A Focus On Nature

Advent Calendar

Conserving the High Brown Fritillary at Exmoor National Park

I think it’s safe to say that winter is most certainly here, and on these cooler, crisper, and increasingly shorter days, I look back fondly at the time I spent helping with local conservation efforts back in the middle of June. As part of my Gold DofE Residential, I chose to help out with butterfly habitat management at the expansive and diverse Holnicote Estate in Exmoor National Park, alongside the National Trust.

I’d just finished the second year of university, and after a scenic train journey from Falmouth to Barnstaple, I met with the volunteer leader for the trip, Carol, and her obedient canine companion, (a German Shepherd / Border Collie cross). We soon headed onwards from the train station in the minibus, and collected additional volunteers from a variety of backgrounds, including as far as Texas! I hadn’t been near to Exmoor in almost a decade, since a memorable family holiday to Ilfracombe in 2008, and so I was amazed to rediscover the beautiful green expanses and steepness of the region, as our minibus groaned up the dramatic 1:4 cliff-top roads to the quaint bunkhouse we’d be staying at in the village of Countisbury.

In total our volunteer team was composed of 10 people, and of course, Buster. Once we’d introduced ourselves, and a had a tour of the bunkhouse, we were briefed on the conservation activities planned for the week. We were also informed of the fact the weather forecast predicted bright sunshine, and 25-30°C temperatures all week; absolutely perfect for us and the butterflies, which are energised by such conditions! That evening, and indeed every night thereafter, we ate delicious homemade meals, with full courses, and portions that made it feel like Christmas Day every day. It goes without saying I slept well that night, and felt ready for the work ahead.

The next morning, our volunteer team headed out to the National Trust Centre for the Holnicote Estate, and met with the local site rangers and members of Butterfly Conservation. They explained to us that Exmoor provides a stronghold for more than 30 species of butterflies, including the country’s rarest, most-threatened fritillary: the High Brown fritillary (Argynnis adippe). This once common species, has experienced alarming declines of -79% since the 1970’s – as a result of habitat reduction and fragmentation, so we’d be doing our bit to reverse the trend and monitor the population numbers. The trickiest part however, was identifying them, as the High Brown Fritillary appears very similar to the commoner Dark Green Fritillary – both present in the area; and both hyper in the high temperatures, rarely settling for more than a split second! We were fortunate enough to have Matthew Oates with us, a seasoned ranger, who could actually distinguish the two during flight, with astonishing accuracy. Meanwhile, I could hardly even get a close-up picture of one!

Our primary duties were to create ‘runnels’ (pathways) through the thick bracken slopes using either bashing or squashing equipment – the latter of which, I became pretty efficient at, if I do say so myself! We also made sure to alert the rangers of any potential High Brown Fritillaries, which were then counted on-the-wing, or carefully captured using a butterfly net. The process of creating runnels may sound destructive, but in fact, it greatly aids the low-flying species, enabling the females to easily locate suitable egg-laying sites. It’s a type of conservation that has instant results, and indeed, there were many occasions where I looked behind to see High Brown Fritillaries following the runnels I’d created, which was greatly rewarding.

On occasions, I found myself scrambling down very steep slopes, roasting in the heat-trap effect of the undergrowth, and fighting through bracken and brambles up to 7 feet tall, reminiscent of The Day of the Triffids, but the hands-on experience taught me a lot. Throughout the week, we visited several picturesque sites across Exmoor, and I got to know many great likeminded people. Overall, I’d highly recommend doing a working-holiday with the National Trust, or any local conservation, if the opportunity arises, as it is a week I’ll always fondly remember.

Adam is a third-year geographer at the University of Exeter Penryn Campus, living in the inspirational county of Cornwall. He enjoys cycling, exploring new places and witnessing the wildlife of the UK – with a keen interest in bird and butterfly species. He has volunteered with the National Trust and the RSPB in recent summers.