Tree Sparrow Passer montanus

Tree Sparrows are similar to the more widely recognised House Sparrows but are smaller and more active. They have a chestnut brown head, white cheeks and a contrasting black cheek-spot. They also have a black bib and an unmarked pale grey underside. Their back is dull brown, the wings dull chestnut brown with two white wing bars and the rump is yellowish with a square-tipped tail. The male and female of this species are identical. The Tree Sparrow's call consists of varied chirps and cheeps generally similar to the House Sparrow but shorter and higher pitched.

Tree Sparrows are birds of lowland farmland but will also inhabit large gardens, especially where nest boxes are provided. They prefer mature trees in open country, on the edge of woods or in hedges. Tree Sparrows usually nest in holes (including nest boxes) but may build a nest in thick, large Hawthorn hedges if no holes are available. They form mixed flocks with other farmland species during the autumn and winter, moving around to make best use of available food resources. They feed mainly on the seeds of grasses, cultivated cereals and arable weeds such as Nettles, Knotgrass, Buttercup, Poppy and Chickweed. The breeding season lasts from mid April to early August and two or three clutches, containing between two and seven eggs are produced. The chicks are fed almost entirely on insects such as Aphids, Beetles and Grasshoppers.

Current Status

Tree Sparrows are patchily distributed on farmland across Britain and Ireland. They are more scarce in the uplands and the far north and west. The main populations are now found across the Midlands, southern and eastern England. They are almost absent from the south west, Wales and the north west. The Tree Sparrow is still common and widespread across mainland Europe.

This once common farmland bird has suffered a serious decline in breeding numbers over the last 25 years. The Common Bird Census (CBC) indicates a decline of 95% in numbers in Britain between 1970 and 1998. This is the largest decline of any common species during this period. The Tree Sparrow also decreased in range by 20% over the same period. The most recent population estimate (1988-91) suggests that there are about 110,000 breeding pairs. Their numbers are known to fluctuate unexpectedly (apparently unrelated to climate or weather effects) but the steady decline over the last 50 years coincides with agricultural intensification and specialisation. The Tree Sparrow is on the RSPB Red List of 'Birds of Conservation Concern' and also appears on the UK Biodiversity Steering Group (UKBSG) 'Middle List of Globally Threatened/Declining Species'.

Records show that Tree Sparrows were once very common within Hull but the national decline became evident in the area by the 1980's. Since 1995 the only Tree Sparrows known to be breeding in Hull were all west of the River Hull. About 15 pairs used to breed in the fields around Priory Road just outside the city boundary, but owned by Hull City Council and managed under Countryside Stewardship. However, this area has not held Tree Sparrows since 2000. Wintering flocks were also recorded in the same area, in addition to flocks at North Bransholme, Sutton and Bransholme Sewage Works.

Current Factors Affecting Tree Sparrows

• Little is known about the factors affecting numbers of Tree Sparrows, but their recent decline has occurred at the same time as decreases in the numbers and/or ranges of other farmland seed-eating birds. It is therefore likely that their decline is due to changing agricultural practices. These changes include the increased use of pesticides and herbicides, which has reduced the availability of insects. The change from spring-sown to autumn-sown crops has severely reduced the areas of winter stubble feeding grounds. The more intensive management of grassland and the general reduction in habitat diversity on farmland due to loss of mixed farming and increased specialisation may also have affected Tree Sparrows.
  
  
• Removal of hedgerows on farmland and lack of management of existing hedgerows has reduced the availability of nesting habitat for Tree Sparrows.
  
  
• The loss of Elm trees in the late 1970s and 1980s, due to Dutch Elm disease reduced the availability of nest holes.
  
  
• Habitat loss due to urban development may be particularly important in the decline of Tree Sparrows within Hull.

Current Action

Legal Status

The Tree Sparrow is protected under the Wildlife and Countryside Act (1981). It is illegal intentionally to kill, injure or take any wild bird, intentionally take, damage or destroy the nest of any wild bird while it is in use or being built or intentionally take or destroy the egg of any wild bird. The Tree Sparrow also receives protection under the EC Birds Directive (1979).

Management, Research and Guidance

The UKBSG has produced a national Species Action Plan for the Tree Sparrow. The plan aims to reverse the decline in numbers of the Tree Sparrow by the year 2003, then see a sustained recovery so that numbers are 50% higher than 1996 and a measurable increase in range is achieved by 2008.

Nationally little direct conservation work for the Tree Sparrow has been carried out although nest box schemes have been implemented in a number of areas. The RSPB has recently purchased a 180-hectare farm in Cambridgeshire, which will be used to investigate and develop new wildlife-friendly farming methods to benefit bird species such as the Tree Sparrow.

There is currently no management specifically for Tree Sparrows within Hull, although they could potentially benefit from the Country Stewardship Scheme at Priory Meadows and Snuff Mill Fields. Several individuals and groups within Hull record sightings of birds and these are important for identifying changes in Tree Sparrow numbers and distribution.

Action Plan Aims

1. To identify Tree Sparrow breeding colonies.
2. To monitor Tree Sparrow breeding colonies to detect any threats or population changes.
3. To increase the length of hedgerow within Hull.
4. To enhance existing hedgerows.
5. To improve hedgerow management.
6. To improve links between woodland sites.
7. To increase the tree cover in Hull.
8. To encourage provision of bird boxes and supplementary feeding.

What We Are Going to Do

What We Can All Do

• Let the Hull Biodiversity Partnership know if you see Tree Sparrows in Hull.Put up a Tree Sparrow box.
  
  
• Encourage the planting of new hedges around school fields and amenity areas.
  
  
• Feed garden birds, especially in winter and spring.
   

Links With Other Action Plans

Habitat management will be very important for this bird and this plan should be considered in along with those for Trees, Scrub and Hedgerows, Grassland, and Parks, Golf Courses and Cemeteries. It is likely that the implementation of this plan will also benefit other birds such as the Reed Bunting, Skylark, Song Thrush and Linnet.

References

Baillie, S.R., Crick, H.Q.P., Balmer, D.E., Bashford, R.I., Beaven, L.P., Freeman, S.N., Marchant, J.H., Noble, D.G., Raven, M.J., Siriwardena, G.M., Thewlis, R. and Wernham, C.V. (2001) Breeding Birds in the Wider Countryside: their conservation status 2000. BTO Research Report 252. BTO, Thetford. (Retrieved January 2002 from http://www.bto.org/birdtrends)

Broughton, R.K. (2002) The Birds of the Hull Area. Kingston Press, Hull.

Gibbons, D.W. (1993) New Atlas of Breeding Birds in Britain and Ireland: 1988-1991. Poyser, London.

Gregory, R.D., Nobel, D.G., Cranswick, P.A. Rehfisch, M.M., Baillie, S.R. (2001) The State of the UK's Birds. RSPB, BTO, WWT, Sandy.

Marchant, J.H. (1990) Population Trends in British Breeding Birds. British Trust for Ornithology.

RSPB (1996) Birds of Conservation Concern in the United Kingdom, Channel Islands and Isle of Man.

RSPB, Sandy.

RSPB (2000) The Loss of Farmland Birds. RSPB, Sandy.

RSPB (2001) Wild Birds and the Law. RSPB, Sandy.

RSPB, FWAG, The Game Conservancy Trust (2000) Farming for Birds: Tree Sparrow. RSPB, Sandy.