The use of winter bird crops by farmland birds in lowland England

Abstract

Winter food for farmland birds can be enhanced by planting seed-rich ‘winter bird crops’ (WBCs), the content of which is highly variable. Data from three winters (October to March in 1998/1999, 1999/2000 and 2000/2001) were used to assess the value of different WBCs for lowland farmland birds in England, based on around 100 plots per winter. Densities of gamebirds, insectivorous and seed-eating passerines were generally higher on WBCs than on conventional crops, stubbles or grassland (except for skylark ( Alauda arvensis) and rook ( Corvus frugilegus). Kale supported high densities of the widest range of bird species (including insectivorous and seed-eating species), quinoa was used by finches and tree sparrows ( Passer montanus), and (unharvested) seeding cereals supported high densities of buntings. Sunflowers, phacelia and buckwheat supported low densities of most bird species. The differences between WBCs were more marked in late winter, owing to better seed retention by kale and quinoa compared with other crops. A combination of kale, quinoa and seeding cereals will support the highest densities of the greatest variety of bird species, but WBC content can also be varied to suit circumstance or species. This study demonstrates the value of WBCs for a wide range of birds, and discusses this with respect to existing ‘agri-environment schemes’, highlighting the need for similar options in pastoral landscapes where seed resources are particularly rare.