Wooded Fields Good For Birds

Summary from Bird Study
22nd September 1996

A modern crop being grown in Britain on set-aside and other land is 'Short Rotation Coppice'. With this, trees are grown from root stocks planted one metre apart and harvested by cutting to the ground every three or four years for use as fuel. The trees used are mostly willow or poplar.

Rufus Sage and Peter Robertson, reporting in the latest issue of Bird Study (43, 201-213) have proved that willow fields, the ones most often planted, provide homes for quite a wide variety of birds. The top species, found in more than ten of the 49 willow plots surveyed, were: Blackbird (25 plots), Sedge Warbler (13), Reed Bunting (13), Chaffinch (13), Wren (13), Robin (12) and Sedge Warbler (11). These are common species but not likely to be found in such numbers in normal farm crops. However, in traditional coppice, they represent the range of species normally found in the first 10 or 12 years. Even open nesting species, like the Skylark, which would be found in open crops are able to exploit the coppice in the summer after winter cutting.

Poplar SRC was not as good for the birds. Only Blackbird (6) and Great Tit (3) were found on more than two of the 17 plots surveyed. Willows are very good for insect abundance and this may be the reason for this difference. Happily the preference in Britain is for willow rather than poplars as they are more tolerant of poorer soils. there was a suggestion, from the habitat parameters gathered, that warblers were more numerous in plots which were weedy.

Certainly it is well known that in old-established osier beds Reed and Marsh Warbler prefer those with nettles. The rapid growth and harvesting of these plots means that the habitat for the species which use them is renewed very quickly. There are plans to grow 3,000 hectares of SRC in Britain as the response to the Non- Fossil Fuel Obligation. This may be good for the birds and even encourage the scarce Grasshopper and very rare Marsh Warblers to breed in areas where they are now absent.