Pesticides and birds: a report on the evidence for changes in farmland bird populations and the proposals for a pesticide tax


Cereals & Oilseeds
Project code:
01 January 2001 - 28 February 2001
AHDB Cereals & Oilseeds.
AHDB sector cost:
£8,000 from the Home-Grown Cereals Authority (Project No 2478)
Project leader:
R T PLUMB and R H BROMILOW IACR Rothamsted, Harpenden, Hertfordshire aL5 2JQ


rr46-final-project-report (1)

About this project


  • The evidence for declines in the populations of some farmland birds is sound and the statistical analyses used are appropriate.
  • The evidence is clear that some of these declines, and other changes in bird populations, are linked to agricultural practice.
  • The contention that pesticides alone are a cause of the changes in bird populations is not generally supported by the evidence. However, pesticides have played a role in agricultural changes that have led to changes in bird populations.
  • Direct effects on birds of correctly used pesticides are minimal. Their most important effect has been in supporting changes in cropping patterns that have altered habitat and food availability.
    There is no evidence in support of the hypothesis that a pesticide tax alone would deliver significant benefits to birds.
  • A pesticide tax hypothecated for agri-environment schemes might generate some benefits for birds but the cost would fall mainly on the arable and horticultural sectors, whereas the increased productivity and stocking rate of grassland, which uses very little pesticide, can have detrimental effects on bird populations.
  • The proposed design and application of a tax are flawed.
  • Some biodiversity indicators have improved over the last 10 years and recent bird population changes have generally shown improvements. For no bird species are the recent population trends worse than in earlier analyses.
  • The role of changes in grassland management on bird populations and survival deserves more attention.
  • A number of influences on agriculture; organic farming, crop assurance, predation, set-aside, new crops and global warming, and their possible effects on birds are briefly discussed.

The farming industry working with conservation organisations is the most likely way of achieving acceptable solutions to the concerns of each and the targets imposed by HMG policy documents.