Introducing the Brown Hairstreak

The Liz William’s Butterfly Haven (a designated Local Wildlife Site) is managed by a group of nature enthusiasts, the “Friends of the Liz Williams Butterfly Haven” Their aim is to manage the site as both a teaching and learning resource for the school and also as a site of nature conservation importance for the local community.

Although the site boasts sightings of 89% of all the butterfly species recorded in the city of Brighton & Hove, only one of these species has been deliberately introduced, the Brown Hairstreak The national charity Butterfly Conservation describes its conservation status as:

Section 41 species of principal importance under the NERC Act in England

Section 7 species of principle importance under the Environment (Wales) Act 2016

UK BAP status: Priority Species

Butterfly Conservation priority: High

Protected under Schedule 5 of the 1981 Wildlife and Countryside Act (for sale only)

Overleaf, Dr Dan Danahar tells the story of the remarkable success this group has had with this species.

In the late summer of 2020, Max Anderson informed me of a cricket pitch in Portslade where there was a healthy population of Brown Hairstreak (Thecla betulae) butterflies The females of this species, once mated, lay their eggs on their hostplant, Blackthorn (Prunus spinosa) This takes place in August/September, where the eggs reside until the caterpillars hatch the following March/April.

However, on this particular site a keen groundsman annually cuts the egg-bearing twigs from the bushes because the Blackthorn grows onto the periphery of the cricket ground, intruding onto the area of play. Max quickly realised that this meant a significant number of Brown Hairstreak eggs were being removed annually

In 2014, Jeremy Burgess had reported this species from Patcham and in 2015 Jamie Burston videoed the butterfly from the same location. This is just a stone’s throw away from the Liz William Butterfly Haven and so I had decided to plant some Blackthorn on the reserve, in the hope that the butterfly would colonise the site Sadly, in the intervening eight years this never happened, but the Blackthorn grew well and by the time that Max told me about the Brown Hairstreak problem at the Portslade cricket pitch, the answer to this issue seemed to me to be simple: I suggested we translocated the eggs from the one site to the other

So, in the winter of 2021, Max and I collected 40 eggs and individually attached them to the blackthorn bushes of the Liz Williams Butterfly Haven, using black electrical insulating tape In the summer of 2021, Tony Gould photographed the first female Brown Hairstreak on the Liz Williams Butterfly Haven site and in the winter of that year we found wild laid eggs on the haven.

Subsequently, we took another 40 eggs from the donor site during the winter of 2022 and in the summer of this year we observed three females, each seen two weeks apart, i e they were three different individuals.

On the 28th January 2023, a quick search around the Liz Williams Butterfly Haven revealed about 15 wild laid eggs distributed widely throughout the site Then Max, Becky Claire, John Miller and I revisited the Portslade cricket pitch and collected a third batch of 40 eggs, which we once again transferred to the Haven

It appears that this experiment is working well!