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Brown Hairstreak in Worcestershire - Bulletin 24

February 2006

Dear Brown Hairstreakers,

After the rush of January records, there are just four new squares to report so far this month: SO9255, recorded last weekend on my way back from the Grafton Wood work party, and SO9862/9962 and 9761 lovingly added by Trevor Bucknall on Valentine's Day! These latter records neatly fill in some gaping holes in the distribution map, while the first record between Broughton Hackett and Crowle is our most westerly egg location so far. Part of the reason for this slow down in new sightings is no doubt the fact that the hedge cutters have been out in force over the past few weeks with a result that it is much more difficult to locate suitable blackthorn. Whereas before Xmas a drive along local lanes provided reasonably good opportunities for egg hunting, most roadside hedgerows have now received their annual haircut and it is becoming much harder to spot likely areas to search. This should not deter people from having a try, however, and hopefully the new map drawn up by Nigel Stone will assist in targeting particular areas. Feckenham School have now joined the growing band of our junior champions and went out with Becky Lashley last week to explore some local footpaths. No eggs were found but lots of promising blackthorn and a good time was had by all which is the main thing.

All the additional squares we have added this Winter has encouraged me (with a little prompting from Harry Green!) to delve into the known history of the Brown Hairstreak in Worcs. Perhaps because of its elusive nature as an adult, there are relatively few reports in the literature. Interestingly, the earliest reference in a book written in 1834 lists Trench Wood near Droitwich as a known location. Trench Wood today, of course, is a nature reserve jointly managed by Worcestershire Wildlife Trust and Butterfly Conservation and is right on the known limit of the current range of the Brown Hairstreak. Indeed one of our local champions, Trevor Trueman, spent 3-4 hours there looking for eggs at the end of January but without success. This follows the reported sighting of an adult on the edge of the reserve back in 2004 and the discovery of eggs by myself just a little way down the road this winter. Although Trench Wood is no doubt very different in character to what it was 170 years ago, I'm sure it is only a matter of time before we can confirm breeding there. There are a number of other 19th century references to Trench Wood and, in 1901, the Victoria County History of Worcestershire lists Wyre Forest and Cowleigh, two areas well removed from the current known distribution. After this date, references to Brown Hairstreak in the county completely disappear and it was only through the painstaking research undertaken by the late Jack Green that the butterfly was "rediscovered" in the old orchard on the edge of Grafton Wood in April 1970. Since that date, especially over the past 10 years, through the efforts of many volunteers, we have built up a picture of its total distribution and we now know it to be found in the low lying area of east Worcestershire concentrated around the former Forest of Feckenham extending currently to 85 1km squares. Undoubtedly, there are more locations to be discovered but it would still be a big surprise if it was recorded outside of a line joining Worcester-Pershore-Evesham-Redditch-Droitwich-Worcester.

Rather intriguingly, Jack Green in his "Practical Guide to the Butterflies of Worcestershire" (still available via WWT) published back in 1982 lists the 10 km squares SO84 and SO94 (both outside the current known range) as holding the butterfly but gives no further detail. A clue to the location of eggs within the SO94 square comes in a subsequent article written by Jack for the "Entomologists Record" in which he refers to eggs being found at "a perimeter dispersal point on a disused airfield". Pershore Airfield would seem the most likely and Trevor and myself did have an initial search there back in January but without success. It is references such as these which makes work on the Brown Hairstreak often seem like the unfolding of a modern day detective story. Just what discoveries still await around the next corner?

I am off on holiday for the next couple of weeks but please continue to email me with any sightings or other items of interest ready for the next ebulletin in early March.

Mike Williams,
Brown Hairstreak Species Champion