Brown Hairstreak Bulletin 113
Dear Brownhairstreakers,
The difference a year makes. Looking back at our ebulletin of a 12 month ago, we were bemoaning a very late spring with cold and wet weather being the norm. In the case of the Brown Hairstreak, blackthorn was late flowering and we did not find our first hatched egg until 1st May. This year could not be more different with blackthorn well in flower from early April and Paul Meers reporting the first "hatchling" of the year on 13th April at Feckenham Wylde Moor which is our earliest date ever in Worcs. By the time the Thursday Streakers got along later in the week, the majority of the marked eggs there had already hatched. Some recent research in Holland has raised concerns as to whether early springs might mean that eggs hatched before leaf buds were available for the caterpillars to eat http://depot.knaw.nl/8793/1/DeVries_ea_4877.pdf but our own observations this year showed little support for this idea. In almost all cases, there was an available food source within a few centimetres of the hatched egg. Finding the newly emerged caterpillars, however, is another matter, although Paul does seem to have developed a real skill in this area, after his success last year, and found another couple (see photo). Last year, Brown Hairstreak caterpillars were only half grown by the middle of June but, if the good weather holds, I suspect things will be rather different this time.
Over the last couple of months, we have been looking for eggs outside the current known distribution of the Brown Hairstreak and have had some success with eggs located in SO9564 north-east of Hanbury Church and then SO9350 at Peopleton Village Hall. While there is always a chance that "new" discoveries are just situations where the butterfly has been overlooked in the past, both of these sites are areas where we have consistently searched in the past and are therefore more likely evidence of further edge of range expansion. Something that is undoubtedly helped by the fact that more farmers have been entering stewardship schemes or are otherwise managing land with the needs of the Brown Hairstreak in mind. In this context, we were delighted to hear from Rob Havard who farms near Himbleton that, following our visit over the winter, he has planted around 600 new blackthorn plants and coppiced 200m of hedgerow, Projects such as this can make a real difference to the Brown Hairstreak and, as we saw with the new planting carried out at Bourne Close (see ebulletin 110), can bring immediate dividends. Another recent example of short-term success came from Foomer's Way near Upton Snodsbury, which the Thurs Streakers visited in January 2013, and where the local footpath group had undertaken some subsequent clearance work. Hilary Williams, the footpath warden who we had met on the day, has now found Brown Hairstreak eggs at twelve locations along a 150m stretch of cleared footpath which is great news.
Not all our efforts at finding new egg locations meet with success. In early April, we made another effort to find new locations for the Brown Hairstreak within Redditch concentrating on the area around the Tesco superstore in Headless Cross. Although there was plenty of suitable blackthorn, we found no eggs offering again conclusive proof that, while the Brown Hairstreak has in past frequented the car park of the Waitrose store in Droitwich, it does not shop at Tesco. From time to time, when looking for Brown Hairstreak eggs, we come across the eggs of other insects which also lay their eggs on blackthorn and we did so again on this occasion. The two commonest are Blue-bordered Carpet moth and Green-brindled Crescent which like the Brown Hairstreak are very distinctive in shape and easily recognised. Blue-bordered Carpet, which is much commoner on blackthorn than Green-brindled Crescent, has a much more oval and flatter egg and lacks the sea urchin shape of the Brown Hairstreak. The attached photo from Jenny Tonry (mixed double) illustrates the differences very well although it is extremely unusual to see the two eggs sitting alongside one another in this way. The eggs of Blue-bordered Carpet over-winter, like the Brown Hairstreak, and hatch at a similar time, although they are sometimes laid on alder as well as blackthorn. The moth is fairly widespread in lowland Britain but, again like the Brown Hairstreak, never seems numerous as an adult.
Members of Butterfly Conservation will have recently received the Spring issue if The Comma which, as always, is a good read with plenty of Brown Hairstreak interest. There is a lot going on in Hairstreak land over the summer beginning with an information stall and guided butterfly walks at the Wildlife Trust's Tiddesley Wood open day on Sun, 4th May and an afternoon butterfly walk at Grafton Wood on 13th July. As previously announced, this year's Brown Hairstreak open day at Grafton Wood is on Sun, 24th August starting at 11 am with guided walks in the morning followed by a light lunch at Three Parishes Village Hall. The following day we shall be running a stall in St. Andrews garden, Pershore as part of the Plum Fayre. For further details go to www.westmidlands-butterflies.org.uk The Comma also announces plans to produce a new edition of our ever popular butterfly walks booklet. The few remaining copies of the existing booklet will be on sale at the Tiddesley Wood event or can be ordered from myself at £5.95 per copy including postage. If you have a favourite butterfly walk that you would like to share with others and see featured in the new guide please get in touch (@email). One event not finalised in time to appear in The Comma is our annual blackthorn bash which this year takes place on Sun, 3rd August meeting at Grafton Flyford church for 10 am. This is your chance to try your hand at a little practical management work to benefit the Brown Hairstreak and is ideal for those who have not tried this before.
Enjoy the very pleasant spring weather while it lasts with hopes that it heralds a good summer full of butterflies.
Mike Williams,
Brown Hairstreak Species Champion,
West Midlands Butterfly Conservation