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No. 54 NEWSLETTER Spring 2003

WEST MIDLANDS BRANCH, BUTTERFLY CONSERVATION

 

Conservation Corner
 

I am writing this piece only a couple of days after the West Midlands Branch Conservation Committee meeting which is a very enjoyable twice yearly event and one where you find out about lots of new things going on in the region as well as the huge level of commitment and enthusiasm of branch members in the various counties. The meetings are always very well attended and we will soon be running out of both space and chairs - I hope it will always stay like this! As Corinna Gregory has recently understandably stepped down as minute taker following the birth of her son Oliver we are now looking for somebody else to take on this role. If you can spare two Saturdays a year, can take notes and transcribe them onto a computer, would like the opportunity to meet the members of the branch committee and learn a lot more about what is going on in the branch then please let me know - your help would be very much appreciated.

I have recently been given several reports based on 2002 work which have provided some fascinating results: Dave Grundy undertook a study of the Common Fanfoot at the Wyre Forest. This is a moth which has suffered a massive decline over the last 30 years and is now only known from 7 sites, nationally. Little was known about the ecology of this species prior to Dave's work in the Wyre Forest and as a result of his work we already have a lot more information to go on. Dave recorded 53 adults and 65 larvae during his project (which was amazing considering that few wild larvae had ever previously been found). He found the most effective way of recording larvae was to search branches hanging from oak trees at head height, that had been snapped by hand in May/June. Dave suggests that this method of larval searching should be employed on all known and possible Common Fan-foot sites across the country in 2003 (but if you are going to try finding some Common Fan-foot larvae using this method please make sure you have permission from the landowners before snapping any branches). I would like to congratulate Dave on his enterprising project and I am sure I will now never look at snapped branches in quite the same way again!

Peter Boardman undertook a ten year review of Lepidoptera and Odonata monitoring at Fenn's, Whixall and Bettisfield Mosses NNR for English Nature in 2002. The most immediate thing that hits you when reading this report is the huge amount of effort that has been expended. During the period 1993-2002 a total of 20,624 individual butterfly records and 68,417 Odonata records were amassed on transect walks across the mosses. Thirty butterfly species have been identified during this time (with two species only being recorded by off transect means) with additional moth survey work adding to the species list and highlighting rarities such as the Dingy Mocha and the Northern Footman. Although Large Heath butterfly numbers appear to not have increased substantially during this ten year period (33 recorded in 1993 on Transect A compared with 32 in 2002), Peter considers that this transect is failing to recognise a real rise in numbers due to the methodology used in transect recording (and the fact that the weather has generally been poor during the peak flight season for the past three years). For these reasons, Peter now suggests that timed count methodology may be a better way of monitoring the Large Heath upon Fenn's and Whixall Mosses in the future.

I have also completed several reports based on work done by myself and others in 2002 (several of which will be detailed in the next newsletter). These project reports include the study of the Pearl-bordered Fritillary in the Wyre Forest where a comparison of numbers at 33 sites in 1997 and 2002 found that at only site did they seem to have increased in size (compared with another 9 sites being stable and 24 sites where they appeared to have declined in size). Nevertheless, the 2002 survey was not all bad news as it also identified 9 additional sites and areas in the Wyre Forest which are now important for the Pearl-bordered Fritillary with singletons being recorded in four additional places. 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 Forest Enterprise 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 to increase the amount of land in the coppice cycle and to see whether open space can be maintained as suitable breeding habitat by management such as rotational scarifying and cutting.

A survey of Dingy Skipper in the Telford area in 2002 also presented a slightly depressing picture as this species has been lost from at least seven sites and it has declined almost to the point of extinction on two others in the last 5-10 years. Nevertheless, as there are still at least five sites/areas the where the situation for Dingy Skipper has probably remained stable over this time period and one site where there has been a large increase in numbers (following ground disturbance work carried out over 5 years ago to try to encourage heathland regeneration) there is no doubt that the Telford and Wrekin area can still be considered to be an important regional stronghold for this species. There is an urgent need for another trial management programme to be set up on Telford and Wrekin sites to try to improve the habitat for Dingy Skipper (as well as for Green Hairstreak) as the results from the 2002 survey show that Dingy Skipper numbers in particular, can very quickly decline once the habitat quality falls. This management programme should include scrub removal and surface stripping (to try to increase the amount of sparse vegetation and especially bare ground, which is readily colonised by bird's-foot trefoil).

I hope this gives you a flavour of the sorts of projects that have been going on as it is now time to ask for help with some projects this year. A special plea therefore for volunteers to turn up at the two recording days planned (see Events Diary) for the Small Pearl-bordered Fritillary in the Staffordshire Moorlands (in the Consall Nature Park area and the Churnet Valley). Although the area we need to cover here is potentially vast we hope to be able to reduce this down to a manageable amount by going out to survey for violets before the flight season of this butterfly. Adult survey will then largely be restricted to areas where violets have been seen but even then we shall still need as much help as possible to cover this poorly recorded area of Staffordshire.

A second plea is for help surveying the Malverns for High Brown Fritillary and re-visiting sites where this species has been recorded in the last twenty years. This is particularly important to do in the light of the sheep grazing regimes currently being implemented by the 'High Brown Hills' project as they may be improving the habitat for this endangered butterfly. We have therefore organised two recording days for the High Brown Fritillary in the Malverns which we hope will be supported by branch volunteers and one for the Grayling in the same area (as this is an under-recorded species with the Malverns being thought to be an important regional stronghold).

Please do try to join us on at least one of these surveying days in 2003 as we would very much appreciate your help.

Jenny Joy