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Small Blue by Mark Searle

UKBMS Summer Newsletter

Dear UKBMS and WCBS surveyors, Regional Coordinators and WCBS Champions,

As I write this, we’re emerging from a sunny, warm, and dry May - England’s second warmest May on record. This has been quite a contrast to the weather we experienced last year, and I’m sure Surveyors have welcomed the improved conditions for walking transects, with increased butterfly activity adding to the rewards. 

Below we have updates about new survey methods, an exciting find on a transect and reminders about staying safe whilst doing your surveys.

New survey methods introduced

The UKBMS currently reports national trends for 58 of the 59 regular UK species. But we recognise that the data for some priority species can be improved, as their ecology isn’t always well suited to the standard transect method. To address this, staff and volunteers have been trialling new approaches. Draft guidance for two of these methods is now available on the UKBMS website and we welcome your feedback before finalising them for next year.

• Black Hairstreak UV Monitoring – With a short adult flight period which is mostly spent high in the tree canopy, Black Hairstreak can be difficult to pick up with standard transect methods. A supplementary method using UV flashlights to locate the photoluminescent larvae has been developed by BC volunteers and staff. Draft guidance is now available on the UKBMS website, including details on the required safety equipment.  

Black Hairstreak larvae and pupae at increasing stages of development under natural light and UV torch light (a-d, larval instars 1 to 4; e-f, early and completed pupae) – courtesy of Gareth Tilley (University of Sussex).  

• Northern Brown Argus Egg counts – This species is difficult to monitor as it occurs in small, scattered colonies in Scotland and northern England where poor weather adds to the challenge of finding adults. However, its eggs - which are laid on the upper surface of Common Rock-rose leaves - are relatively easy to spot and can be surveyed even when adult activity is restricted. Senior Ecologist Patrick Cook has led two years of trials with volunteers to refine this method. A recording of a recent online training session is available on Butterfly Conservation’s YouTube channel and draft guidance is available on the UKBMS website.

Staying safe on your survey

• Please pay attention to signage
  A quick reminder to prioritise safety while surveying. Always follow on-site signs, notices, and access restrictions - even if you're familiar with the area.
  Avoid areas marked as restricted or closed, even if they appear safe. There may be ongoing activities like tree felling, harvesting, construction, or other land management works. If you're unsure, pause your survey and check with the site manager or landowner. Staying safe helps protect both you, site operatives and the wider survey effort. Thank you!
   

• Don’t get ticked off!

  It is tick season so remember the simple measure you can take to avoid being bitten: cover up with long sleeves and trousers, consider using insect repellent, check for ticks after fieldwork and make sure you know what to do if you find one.

A Black Hairstreak surprise – by Fiona Barclay, Transect Surveyor

Monday 2nd June dawned fair. I’d checked the five-day forecast the previous evening, listened to the outlook on Farming Today, and decided that today would be transect day. I bimbled off to Whitestones Twywell Hills and Dales (a UKBMS transect near Kettering, Northants) mid-morning and got myself organised. Marching to the start of the transect, I reflected on what I might see. I wondered whether all the Grizzled and Dingy Skippers might be over, and whether we were entering the “June Gap.” So, I didn’t have terribly high expectations for the walk.

I was just noting the date, time, and weather conditions when I spotted an insect in the grass below knee level. I was sure it would be a Burnet Companion (it seems to be such a good year for these), but when I bent down to check, I got quite a shock—a Black Hairstreak!

This pretty little beast was slightly crumpled, but I managed to get a couple of photos and a short video on my phone. I wracked my brain, almost certain that this species wasn’t known from Twywell. There was plenty of Blackthorn around, and I’d heard from the county recorder, David James, that the species was having an excellent year. The hairstreak didn’t seem fully inflated yet, but as I watched, it took off and flew up into the Blackthorn, disappearing from view. I sent a message to David, including a photo, and continued with my transect.

It wasn’t until later that afternoon that David confirmed it was indeed a new site for Black Hairstreak. I was pleased as punch. It just goes to show that transect walking can throw up the most pleasant surprises.

The Black Hairstreak that Fiona spotted.

Big Butterfly Count
 

Get ready for this year’s Big Butterfly Count! It runs from Friday 18th July to Sunday 10th August.

Get your butterfly counting fix in between your regular surveys with these quick, 15 minute counts. Whether it’s in your garden, a local park, or during a family outing, it’s a great way to enjoy butterflies and even spark an interest among friends and relatives.

Bringing an old transect back to life

To mark the 50th survey season, I decided to revive a transect near me that was one of the original routes set up when the survey began. Craig y Cilau is a stunning limestone reserve first surveyed back in 1976. It was monitored for 12 years, then on and off until 1997…but has not been surveyed since.

In spring, I checked the old route on the UKBMS website and headed out with a map for a recce. Unsurprisingly, nature had done its thing and some parts were now scrubbed over and impassable. So, I had to amend the route to make it a viable transect again.That means it has to be set up as a new route on the UKBMS website to ensure that data stays comparable across years and we can produce reliable population trends. The new route still includes much of the original one, and fingers crossed, will be monitored for many seasons to come.
 

Left – Impassable original transect route - taken in April. Right - Jo surveying the new transect route taken in June.

You can view all UKBMS sites on an interactive map, including dates of first and last surveys and a list of species recorded.

Join us for a special 50th Anniversary celebration!

We’re excited to invite you to a special celebratory conference on Saturday 11th October in Nottingham.

This inspiring day will celebrate five decades of the UKBMS, highlighting the incredible achievements of the scheme and the vital contributions of our amazing volunteers. Together, we’ll celebrate the power of citizen science and the impact your efforts have made.

You’ll hear from leading butterfly experts about how your data is making a real difference, with a range of talks and events throughout the day. The full programme will be announced soon, and you’ll be able to book your free place shortly.

Stay tuned to our social media channels and the UKBMS website for the latest updates—we can’t wait to celebrate with you!

New team members

Over the past few months, we've welcomed several new members to the UKBMS team. Four new Regional Transect Coordinators and two new WCBS Champions have joined us. These volunteers help coordinate surveys in their regions. If one of them covers your area, drop them a message to say Hi!

Regional Transect Coordinators

• Devon: Andrew Blewett
• Lincolnshire: Ian Paterson
• Highlands: Izzy Morgan
• West Midlands: Simon Jones

WCBS Champions

• Northern Ireland: Stephen Craig
• South Wales: Kirsty Mayron

Contact details for all your Regional Coordinators can be found on the UKBMS website. 

Assemble registration

All UKBMS volunteers that survey a transect or WCBS Square must be registered on Assemble, our volunteer portal. If you’re not already, please follow the appropriate link below to register.

Follow us on social media

For regular updates from UKBMS follow us on Bluesky @ukbms.bsky.social or X @UKBMSLive.

You can contact the UKBMS team at:

transect@butterfly-conservation.org
 

survey@butterfly-conservation.org

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Registered Office: Manor Yard, East Lulworth, Wareham, Dorset, BH20 5QP, Tel: 01929 400 209

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