White Letter Hairstreak by Ben Keyboard

Sheffield & Rotherham Wildlife Trust calls on Council to save Chelsea Road elm tree, whilst trying to save butterfly colony

Despite considerable efforts by Sheffield & Rotherham Wildlife Trust and many other interested parties to seek a more sympathetic approach to the management of the Chelsea Road elm tree, Sheffield City Council plans to carry out pruning next week (week commencing 12 February), with a view to felling in the future.

The Trust has agreed to assist the Council with the translocation of White-letter Hairstreak butterfly eggs from the pruned branches as part of a butterfly mitigation plan, in an effort to try and save the colony of this declining priority species.

Liz Ballard, Sheffield & Rotherham Wildlife Trust’s CEO, said:

“We remain strongly opposed to the Council’s decision to fell the Chelsea Road elm. Since 2015, we have campaigned alongside other organisations, local street tree groups and residents to save this particularly important tree. This tree has survived for over 100 years, despite the ongoing threat of Dutch elm disease and numerous roadworks, and is both a key feature of the area’s street scene and a part of Sheffield’s natural heritage.”

In January 2016 the Trust highlighted to the Council that the rare 120-year-old Huntingdon elm supported a colony of the White-letter Hairstreak butterfly, which is a Priority Species in the UK Biodiversity Action Plan due to its 96% decrease in abundance over the last 40 years, of which 77% has occurred since 2005. (State of UK Butterflies report, Butterfly Conservation).

As well as challenging the decision to fell the tree, the Trust asked the Council to recognise the presence of the White-letter Hairstreak butterfly in the tree canopy and protect the colony under its legal duty in the Natural Environment Act to conserve biodiversity.

Liz Ballard said:

“The proposed felling of this tree illustrates many of the wider ongoing issues we have raised with the Council about the current street tree programme, including the impact of such a large and rapid felling programme on the city’s wildlife and natural environment. This tree in particular supports a colony of nationally important and endangered White-letter Hairstreak butterflies that will be lost through canopy reduction and felling. Keeping the elm tree is the simplest approach to retaining the butterfly colony it supports.”

The presence of the butterfly was recognised by the Council over 18 months since the issue was first raised. As a result, the Council agreed to developing and delivering a butterfly mitigation plan, in consultation with Sheffield & Rotherham Wildlife Trust and Butterfly Conservation.

White-letter Hairstreak, by Ben KeywoodLiz Ballard said:

“In the interests of securing the best outcome for wildlife, we have decided to assist with the Council’s butterfly relocation plan, involving our staff who have previous experience of White-letter Hairstreak egg relocation. We hope this will help to improve the chances of success for securing a future for the butterfly colony.”

When the Council’s contractors Amey begin the pruning, the Trust will save the high canopy cuttings, searching for White-letter Hairstreak eggs. Once identified, these small branches will be set aside and relocated to suitable receptor trees. Sheffield Council Ecology Unit has committed to monitoring into the future to assess the success of the egg relocation, which cannot be guaranteed. It is important that pruning is carried out as soon as possible, before the eggs hatch, in order to give the translocation of the eggs the best chance of success.

Liz Ballard said:

“Given the circumstances we believe it is an important course of action for us to pursue. The Council will pay costs for the involvement of our staff and we will continue to call on the Council to re-assess and reconsider the need to ultimately fell the Chelsea Road elm tree.”

Anyone interested in volunteering to help relocate the butterfly eggs should contact Sheffield and Rotherham Wildlife Trust on 0114 263 4335 – the Trust will provide equipment and light refreshments. Only patience and good eyesight are needed!

For further information about the butterfly relocation plan for the White-letter Hairstreak butterfly and our correspondence with Sheffield City Council, visit our street trees page or download our Q&A here.

The case for saving the Huntingdon Elm

The Council’s own Independent Tree Panel (ITP) report for this tree, dated 22 July 2016 (publicly released over a year after being submitted to the Council, despite written reassurances to the Trust from Cllr Bryan Lodge that this would not be the case) stated that there was “no arboricultural need to remove this tree”.

Additionally, independent tree inspection reports commissioned in October 2016 – but only recently released following repeated requests by the Trust – gave no reference to the tree being immediately unsafe, presenting a danger to the public or having a short lifespan.

White-letter Hairstreak butterfly and the Huntingdon Elm

The White-letter Hairstreak (Satyrium w-album) butterfly is so called because of the markings on its wings that suggest a scrawled letter ‘w’ (indeed it has previously been called the White w-Hairstreak). This helps to distinguish this butterfly from other hairstreaks such as the Black. The White-letter Hairstreak is a species that thrives in the high canopy of mature trees, drawing on nectar from flowers and laying eggs on small branches to overwinter. Elm tree flowers are the main recognised food source of the White-letter Hairstreak. As well as English elm, the butterflies are associated with Wych elm (which are Dutch elm disease resistant) and hybrid elms. The Huntingdon elm is an example of a hybrid elm, thought to be partially resistant to Dutch elm disease because of being a cross between Wych elm (resistant) and English elm (not resistant). With so few mature elm trees remaining in the landscape because of Dutch elm disease, a mature elm tree in any location is a rare sight.

There has been a marked decline in the abundance of White-letter Hairstreak, estimated as a loss of 99% of the population over 25 years (1984-2003 Defra/JNCC UK Priority Species Report). Being a high canopy butterfly, it can make it difficult to spot this elusive butterfly and assess population changes but given the loss of mature English elms from England in the 1970s onwards, it is not surprising to see such a decline in this species. The butterfly is considered to be endangered and is listed on the Butterfly Red Data List for the UK.