The Butterflies of Billingshurst
By Chloe Harrison
Community Support Officer, Wilder Horsham District
With an unseasonably wet and cold spring, the emergence of our UK butterflies this year was delayed. But a few weeks ago, when the warmer, sunnier weather has finally arrived, we hastily organised a walk with local nature and environment group Billigreen to see what butterflies Billingshurst has to show off. It turns out – there’s plenty to shout about!
Watching Purple Hairstreaks on the 'Purple Emperor Walkway'
Just as the sun came out, we arrived at our first stop on the tour – the newly crowned ‘purple emperor walkway’. The walkway winds up and around through an understory of brambles opening up in front of a large, mature oak, as if it was a purpose-built butterfly viewpoint. Our necks certainly appreciated not having to look up and strain as much as from ground-level. While we did not see any purple emperors this time around, they had been recorded in this place before, and were very likely watching us from their invisible perch in the oak above. An uncommon sight restricted to just southern and central England, it is a wonderful species to have recorded in Billingshurst. We did however spot the purple hairstreak by its jittery flight and silvery underwings, which every oak tree can boast. They lay their eggs on the tree, and come early evening countless individuals will light up the sky around their oak in flight.
On we walked to a field of meadow grass and wildflowers, the grass providing the perfect food plant for caterpillars. Here we spotted many a meadow brown, the bread-and-butter-butterfly of meadows, and the not-too dissimilar gatekeeper. Originally thought to be the same species, we also caught the two near identical skipper butterflies that can only be distinguished by looking at the colour of underneath of their antennae. The small skipper under-antennae is orange, the Essex skipper’s black.
But it was the brilliant edge habitat of blackthorn between the meadow and trees that held our attention most, as it was the perfect habitat to see a brown hairstreak. As a UK BAP priority species only found locally distributed in southern Britain, Billingshurst falls right in the middle of its last strongholds and so should be one of the best places to see them. Laying their white eggs of blackthorn shoots, it is wonderful to watch them tasting the leaves with their feet and displaying their orange underside markings.
Perfect Brown Hairstreak habitat in Billingshurst
...and a perfect Brown Hairstreak (photo by Bob Eade)
Our last stop on the walk was a visit to the newly crowned ‘White letter hairstreak lane’, where a bunch of mature elms sitting just along the roadside provide the perfect opportunity to spot the increasingly rare white letter hairstreak butterfly. Relying on elms as their foodplant, the devastation of elms by Dutch Elm disease has seen them in decline since the 1970s, but they are hanging on in places such as Billingshurst where their habitat remains.
Looking up for White-letter Hairstreaks
Even without their rare status in the mix, they can be a tricky spot. Combine their small size and preference to fly around the very tops of trees, they are difficult to see unless they fly, and even then can easily look like a bee in flight. We were not lucky enough to spot them this time round, but a visit to the same spot just two weeks before had proved successful. If you have a pair of binoculars on you, scan for a shark-fin like wing shape with orange edges and a white streak when it lands. But your best bet for an ID is to keep a look out for its erratic, spiralling flight typical of hairstreaks.
Thank you to Billigreen for having us. With several nationally scarce or isolated species finding their home and preferred habitat in Billinghurst, it is an exciting home for many butterflies and a great place to spot the likes of the purple emperor, brown hairstreak and white-letter hairstreak.