Performance and effectiveness of winter bird food patches established under Environmental Stewardship: results from the Hillesden experiment

The Hillesden experiment is a farm-scale study evaluating the performance of options under Environmental Stewardship. We describe bird usage of winter seed patches (20 patches; three seed mixes) in relation to seed depletion and variation between individual patches. Seed retention declined exponentially in all three mixes; 50% depletion occurred by late November, reaching 80-90% before mid January. In mid winter, Fodder Beet retained more seed (c. 80%) than Millet, Kale, Fodder Radish and Triticale (20-40%). Bird numbers peaked in December/early January (seed depletion 70-90%), but declined rapidly in late January coinciding with seed exhaustion. Seed yields varied between patches (minimum < 1% of maximum). If all patches had performed at the maximum, yield would have increased by about 64%. Bird counts also varied greatly between patches, but trends with seed yield were positive. At a farm-scale, winter bird abundance was significantly greater (granivorous species + 415%) when patches were available.