A full version of this article appears in the magazine.

The Brown Hairstreak Thecla betulae is one of Wales’ most fascinating butterflies. It is associated with lowland clay soils and has a patchy UK distribution. By 2004 targeted egg surveys showed a range contraction of 50%. The survey results for the 5-year period up to 2009 are not yet fully analysed, but anecdotal evidence from surveys by Butterfly Conservation volunteers does not suggest any recovery.

 

Butterfly hunting in deepest winter

In the winter of 1999 we revisited the roadside hedges where internationally famous lepidopterists Jeremy Thomas & Tom Tolman had found eggs during the winter of 1987. Once we found one egg in a 10km square (proving occupation), we moved on. We quickly worked through more than fifty 10km squares comprising the pre-1987 range. This was a quick and efficient, but a very superficial method of assessing the extent of range.

 

Refining the winter survey approach

The next stage was to explore the strength of these local populations. We embarked on what became an annual winter egg survey, assessing population strengths in a 1km radius of recent egg records. We focussed on Tir Gofal farms or smallholdings and always sought permission. Some farmers do think we are crazy wanting to look for butterfly eggs in their hedges in deepest winter!

 

The habitat, location of eggs and area searched have been mapped every year and, by modelling the landscape area using each record from 1995 to 2009, we can calculate that there are approximately 200,000 hectares of lowland south west Wales which would support Brown Hairstreak if there was sympathetic hedge/scrub management in place.

 

'Butterfly Friendly Hedgerows' – a pilot community project in the Teifi valley

In winter 2009/10, we secured funding from Heritage Lottery Funds ‘Awards for All’ scheme to run a pilot project in Carmarthenshire. The aim was to encourage an entire local community to embrace butterfly friendly hedgerows and land management. We chose the Llangeler area, close to the Teifi . It had several landholdings with low intensity hedge management and over 200 eggs had previously been found but with much more potential land to search.

 

Delivering the message

We spoke to or delivered invitations to 40 people/properties, with 18 people attending our two events at the local village hall. The events were aimed at everyone, showing what could be done in various situations such as gardens, community fields, green lanes, low intensity traditional farms, modern commercial farms and country businesses. From feedback forms and subsequent follow up, we were delighted to be invited to survey new land holdings (plus two people who went off to survey their own land) and eight new people have volunteered to join our survey team, five of whom have regularly been out with us.

 

Delivering management

As part of the project we were offering to help landowners coppice old blackthorn, keeping a steady supply of young plants/shoots for Brown Hairstreaks. We identified three work tasks that were acceptable to – indeed gratefully encouraged by – the landowners. At a holiday cottage let, assisted by our able local contractor, we carried out coppicing at the back of a developing thicket, having first placed coloured pegs to identify (and therefore retain) the younger plants at the front which bore the current year’s eggs. Four volunteers helped clear away the brash and protect the re-growth from horses. The owner prides himself on his wildlife friendly approach, which helps his business, as clients like to know what wildlife is being fostered.

 

We carried out a similar task at another smallholding. The owner was delighted that three of his smaller valley bottom fields held over 80 Brown Hairstreak eggs. This adds to his holding’s species total, much of which he manages for its species-rich hay meadows.

 

At the museum, virtually half of the eggs were in the smallest field alongside the woodland, laid on suckering/seeded young plants. The problem was vigorous bramble runners smothering the blackthorn. So we set to work, to remove as much as possible over two half days. In so doing, a further 15 eggs were revealed, not accessible on initial survey. We are looking forward to searching for caterpillars in late May/early June and to watch for the female Brown Hairstreaks descending to egg lay in August & September.

 

Displaying the discs and logos

All these holdings have proudly displayed our 'Butterfly Friendly Hedgerows' discs around their properties. The discs tell the world, particularly neighbours, visitors and passers-by (and potential flail contractors) that wildlife, and particularly this distinctive local butterfly, is being encouraged. All farms surveyed will receive a map showing habitat quality and egg numbers this year, field by field, together with a reminder of suggested management (including a rotation plan where applicable). An electronic version of the disc is also available for use on owners’ websites and letterheads.

 

So, how many eggs and new sites?

We finally notched up a total of 573 eggs, across 22 different land holdings. Of these, 16 were new sites and put six new occupied 1km grid squares on the Brown Hairstreak records database. At least 90 volunteer days have been put into the project to date.

 

What now?

Although it’s still early days, this winter’s efforts around Llangeler have been very worthwhile. We’d like to try to ensure that momentum is maintained, with opportunities to develop and widen the project throughout this year and in future winters. Several unique opportunities have opened up and the area looks set to become established as a Brown Hairstreak success story. It all depends on landowners, volunteers and goodwill; at the moment we have a bounteous supply of all three.

 

After ten years of talking to several hundred landowners we have learnt a great deal. There have been major finds of previously unknown populations, particularly 560 eggs in 2004 on one farm west of Carmarthen, 350 eggs in 2007 on one farm in Cothi valley (until it was all flailed) and 573 eggs in 2010 around Llangeler in the mid Teifi valley. We now have a dozen landholdings in completely sympathetic management, entirely by unwritten voluntary agreement.

 

Food for thought

There is little doubt that Brown Hairstreaks survive in south west Wales largely because of small landowners who are not managing their land or hedges intensively. There is also a limited but positive contribution from low intensity silage or hay fields, cropped fields, agri-environment schemes and a number of nature reserves. However, that leaves out most of the commercially farmed landscape, where devastating annual hedge flailing is epidemic. Studies have shown that annual hedge flailing destroys, on average, 80% of eggs each year, resulting in local extinction in three years. Other studies have found that, for good quality hedges, trimming on rotation over a 3-4 year period saves landowners up to 60% in costs. Why are so many landowners wasting money and fossil fuels in the trimming of all their hedges annually? Some of this is because of fear of highway enforcement letters regarding roadside hedges, some of it is contractors wanting regular work and some of it is peer pressure and misguided notions of tidiness. Annual cutting of roadside hedges may be necessary but can the rest really be justified? With high fuel costs surely a more relaxed view of what a tidy hedge should look like saves money as well as promoting wildlife.

 

Richard Smith is Events Co-ordinator for Butterfly Conservation’s South Wales Branch

Russel Hobson is Head of Conservation, Butterfly Conservation Wales.

 

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