RSPB records 264 Dartford Warbler pairs across 14 sites
RSPB reserves recorded a record 264 dartford warbler pairs across 14 sites in southern England in 2025, the highest total ever counted on the charity’s nature reserves. At RSPB Arne in Dorset, Senior Site Manager Peter Robertson said the summer chorus showed years of restoration work paying off.
Arne Records 97 Pairs
Arne posted 97 pairs, a new site record, while RSPB Minsmere recorded 41 pairs. RSPB Aylesbeare counted 25 pairs, Farnham Heath 23, North Warren 17 and Broadwater Warren 15.
Robertson said, “Staff and volunteers have helped connect and enlarge fragmented patches of precious heathland to give wildlife, such as the distinctive Dartford Warbler, the space to thrive” and “Being able to hear those calls is the perfect reminder that the hard work is paying off.”
Heathland Birds Survey
The 2025 Heathland Birds Survey put the national population at around 4,100 territories, up from 3,200 territories in the last full survey in 2006. The survey was organised by the RSPB, British Trust for Ornithology and Natural England, with more than 1,200 volunteers contributing data.
Dr Greg Conway, Senior Research Ecologist at the BTO, said “the results showed how habitat management and the creation of suitable sites could continue to support the species’ recovery and range expansion in future years.”
Arne Heathland Work
The count also sits against a longer decline: severe winter weather in the early 1960s reduced dartford warblers in Dorset to only a handful of pairs. Lowland heathland, one of Britain’s rarest and most threatened habitats, has lost around 80% of its area since the 1800s through forestry planting, farming and development.
At Arne, another 15 hectares of farmland were being converted back into heathland, extending the habitat that supports nesting cover, shelter and feeding for the species. Farnham Heath and Broadwater Warren were largely conifer plantations just two decades ago, and both are now among the sites adding to the reserve total.
