Return of the Dartford warbler

ONE of Britain’s rarest birds, the dimunitive Dartford warbler, which was threatened with extinction, with just a handful of pairs in Dorset in the 1960s, has made an impressive come-back, with 183 pairs recorded on RSPB reserves in 2021.

The recently launched RSPB Ecology Report records this good news, which is attributed to concerted conservation efforts to create and restore heathland, and a series of milder winters. 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.

Notable numbers were found at RSPB Minsmere on the Suffolk coast, which has just celebrated its 75th anniversary as an RSPB nature reserve. The 2021 survey recorded 37 pairs, a substantial increase on the 2019 figure of 23 pairs.

Despite the welcome increase, Dartford warblers are still considered an amber listed species in terms of conservation status. Thankfully, the RSPB’s lowland heathland nature reserves, such as Arne, on the edge of Poole Harbour, 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.

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 per cent of heathland has been lost since the 1800s due to land-use change.

Pictured: A Dartford warbler perches on heathland at RSPB Arne. Photograph by Ben Hall, rspb-images.com