21 September 2005
Image: Andy Hay
The RSPB is developing a package of measures to ensure that tree sparrow populations are maintained within their current range across the UK.
Tree sparrows were once widespread and familiar in the countryside, but have now vanished from many areas. They are quite similar to the closely-related house sparrow, but ‘neater’ in appearance and, in the UK, less closely associated with people.
Tree sparrows have undergone a dramatic decline in population and range in the UK with a 95% decline between 1970 and 1998. These birds are now patchily distributed, being rare in much of Wales, parts of the north west and south east England, and largely absent from many of the southern counties of England, and north western counties of Scotland. In some areas, there are still colonies in localised areas, but with large gaps elsewhere.
The security of these colonies varies across the UK, with some doing well and in some cases even increasing, whilst others are still in danger of being lost.
Image: The RSPB
The huge decline in tree sparrow numbers is probably the result of agricultural intensification and specialisation, particularly the increased use of herbicides and a trend towards autumn-sown crops (at the expense of spring-sown crops that produce stubble fields over winter).
The change from mixed to specialised farming and the increased use of insecticides will have reduced the amount of insect food available for nestlings.
Research by the RSPB at Rutland Water has shown that a good availability of invertebrate food for chicks close to the breeding sites is crucial. The breeding season is very long (April to mid-August) so a diversity of good quality habitat is needed to ensure continuity of supply.
At Rutland Water, this research by the RSPB and others also points to a lack of seed food, particularly in winter, as being a key factor, but this is still unclear. Nestboxes are readily used, and, together with provision of good feeding areas, may help colonies to survive.
It is too early to say what the future holds for tree sparrows as the work is still in its early stages. A package of measures to improve habitat and provide nest-sites is being promoted to farmers and landowners, and support for these is now available through a number of agri-environment schemes. The RSPB is trialling and monitoring the effectiveness of a number of these options that could help tree sparrow populations to recover.
The RSPB is also involved in recovery projects at a number of tree sparrow ‘hotspots’ in parts of Wessex, north-west England and Lothian/Borders, with the aim of maintaining these important populations.