One of our specialist heathland birds, the Dartford warbler, has suffered a dramatic population decline at some of its most important breeding sites in south east England according to the latest report from the Rare Breeding Birds Panel (RBBP).
The report paints a bleak picture for the Dartford warbler, which has declined substantially in the last few years, because of the harsh winters leading up to 2010.
The RSPB has been working to help the Dartford warbler since the harsh winter of 1962/1963, and extensive habitat management to regenerate and improve heathland had enabled a vital recovery of the Dartford warbler in England. In 2004 there were almost 1000 pairs in the Thames Basin and Wealden Heaths.
However the impacts of further harsh winters have shown signs of knocking the population back at some key sites.
Sadly, in 2010, just 50 pairs of Dartford warblers were reported across areas of Berkshire, Hampshire, Surrey and Sussex.
Dave Burges, conservation officer for the RSPB in the South East said: “It is believed that warmer summers and, until recently, milder winters had allowed Dartford warblers to not only increase their numbers in the south east, but to also spread further north in England. But the recent run of harsh winters appear to be taking their toll on this bird.”
Heathland is both a cultural landscape and a scarce but hugely important wildlife habitat. It once covered vast areas of southern England but we have lost 75% of this precious resource and what’s left is highly fragmented.
Together, the Thames Basin Heaths, the Wealden Heaths and Ashdown Forest, form a vital complex of heathlands in southern England that support a whole range of wildlife including threatened UK breeding bird populations.
Heathland continues to face significant threats, despite intensive conservation action over the last 20 or more years.
However, there is significant potential to restore heathland where it has been lost relatively recently, making sites bigger and reconnecting them, which makes dependent wildlife more resilient to the pressures of a changing environment.
The report also found that, in contrast to the declines of the Dartford warbler, other birds are faring better.
The firecrest – one of the UK’s smallest birds – is increasingly nesting in Britain, from further south in Europe. It is commonly found in Surrey, Sussex, parts of Hampshire and there are growing reports from across Kent.
Firecrests first colonised the UK half a century ago, when the first nest was found in Hampshire in 1962. Since then the population has risen, and the latest report from the RBBP suggests there may be over 1000 pairs nesting in Britain, primarily in southern England.
Mark Holling, secretary of the RBBP, said: “In the last 50 years there have been a number of species which have nested for the first time in Britain. Some, like the purple heron, have only nested once but others, like the little egret and firecrest, have gone to become established and relatively widespread nesting birds.
“These shifts shown by some nesting birds fit the pattern of climate change with species moving from further south in Europe to colonise the UK.”
Dave Burges added: “Perhaps the firecrest’s success in Britain shouldn’t come as a surprise. The warmer summers we’ve seen in recent decades favour this bird, and during the winter it leaves its nesting sites to winter along the coast of South West England or on Continental Europe, so avoiding the worst of our winter weather.
“Sadly, the Dartford warbler is a casualty of the combined double whammy of weather and climate: a changing climate in the south of its range is affecting it, with rapid declines in its Spanish and Portuguese heartlands. While in the north of its range, where the summer climate is improving, it is being badly affected by harsh wintry weather.”