Large mixed flocks of seed-eating birds used to be common on farmland, but they are now an increasingly rare sight. Changes in agricultural practices have greatly reduced populations of arable weeds, and this has been bad news not only for the plant species involved, but also for the birds that feed on their seeds. Ian Newton explains why seeds have been lost from the farmed countryside, and describes the effect that this has had on bird populations.
Among the various farmland birds that have declined in Britain over recent decades are the small seed-eaters that feed largely on the seeds of farmland weeds. The widespread use of herbicides, especially on arable land, has by now removed many broadleaved weeds from most of our fields, and has steadily depleted the seed bank in the soil.