The Dartford warbler may be an elusive Dorset resident, but they’re not as rare as some believe, says conservation officer Hamish Murray
One of the pleasures of a walk across the Dorset heathland is hearing the hurried chatter of a Dartford warbler, usually coming from the depths of a gorse bush. Dartfords also have a churring alarm call, which to my ears sounds rather like a soft sneeze.
Although most vocal in the spring, Dartford warblers can be heard singing sporadically throughout the year.
Most warblers are migratory birds but Dartfords are resolutely sedentary, rarely moving more than a few miles from their native heath. They generally manage to survive the British winter on a diet consisting largely of spiders and small insects. However, Dartford warblers are susceptible if there are prolonged spells of cold weather and the population can be significantly reduced by a severe winter.
Dartford warblers are more often heard than seen, but given a reasonable view they are fairly easy birds to identify. The overall impression is of a small, dark bird with a fine bill and a long tail that is often cocked. Closer views will reveal the subtle grey and vinous tones of the plumage and the red eye-ring. The males tend to be more colourful than the females and have distinctive white spots on the throat.
In Britain, Dartford warblers are more or less confined to the heaths of southern England but, in the right habitat, they are certainly not as rare as some books suggest.
Seeing a Dartford warbler is still largely a matter of luck, however. I remember leading a guided walk for a birdwatching group a few years ago, with the main target of seeing a Dartford warbler. We trudged round most of the best-known habitats in Purbeck, and had not a sight or sound of our elusive quarry.
Eventually I had to admit defeat – I apologised and bade farewell to the group as they all piled back onto their coach. Naturally, just as they disappeared down the road, I heard a familiar sound behind me and turned to see a wonderful view of a male Dartford warbler, singing its heart out on top of a nearby gorse bush!