---

---

---

---

Science RSS News Feeds

---

---

Email a Friend Printer Friendly

Ecologists unravel reasons for falling British bird numbers

December 20, 2000

Several papers at the British Ecological Society~s Winter Meeting will help explain why changes in farming practices are having such a disastrous impact on British bird populations. The results will have important implications for bird conservation and farming in Britain.

The meeting, which will be held at the University of Birmingham on 3-5 January 2001, will hear the results of the first controlled comparison of the impact of different grassland systems on British birds. The work is important because most research in the past has focussed on the impact of intensive arable farming on bird numbers. Dave Buckingham of the Royal Society for the Protection of Birds (RSPB) will tell the meeting that early results show that small changes in the way that farmers manage their grazing land can have a major impact on how much food is available to birds, and hence on their populations.

Preliminary results from Buckingham~s study found that the grassland element of organic farming is no better than conventional livestock farming in providing food for birds. This may be because most organic farms are farmed intensively and it is this, rather than artificial pesticides which are little used on grassland anyway, that has most impact on bird populations. The study also found that dairy farms offer particularly poor pickings for birds compared with mixed beef and sheep grazing.

Buckingham~s study involved 400 grass fields on 23 lowland farms in Shropshire, Staffordshire and Cheshire during the winter of 1999-2000 and the 2000 breeding season between April and August.

As well as intensification, there has been a massive reduction in the amount of mixed farming (combinations of arable and livestock) since the second world war. Phil Atkinson of the British Trust for Ornithology (BTO) and Rob Robinson (BTO/RSPB) will tell the meeting about the impact this decline has had on a wide range of farmland bird species. Many farmland birds have specific preferences for certain grass and arable mixtures. Mixed farmland is especially important to birds in winter when several species shifted from grass-dominated areas in summer to areas of mixed farming. Importantly, this study shows that introducing small patches of arable land with grassland can markedly increase some bird populations, such as the skylark, corn bunting and grey partridge. ~Even planting just 10% of a grassland farm with arable crops - equivalent to a 4 hectare field per farm - can have a large effect on bird numbers,~ Atkinson and Robinson say.

The meeting will also hear about the steep decline in the number of lapwings over England and Wales in the last 11 years. The number of lapwing pairs halved between 1987 and 1998, according to research by Andy Wilson of the BTO for the RSPB. Losses have been most dramatic in Wales where lapwing numbers are down 77% to only around 1,700 pairs. Changes in crop sowing regimes, the loss of mixed farming and the intensification of grassland management are highlighted as being important factors in the decline. The survey covered over 1.25 million acres.

Dave Buckingham will present his paper at 3.00 pm on Thursday 4 January, Andy Wilson will present his paper at 10.00 am on Wednesday 3 January, and Phil Atkinson will give his paper at 9.40 am on Wednesday 3 January 2001.

- ends -

Warwick, University of