The British public is being urged to keep an eye out for the striking Jersey Tiger moths, which are experiencing a population boom. Butterfly Conservation, the wildlife charity, said these day-flying moths seemed to be thriving as people participate in the organisation’s annual butterfly count.
This initiative, spanning three weeks each summer and currently active until August 10, invites people to spend 15 minutes noting down the butterflies they spot in their gardens, local parks, or rural areas. This year, the charity is calling on the nation to join what it calls a “nationwide rescue mission” to aid the struggling butterfly species of the UK.
At the halfway stage of the count, Butterfly Conservation has reported sightings of 5,300 Jersey Tiger moths, a significant increase from the total of 3,496 recorded during last summer’s entire count. This represents a 78% surge since 2024 on a per-county average basis, with the rise being credited to the warm, dry weather conditions that have likely enabled the species to flourish and colonise regions of the UK where they are not typically found.
These moths are easily identified by their distinctive black and white tiger-striped forewings and the vivid red-orange or yellow hindwings, which feature prominent black spots. According to Butterfly Conservation, just ten years ago, the Jersey Tiger was predominantly confined to the Channel Islands, the southern coast of England, London, and south-east Wales.
Jersey Tiger moths, once a rare sight, are now increasingly being seen across southern England and are spreading into East Anglia and the Midlands. The charity reports sightings this year in Cardiff, Birmingham, Cambridgeshire, and Essex, despite last year’s record low numbers due to a wet spring and cool summer.
However, conservationists caution that these come after long-term declines in the UK. More than 80% of butterfly species have seen a decline since the 1970s, with habitat damage, climate change, and pesticides cited as major factors. Butterfly Conservation has noted that while the striking appearance of Jersey Tiger moths has captured public interest, their presence in new areas also highlights the impact of climate change.
Dr Richard Fox, Butterfly Conservation’s head of science, said: “Butterfly and moth numbers fluctuate naturally each year depending on the weather, and this summer’s warm, sunny conditions have created a much more favourable environment than last year’s cool, wet season, which saw numbers recorded during Big Butterfly Count plunge to record lows. It’s certainly uplifting to see more butterflies and moths this summer, but one good year can’t undo the long-term decline many species are facing.”
Dr Fox has observed that during favourable years, population peaks of certain species have become less pronounced over the last five years, with numbers plummeting even more in adverse years. He pointed out that the rise in Jersey Tiger moth sightings is indicative of the way climate change “is reshaping the distribution of wildlife”.
“While it’s a delight to spot such a vibrant moth in gardens, parks and green spaces, it’s also a reminder of how rising temperatures are altering our natural environment,” he said. Dr Fox emphasised the importance of the Big Butterfly Count: “This is why the Big Butterfly Count matters. The more people who take part, the more we can learn about how species are adapting, or struggling, in the face of climate change and extreme weather.”
The data gathered by citizen scientists during the Big Butterfly Count is crucial for shaping national conservation policies, ensuring the protection of butterflies, moths, and the broader ecosystems they inhabit.