SPECIES UPDATE

THETFORD FOREST OCCUPIES much of the landscape near my home in Norfolk. It is a patchwork of habitats, with the dark quiet stands of dense commercial conifers interspersed with open areas, colonised with grasses, heather and bracken. In early spring, these clearings ring with the songs of Wood Larks, and, in April, their smaller counterparts, Tree Pipits, arrive from their wintering grounds in Africa. A Tree Pipit delivering a parachuting song flight to a still clearing, under a hot June sky is, for me, one of the sounds of the forest. Thetford Forest provides perfect habitat for breeding Tree Pipits, which need open areas dotted with tall perches, such as heathland with trees, or young plantations. However, the distribution maps in the 2007-11 Bird Atlas, show that while there are good numbers of Tree Pipits in Thetford Forest, this Norfolk population is becoming increasingly isolated. Most Tree Pipits are found in woodlands in Scotland, Wales and northern England, with other populations in scrubby downland in southern England. However, they are now absent from much of eastern and central England. BTO monitoring data show that Tree Pipits declined dramatically between the late 80s and the mid-90s, coinciding with their loss from central and south eastern England, particularly woodland and common land. The Breeding Bird Survey monitoring scheme started in 1994, and these annual counts by volunteer birdwatchers show that Tree Pipits have continued to decline, moving from the green list to the amber list in 2002, and then to the red list in 2009, indicating the greatest conservation concern. However, the results from these survey sites vary markedly across the country, and the national decline is driven by the extreme losses in England, while Tree Pipit numbers in Scotland have actually more than doubled over the past 20 years. There is plenty of evidence available linking this decline of Tree Pipits in England with the changing structure of our forests. Historically, wood was regularly harvested from many of our lowland woodlands through coppicing, and this management kept the structure open, perfect for Tree Pipits. However, by the middle of the 20th RISE AND FALL The song of the Tree Pipit is heard less often in England in recent years, but more often in Scotland The BTO runs volunteer surveys to monitor and explain changes in bird populations. To find out more about the Waterways Breeding Bird Survey visit Century coppicing was in rapid decline, forest canopies closed over, and our woodlands became unsuitable. In Scotland, the increase of commercial conifer forestry may have benefited this species, though only where the forests are regularly harvested to produce the clearfell areas and young plantations that they prefer. Research on targeted management has shown that providing large blocks of their favoured habitats, and retaining some mature trees as song posts, can successfully increase Tree Pipit numbers in commercial forests. While Tree Pipits can be found in our woodlands during the spring and summer, by September they are on the move, on their way to the humid forests south of the Sahara. There are clearly significant issues with the habitat in, or on the way to, these areas, since all of our humid-zone migrants are showing similar declines. We don’t know exactly where British Tree Pipits winter. However, if we want to know the full story about what is causing our bird populations to decline, it’s clear that the questions about what is happening beyond our shores are the next big ones to answer.

Kate Risely is the British Trust for Ornithology’s Garden Birdwatch Organiser

Most Tree Pipits are found in woodlands in Scotland, Wales and northern England, with other populations in scrubby downland in southern England