Dartford warblers make impressive comeback as they reach highest ever numbers on RSPB nature reserves

Becca Smith

Monday 2 May 2022

The highest ever total number of Dartford warblers (183 pairs) have been found on RSPB nature reserves, the recently launched RSPB’s Ecology Report has revealed, bouncing back from near extinction in the 1960s.

  • The amber listed bird previously suffered from a population crash in the 1960s, leaving just a few pairs in Dorset and the species on the brink of extinction here in the UK.
  • Thanks to their comeback they can now be spotted on heathland sites including RSPB Minsmere in Suffolk and RSPB Arne in Dorset.

Dartford warblers have made an impressive comeback, the recently launched RSPB Ecology Report has revealed, as the highest ever number of the birds found on RSPB nature reserves has been recorded.

The lowland heathland dwelling bird, which relies on the habitat’s dense gorse, is particularly sensitive to cold weather and has previously suffered as a result of harsh winters. Dwindling down to just a handful of pairs in Dorset during a population crash in the 1960s, Dartford warblers were at real risk of extinction from the UK just 60 years ago. However, thanks to concerted conservation efforts to create and restore heathland, and a series of milder winters, the bird fared well on the RSPB’s nature reserves in 2021, with numbers totalling 183 pairs.

Notable numbers of the birds were found at RSPB Minsmere on the Suffolk coast, which celebrated its 75th anniversary as an RSPB nature reserve last week. Increasing from 2019’s survey results, which found 23 pairs on the nature reserve, 2021’s surveys counted an impressive 37 pairs of Dartford warblers calling RSPB Minsmere home.

Mel Kemp, the warden at RSPB Minsmere, oversaw the heathland restoration at the site, including across 17 hectares of ex-coniferous plantation, and is delighted with the outcome: “We have seen a steady increase in the number of Dartford warblers, alongside other species relying on heathland habitats such as nightjar. All the hard work of restoring this habitat has really paid off.”

Despite their gradually increasing numbers, Dartford warblers are still considered an amber listed species in terms of conservation status. Thankfully, the RSPB’s lowland heathland nature reserves provide the perfect conditions for these long-tailed warblers, with the male slate grey and chestnut birds often spotted singing from the tops of gorse bushes in April and May sunshine, hoping to attract a mate.

As well as being the perfect singing platform, gorse is a tightly packed, spikey shrub that provides a safe nesting place and hunting ground for the bird which specialises in picking spiders and caterpillars from their hiding places.

Talking about the species and its growth across the UK, Mel continued: “Dartford Warblers are a fantastic bird to see on our nature reserves and beyond, and we are fortunate enough to have growing numbers of them here in the UK.

As climate change puts pressure on the areas Dartford warblers can call home across the globe, we must ready ourselves to become more responsible for safeguarding the future of this species as a higher percentage of the global population flock to UK heathlands.”

Heathland is one of the UK’s most threatened homes for nature. While supporting a range of wildlife from birds and mammals to insects, reptiles and amphibians, here in the UK 80% of our heathland has been lost since the 1800s due to land-use change.

Rare birds like woodlark and nightjar also nest on heathland sites, which are often popular places to walk, cycle, horse ride and picnic too. By keeping yourself and your animals to footpaths, you can help to keep chicks safe. Fire risk can also be very high on heathlands, so pack a picnic rather than a BBQ and take any litter home.

Mel continues: “Increased responsibility for the Dartford warbler population means we need to continue to restore, manage and protect the heathland we have left here in the UK to best ensure the future of not just this species, but many others too.

With 13% of species that depend on our heathlands and grasslands now at risk of being lost from the UK, our conservation and monitoring work, as captured in the RSPB Ecology Report, has never been more important in the face of the Nature and Climate Emergency.”

Dartford warblers can be found on RSPB nature reserves including:
RSPB Arne, Dorset
RSPB Aylesbeare Common, Devon
RSPB Broadwater Warren, Kent
RSPB Farnham Heath, Surrey (which celebrates its 20th Anniversary this year)
RSPB Hazeley Heath, Hampshire (which celebrates its 10th Anniversary this year)
RSPB Minsmere, Suffolk (which celebrated its 75th Anniversary on 25 April this year)


Image: a Dartford warbler perches on heathland at RSPB Arne, Dorset. Credit: Ben Hall, rspb-images.com

Tagged with: Topic: Birds Topic: Conservation Topic: Reserves Topic: Wildlife