as shown on the map below).
The Helmsley Area
The butterfly was only recorded at three known locations north of Helmsley in 1993 when a decision was made by Robert Parks and Stephen Kirtley to establish whether it might be more widespread in this area. Through a systematic search process conducted over several years up to 1999 a total of 14 new colonies were found mostly on steep hillsides in valley systems on areas of scrubby limestone grassland. Many of these colonies were small with less than 6 adults being recorded on each visit but one larger colony had peak records of more than 20 adults. Some colonies were on cowslip but most had primrose as the primary foodplant for the butterfly.
The search process was facilitated by access to the North York Moors National Park ‘Phase one habitat survey’. The butterfly appears to have survived in this area because of the high concentration of unimproved limestone grassland habitat patches which allows a ‘metapopulation’ structure to be maintained. Most of the sites are small, isolated, and not grazed and are therefore subject to ‘succession’ to scrub and woodland unless they are managed by removal of invasive trees and scrub. The methods which have been developed in southern England to use carefully managed winter cattle grazing regimes under Stewardship schemes do not appear applicable in North Yorkshire
Management of sites using volunteers began in 1993 but following a comprehensive review undertaken in 2003 by Dr Sam Ellis Regional Officer for Butterfly Conservation a more comprehensive programme of management was initiated using contractors to keep the sites clear of trees and scrub and maintain the high quality limestone grassland habitat.. The aim of this management has been to maintain and increase the habitat on all the sites where the butterfly has been recorded. The large scale management programme from 2003 onwards was initially funded by the North York Moors National Park and subsequently by the ‘Landfill tax’. The funding for contractors ceased in 2015 but since then management has mainly been undertaken on an annual basis mainly by volunteers from Yorkshire Branch of Butterfly Conservation and the National Park.
These Duke of Burgundy sites are all on private land which is used for the raising and shooting of pheasants. The key landowners have supported our work by allowing access for recording and also management purposes. These regionally important limestone grassland sites have been conserved (with the exception of a small number of sites where the grassland has been allowed to develop to scrub to increase cover for pheasants) which will benefit a wider range of insects and plants dependent on the limestone grassland. We do not publicise the location of sites in order to maintain our relationship with the key landowners-only one site in this area has public access.
The Outcome of Recording From 2000 Onwards in the Hemsley Area
The seventeen sites where the butterfly was recorded between 1993 and 1999 have been subject to an annual monitoring programme coordinated by Butterfly Conservation (as well as two small new sites discovered since then). Unfortunately, a decline in the numbers of colonies was noted from 2000 onwards. Eight of these original sites went extinct (including the three original sites where it was recorded in 1993) and the butterfly was only recorded on 6 of the remaining extant sites in 2017. Fortunately however numbers on four largest sites have been maintained and increased in this period. The Duke of Burgundy colonies therefore appeared to be in a process of contraction to a smaller number of key sites rather than being at risk of extinction.
The precise reasons for this decline in the number of occupied sites between 2000 and 2017 remain unclear. It is possible that the original recording of these colonies occurred during a period of favourable weather which allowed the butterfly to extend to almost all available limestone grassland habitat patches some of which were of marginal suitability. Warm winters from 2000 onwards may possibly have made increased sward heights on some of these ungrazed sites and made the primula unavailable for egg-laying by female butterflies.
The annual recording programme of sites was revised in 2018 to include searches of the wider area to establish if the butterfly might have colonized new areas. This coincided with a period of hot sunny weather during the flight period which may have encouraged female butterflies to travel from established colonies to new or former sites. We found that the butterfly had colonised two large, cleared conifer plantations on limestone hillsides close to existing colonies; a single female butterfly was found on one site which had been declared extinct and on another new site, and a single butterfly was found over 2 km from any known site. These results were remarkable because in the course of over 20 years recording in North Yorkshire the furthest we had found a Duke of Burgundy from a known sites was only about 800 metres. In total we recorded the butterfly in 14 locations as against 6 in 2017. The records for 2019 were also excellent with records from 13 sites and peak counts of 53, 59, 43 and 103 on our four largest sites (the highest ever counts for 2 of these sites). The results for 2020 were mixed with low numbers recorded on south facing sites but exceptionally high numbers on one or two north facing sites (including a peak count of 122 on one site!) possibly because were unable to begin recording until mid-May due to Covid 19 restrictions.
Conclusion-the Helmsley area
It is too soon to reach definite conclusions but it appears that after a long period of decline from 2000 onwards the number of colonies in the Helmsley area has begun to increase as the butterfly recolonizes extinct sites and moves to occupy new sites.
The long term future of the butterfly in this area remains dependent upon a long term programme of management of the network of limestone grassland sites on which it is found. Most of the sites are ungrazed and will ‘succeed’ to scrub and woodland without an ongoing programme of management.
The Pickering Area
The butterfly was recorded historically from the Gundale valley system north of Pickering at ‘Haugh Rigg’ where it was described in an article written in 1970 as being ‘probably more abundant here than in any other location north of the Trent’ Unfortunately major habitat changes in particular the planting of conifer trees then led to a severe decline and the last record from Gundale was in 1982. Subsequent searches have failed to find the butterfly in this area until a single female was recorded here in 2019 (see below).
