Glowworms Return to Nosterfield After a Century-Long Absence

Glowworms once illuminated the grasslands of Nosterfield nature reserve in North Yorkshire, celebrated in 1909 by writer Edmund Bogg and poet Samuel Taylor Coleridge. Quarrying and intensive farming eliminated the rough, varied grassland they require, leading to their disappearance for more than 100 years. Since 1997 the Lower Ure Conservation Trust has acquired and restored nearly 600 acres of former quarry, creating species-rich wetland and magnesian-limestone grassland that now supports bitterns, marsh harriers and, finally, glowworms again.

The Guardian

Independent ecologist Pete Cooper obtained a small, authorised sample of glowworms from a donor site, bred them in a garden shed in Bristol, and reared hundreds of snail-eating larvae. In 2024 roughly 480 larvae were released at Nosterfield in partnership with the Lower Ure Conservation Trust. Because glowworms need two years to reach adulthood, volunteers counted up to 12 glowing females across successive weeks this summer, confirming that the site can support the full life cycle. Cooper has since bred an additional 1,900 larvae for release later in the year, and fundraising events have upgraded breeding facilities at Westbury Wildlife Park Foundation.

Glowworms Return To North Yorkshire After Garden-Shed Breeding Push

Simon Warwick, director of the conservation trust, highlighted the “raw passion and enthusiasm” of Cooper and the 80 volunteers who refined habitat management and monitored the glowworms. Both officials emphasized that a self-sustaining population may not be confirmed until 2030, when the offspring of this year’s wild adults are expected to mature.

The Guardian

• “It’s a really great first indicator of initial success,” — Pete Cooper

The Guardian

• “We are very fortunate to have a lot of really knowledgable volunteers alongside our brilliant staff who are managing the land that allows the glowworms to re-establish itself in this landscape after an absence of more than 100 years,” — Simon Warwick, the director of the conservation trust

The Guardian

• “It will be wonderful to see this project grow bigger than me,” — Pete Cooper

The Guardian

The trust intends to release the newly bred 1,900 larvae later this year and continue habitat improvements. Ongoing data collection by the UK glowworm survey will guide further translocations, while the breeding programme aims to expand beyond Nosterfield, offering a model for other conservation groups seeking to re-establish this rare invertebrate.

The Guardian