World Swallowtail Day 2023

World Swallowtail Day 2023

Oscar takes a trip to Hickling to celebrate World Swallowtail Day.

The swallowtail is a beautiful butterfly and can only be found at a few locations in the UK, but one of the best is NWT’s Hickling Broad. Every year these iconic butterflies are celebrated on World Swallowtail Day and large numbers of people flock to Norfolk to get a view of the swallowtails. The date varies from year to year depending on when swallowtails have emerged, so usually mid-June. I journeyed up to take a look at my favourite butterfly on the 11th of June, at the heart of the festivities on this special day.

Hickling Broad is unrivalled for Norfolk wildlife, with many landmark species found here. These include the Norfolk hawker dragonfly, swallowtail and bearded reedling. With high hopes, I doused myself in sun cream before stepping out into the boiling June heat. Given the recent cold spell, a couple of hot days could spur the swallowtails’ emergence...

I decided that first I would head down to the visitors centre pond to see if there were any dragonflies about. I found many blue damselflies or bluets, but then something caught my eye. A black and yellow butterfly circled for a minute, then raced off over the lawns. The first fleeting glimpse of a swallowtail on World Swallowtail Day! 

We met a man at the visitor centre who had made carvings of swallowtails using a chainsaw and a log, which I thought was rather impressive! They were intricately painted, and were also very well whittled. So, having asked where to look for swallowtails, we set off to catch our boat.

At Hickling, a man displays his carvings of swallowtail butterflies made out of bits of log.

On the way, we passed a magnitude of wildlife; the highlight being an otter we found rustling in the reeds by the main broad. A Norfolk hawker patrolled one of the paths, looking out for an insect meal. Norfolk hawkers are easily identified by their bulging green eyes, clear wings and brown body. They’re rare and endangered among British dragonflies, so it was a privilege to see them here.

We arrived in good time at the boat launch which was due to take me and my mum (as well as other avid naturalists) around the reserve. I discussed, as the boat set off, the swallowtails with the captain, Jim. I asked if climate change was going to affect swallowtail numbers and he told me that the biggest concern is water salinity; with rising sea levels and Hickling’s proximity to the coast, the marsh could be flooded with saltwater, altering the swallowtails' habitat. On a positive note, Jim was not concerned about any imminent impacts on swallowtails - he explained to us all that numbers have always fluctuated.

Dragonflies were abundant on the day, such as Norfolk hawkers, hairy dragonflies, black-tailed skimmers, four-spotted chasers and a resplendent emperor. Emperors are Britain’s largest dragonfly, with a unique bright blue abdomen and apple-green thorax.

Common and little terns performed awesome aerobatics over the broad, searching for fish. Every now and then one would take a magnificent plunge-dive into the water, leaving a large splash of bubbles in its wake. There was the occasional view of a swallowtail, but they just didn’t seem to want to sit down, fluttering through the dykes and ditches.

Oscar is looking over the broad with his binoculars at Hickling

After departing from the boat, however, we spotted a throng of visitors, their cameras trained on the reeds. We went over to the crowd to find the source of the commotion. It was a magnificent swallowtail basking on a reed not 3 metres away! This was what we had come for. Yellow wings patterned with black, a bright red and sky-blue ‘eye’ and a pair of fake “tails” which give it its name. My best sighting of one yet this season. We took some photographs and enjoyed some excellent views of this incredible butterfly.

The species of swallowtail found in the Norfolk Broads is Papilio machaeon britannicus, found nowhere else in the whole world. They're ristricted to the Broads where milk parsley grows, which is the caterpillar's sole food plant.

By the time we returned to the visitor centre, it was packed with people, including Dr Tim Willey. He was a sculptor and volunteer for NWT, making huge insect statues from reeds. There were many volunteers around, ready to help and inform visitors about Hickling and its nature. It is incredible that so many people, on their own time, are devoted to conserving and reviving Norfolk’s wildlife.

World Swallowtail Day was jam-packed with all sorts of wildlife: from otters to terns; from dragonflies to butterflies. One thing is for certain, though: I will definitely be coming back!