There have also been occasional historic records from Newtondale which is a very large glacial valley lying to the north of Pickering through which the North York Moor railway runs. These records extend from Park Gate near Pickering through Farwarth to about a mile north of Levisham Station where the last record was from 1985.
The butterfly was also recorded at a Ellerburn Bank YWT a limestone grassland nature reserve north of Thornton Dale (SE 853849) but the habitat was not managed specifically for the species and numbers declined from 1988 onwards-the last record for this site was in 1993.
Extensive searches of Gundale Newtondale and Ellerburn Bank in 1993 coordinated by Parks and Kirtley failed to find any evidence of Duke of Burgundy and it appeared probable that the whole Pickering population was on the verge of extinction. There have however been a number of positive developments since then.
Developments in Lower Newtondale since 1993
In 1995 of a Duke of Burgundy colony was found in a growing conifer plantation at ‘Little Park Wood’ in Newtondale about a mile north of Pickering. A total of 15 adults were recorded in that year but numbers declined in subsequent years as the conifers grew (the last record from this site was in 2007).
Howard Frost coordinated a comprehensive search for the butterfly in the Pickering area in 2000 which covered all of the areas where the butterfly had been recorded historically in the wider Pickering area. This area was broken down into 27 one km squares which were searched at least twice in the flight period. Positive results were obtained from 7 different one km squares in Newtondale including Little Park Wood (see above), a nearby railway crossing site and the former site at Parkgate but adults were also found further north near Farwarth and nearby Cross Dyke. The maximum number of butterflies found at any site was 6 and an average of only 3 butterflies was found in each occupied 1 km square. Frost concluded that there was a single metapopulation operating via a network of small colonies linked by tracks, rides, and pathways. He highlighted the significance if the railway as a corridor and said that primroses growing on the side of the track were important as foodplants for the butterfly.
The survey also found 3 butterflies at ‘Pexton Band’ which is an area of cleared conifer plantation adjacent to Ellerburn Bank which was being developed as a nature reserve. It appears likely that this was an ‘undocumented introduction’ Unfortunately the butterfly was only recorded on this site until 2004. This site has however been received ongoing management in the hope that it would be suitable for a reintroduction.
A number of Duke of Burgundy butterflies were found in 2010 in an area of recently planted hardwood plantation near Little Park Wood. Since the site was at risk of being lost as the trees grew permission was obtained from the landowner to create a clearing where the butterflies continue to be recorded up to the present time (2020). This clearing has been extended over time and the adjacent forestry track has been widened over a length of about 600 yards to create a wider ride where the butterfly is also recorded. Butterfly Conservation has also developed a significant area of coppice on the other side of the railway which was first found to be occupied in 2017 and numbers are increasing-there was a maximum count of 10 in 2020.
The hot flight period in 2019 led to Duke of Burgundy butterflies being found up to 3 km from the known colonies in Pickering. A single female Duke of Burgundy was found at Yatts Farm an SSSI in Gundale and the butterfly was also found at Pexton Bank. Unfortunately in spite of a careful search there was no further record for Gundale in 2020 (and the habitat may not be suitable maintain a Duke of Burgundy colony). However four Duke of Burgundy butterflies were recorded at Pexton in 2020. It appears therefore that Pexton Bank is being recolonized naturally and that a formal reintroduction will not be necessary.
Conclusion-the Pickering colonies
Butterfly Conservation has therefore been successful in managing to maintain and develop a small number of interlinked colonies in lower Newtondale north of Pickering. The survival of the butterfly in this area is linked to the management of the area for forestry purposes; the butterfly will move to areas which have recently been clear felled and will use primroses exposed by tree felling for egg-laying purposes until the trees grow and the area becomes unsuitable. The work to develop coppice-type clearings and widen rides has been funded by a number of bodies in particular the Landfill Tax and the North York Moors National Park. This work however needs to continue if butterfly is to survive in this area because the cleared areas are at constant risk of being overgrown by invasive trees, scrub, and bramble. It is hoped that the butterfly will continue to thrive at Pexton Bank which has been managed for several years as a potential Duke of Burgundy site.
The future of the Duke of Burgundy in North Yorkshire
Unfortunately, current farming and forestry practices do not provide suitable habitat for the Duke of Burgundy butterfly and its survival in North Yorkshire is dependent upon a continuing programme of management of the sites where it is currently found. This process, which has been ongoing for over twenty years, has been successful in maintaining Duke of Burgundy colonies in both the Hemsley and Pickering areas.
It is possible to see the butterfly at one site with public access in the Helmsley area and it can also be found in smaller numbers along forestry rides in lower Newtondale north of Pickering and at Pexton Bank but do please keep to public footpaths to avoid conflicts with the landowners on whom we are dependent to continue this work.
Yorkshire Branch has a regular programme of work parties on these sites when we can get access in February and March, details of which are published on the Branch website. We also welcome active recorders who can help with our annual recording programme. For further information please contact Robert Parks Species Coordinator for Duke of Burgundy on firstname.lastname@example.org
 Frost, H.M (2005) The Butterflies of Yorkshire Butterfly Conservation
 Parks,R and Kirtley,S (1994)The Distribution and Status of the Duke of Burgundy Butterfly in the North York Moors area. Unpublished