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 SURVEY OF THE WYRE FOREST FOR
THE PEARL-BORDERED FRITILLARY
(Boloria euphrosyne)
2002

Photo - Peter Boardman

Contract Survey Report to English Nature, Forest
Enterprise and West Midlands Butterfly Conservation

Dr Jenny Joy


December 2002

 

Acknowledgements

I am very grateful to English Nature for funding part of this project (both through a Biodiversity Action Grant from Peterborough and through the local EN team at Hereford and Worcester) and to Forest Enterprise for help with expenses (through Assistance for Wildlife Studies). I also acknowledge some financial support from the West Midlands Branch of Butterfly Conservation.

A huge thank-you to all the recorders who contributed their voluntary time and effort and without those results this report would not have been possible. They were John Brown, Trevor Bucknall, Caroline Bulman, Ruth Edwards, John Deakin, Dean Fenton, Neil and Corinna Gregory, Dave Grundy, Colin Hill, Frank and Pat Lancaster, Adrian Miles, Phil Rudlin, Sylvia Sheldon, Richard Southwell, John and Miriam Tilt, Mike Williams, Rosemary Winnall and four members from the Buckinghamshire Branch of Butterfly Conservation.

Special thanks are also due to Frank and Pat Lancaster, Phil Rudlin and Rosemary Winnall for both helping me to plan this project and for their support on the ground, to Matthew Oates for his advice, to Terry Higgins and Frank Lancaster for supplying me with their transect data, to Jim Chance (Butterfly Conservation (BC) West Midlands Branch Recorder) who supplied me with records from the BC database which enabled me to target my recording and to Caroline Bulman, Tom Brereton and Katherine Stewart (BC, Wareham) who responded to my numerous requests for information on the Wyre Forest.

Caroline Bulman, Tim Dixon, Matthew Oates, Phil Rudlin and Mike Williams also provided useful comments on an earlier draft of this report which have been incorporated where possible.

 

Summary

A comparison of the 1997 and 2002 Pearl-bordered Fritillary timed count data from the Wyre Forest initially presented a depressing picture. At only one site does the Pearl-bordered Fritillary colony appear to have increased in size, at 9 sites they appear to be stable and at 24 sites they appear to have undergone decline. These results cannot be attributable to the weather as there was fine weather from mid March onwards in both years (suggesting comparable levels of adult emergence) and the timed counts were carried out under similar weather conditions. The majority of these sites (76%) currently only support small colonies, 24% support medium sized colonies with no sites continuing to support large colonies.

Nevertheless, the 2002 survey has identified 9 additional sites and areas which are now important for the Pearl-bordered Fritillary with singletons being recorded in four additional places. Colony size assessment suggests that six of these additional colonies were small and three were of medium size.

One feature that many of the additional Pearl-bordered Fritillary sites identified in 2002 share is that they contain an extensive area of clear-fell or recently opened up area of land. As the extent of clear-fell planned for the FE section of the Wyre Forest in the future is much reduced (due to the planned reversion of the forest to broad-leaved woodland) and the level of coppicing may also be lower here than originally envisaged (due to slow coppice re-growth), the impact this will have on the Pearl-bordered Fritillary in the future needs consideration. Some possible ways forward may be a) to increase the amount of land in the coppice cycle b) to see whether open space can be maintained as suitable breeding habitat by management such as rotational scarifying and cutting.

Bugle was found to be the major nectar source utilised although adults were seen feeding on seven other plant species including tormentil and bird's-foot trefoil. Egg laying behaviour was only observed at three sites with two eggs being located at one site. Interestingly, in 60% of cases where adults were found, violets abundance was recorded as rare (in contrast to 37% of cases where violet abundance was frequent or 3% of cases when they were abundant). This result may reflect the time of year the recording were made and the fact that is was difficult to look for butterflies and search for violets simultaneously.

Two transects continued to be recorded in the Wyre Forest during 2002 (Wyre Forest East and Wyre Forest West). While there is no doubt that it is important that these two transects continue, it is suggested that an additional ten sites are monitored annually by timed counts. The initial sites proposed are the IMI Compound, FE Pipeline, FE Longdon Orchard, FE clear-fell above the Experimental Pond, FE Wimperhill Deer Lawn and Wildlife Corridor, FE Railway Line, NNR Railway Line, NNR Withybed Wood, NNR Longdon Wood and one of the NNR coppice coupes. Ideally this list should be reviewed annually (with any unsuitable sites being removed and newly created areas of habitat included) so that it adapts to changing circumstances.

Additional priority work for 2003 should ideally include a) violet assessment in April on all key Pearl-bordered Fritillary sites (giving priority to medium colonies) b) identification of Pearl-bordered Fritillary breeding areas and types of habitat involved (e.g. deer lawns, meadows and pipelines etc.), c) expansion of the FE experimental management programme and d) assessment of the use of scallops by Pearl-bordered Fritillary. Further work on Pearl-bordered Fritillary breeding sites (including violet assessment) in the Wyre Forest is particularly important as this information could be used to 'guide' future management as well as helping to determine whether the Forest of Feckenham area of Worcestershire is in a suitable condition for a re-establishment.

It was disappointing to record no Argent & Sable or Drab Looper Moths as part of the 2002 survey. Nevertheless a number of other interesting moth species were recorded. These included Small Purple-barred (a species which is rare in Shropshire and in Worcestershire was last recorded in the Wyre in 1991), Marbled White-spot (the Wyre Forest being a well known site for this uncommon species) and Schiffermuellerina grandis at Ribbesford Woods. This last species feeds on dead wood, is classified as a pRDB1 species and is currently only known from Somerset and south Devon.



If you would like to read the full report of this project please contact Jenny Joy on 01952 249325 or write to The Croft, Off Haygate Road, Wellington, Telford, Shropshire, TF1 2BW.


 

 

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