Brown Hairstreak Bulletin 112
It is always good to finish off our egg counts at Grafton Wood on a high and we certainly achieved that with our final survey day on 18th January when we found an incredible 368 eggs in and around the wood. 170 of these eggs were actually within the wood itself which is a record by some margin and is a result of the terrific rideside management that has been undertaken by volunteers over recent years which has created lots of ideal habitat. The second hotspot was just outside the wood on adjoining farmland where a scrubby and very sheltered margin to a field produced very good numbers. The egg hunt itself was well attended and it was good to welcome several new faces. Two days earlier, our annual visit to Morton Stanley Park in Redditch proved very successful with again record numbers of eggs. This is the third consecutive year that eggs have been found in the Park which suggests that the butterfly is becoming established there with eggs found over a much wider area. We were also pleased to find an egg beyond the park boundaries which was a new 1km square record (SP0365) and then later in the day another new square record (SP0564) in the Oakenshaw area which represents the furthest east in Redditch that the Brown Hairstreak has been recorded. Congratulations to local Hairstreak Champion Jenny Tonry who was responsible for both these finds and, in the process, chalked up our 200th 1km square. In recent years, we have developed a good relationship with Redditch Council and are hopeful that we can work with them to encourage further the spread of Brown Hairstreaks in the town.
Another particularly productive area for Brown Hairstreak eggs this winter has been around Bradley Green especially along Hollowfields Lane, as reported in the last ebulletin. We made a return visit to the area in early February and increased our egg count there to over 200 eggs. An interesting discovery were two Brown Hairstreak eggs laid on what appears to be hawthorn which we have marked for further investigation. Don't imagine that this is likely to turn out to be a new discovery to science, more likely a rather confused female who did not pay sufficient attention at Hairstreak school! Egg searching is likely to continue through to the end of March. I am away for much of this time looking for butterflies (and gorillas!) in Uganda but, if you are interested in joining in, then contact Simon Primrose on firstname.lastname@example.org With our core egg counts all completed, we should have more of a chance to search some new areas where Brown Hairstreaks have not been previously recorded.
On 20th Feb, the Thurs Streakers were joined by volunteers from Worcestershire Countryside Service to work on a stretch of over-mature blackthorn that was blocking a public footpath near Shurnock. As well as clearing the path, our work (see photos) should result in lots of regenerating blackthorn that will provide excellent breeding habitat for the Brown Hairstreak. At the same time, we were able, with permission from the local farmer, to gap up an existing hedgerow with blackthorn suckers left over from our planting at Bourne Close in Flyford Flavell before Xmas. Thanks to Simon and Amanda Hill from Worcs County Council for organising a very positive day which should bring real benefits to the Brown Hairstreak. Geoff Thompson has been undertaking egg searches in the area around Shurnock for several years and this winter is proving once again that the butterfly is doing really well in this part of the county.
It will be interesting to see what impact this very wet and mild winter has on butterfly numbers. Certainly, the summer of 2013 showed a major improvement on the previous year and Butterfly Conservation nationally has just produced figures drawn from their Wider Countryside Butterfly Survey which show major increases in numbers for many species including butterflies like the Small Tortoiseshell which has been much less common in recent years. As we reported at the time, there seemed a very good emergence of adult Brown Hairstreaks in Worcs last autumn and we now know that this was followed by generally excellent numbers of eggs being laid. Fortunately for the Brown Hairstreak, the fact that it overwinters as an egg means that it is less susceptible to flooding than many species. There is an absence of evidence on how well caterpillars can survive submersion in water over a prolonged period and this may be the year when we find this out! After the events of recent weeks, we certainly deserve a good summer. This year's Brown Hairstreak Open Day at Grafton Wood will take place on the Sunday of the Bank Holiday weekend, 24th August and we must hope the sun will be shining on that day at least.
Brown Hairstreak Species Champion,
West Midlands Butterfly Conservation