Effects of cropping practices on declining farmland birds during the breeding season.
Twenty-four species of our farmland birds have declined in abundance over the last few decades, during a period of agricultural intensification. Studies of the grey partridge and of four other bird species have several themes in common: loss of nesting and foraging habitat, drop in numbers of chick-food invertebrates, susceptibility to nest predation. Densities of birds and of their chick-food items have suffered from the polarisation of agriculture towards intensive arable or intensive livestock farming, and changes in practices regarding grassland management, timing of sowing and pesticide use. Where such cropping practices are favourable, for example on traditional mixed arable farms, bird and insect densities can be high. Methods like Conservation Headlands, Beetle Banks and set-aside allow certain aspects of such farming to be reproduced on intensive farms with little economic penalty and considerable conservation benefits to plants, insects and ultimately birds.